IGCP 582 Annual Meeting and Conference On TROPICAL RIVERS: HYDRO-PHYSICAL PROCESSES, IMPACTS, HAZARDS AND MANAGEMENT ABSTRACTS Indian Institute of Technology Kanpur 5-7 January 2012 IGCP 582 Annual Meeting and Conference On TROPICAL RIVERS: HYDRO-PHYSICAL PROCESSES, IMPACTS, HAZARDS AND MANAGEMENT CONVENERS Snigdha Ghatak Geological Survey of India New Delhi Rajiv Sinha Indian Institute of Technology Kanpur FINANCIAL ASSISTANCE CONTENTS Page Plenary Session 1. The Fluid Earth V.K. Gaur 1 Session I: River Science and Processes 2. Living with 'disturbed' large river systems: Securing river futures with River Science S.K. Tandon 4 3. Variation in width and Braiding Intensity of the Brahmaputra River in Assam, India J. N. Sarma, M. Phukan and S. Acharjee 5 4. Sediment dynamics and geomorphic connectivity in the Ganga River basin at cross over of scales Vikrant Jain 6 5. Effective discharge for suspended sediment transport in Ganga alluvial plain rivers and its geomorphic effectiveness N.G.Roy & R. Sinha 7 6. Spatio-temporal analysis of stream (Dis)connectivity in the Kosi megafan Kumar Gaurav, Rajiv Sinha, and S.K.Tandon 8 7. Spatial and temporal trend and variability analysis of rainfall series at Seonath river basin, Chhattisgarh Shiulee Chakraborty, R. P. Pandey and U.C Chaube, S.K. Mishra 9 8. Trend and Change-Point Detection for Annual and Seasonal Discharge Series of the Brahmaputra River at the Pandu Hydrological Station, North East. Pratibha Warwade, Nayan Sharma, Ashish Pandey 10 9. Entropy Application to the Evaluation of River Network Equilibrium: A case Study of Kunur River Basin, West Bengal, India Sujay Bandyopadhyay and N.C.Jana 10 10. Channel Pattern Evolution Ganga in Malda District of West Bengal Since 18th Century Susmita Sen Majumder, Gupinath Bhandari & Sankar Chakrabarti 11 11. Morphological variability in the Yamuna River system and role of stream power distribution pattern Nupur Bawa, Vikas Jyani, Parul Tyagi, Vikrant Jain, Shashank Shekhar 12 Session II: Human impacts on river systems and River Management 12. Ganga river basin environment management plan: vision, conceptual framework and guiding principles. Vinod Tare 15 13 Ecosystem based management of rivers: Are we making any efforts towards it? Parineeta Dandekar, Himanshu Thakkar 17 14. Water Quality and Ecosystem Management of Gomti River: A Catchment Planning Approach Venkatesh Dutta and Ravindra Kumar Srivastava 18 15. Evolution of tidal domain as geo-resource - a case study of Creek systems of western Sunderbans Tapan K. Jana, Sudipto Lahiri, Amal K. Samadder, Pranab K. Mitra, Debasish Sengupta & Jyoti Prakash Kumar 19 16. Surface and groundwater interaction in Yamuna river flood plain at Agra endangering the safety of Taj Mahal Ravindra Kumar 20 17. Qualitative assessment of parameters controlling groundwater quality in Sabarmati River Basin Kumari Rina, C. K. Singh, R. P. Singh, Vikas Kamal, Neha Singh, Saumitra Mukherjee 21 18. Remote sensing and GIS based study of dam induced geomorphic changes in the Ganges in the Himalayas. Vikas Kamal, R. P. Singh, Neha Singh, Rina Kumari, Rajesh Kumar, Ritesh Sipolya, Javed Mallick, Saumitra Mukherjee 21 19. Human impact on river system to climate change Aruna Kumari & others 22 20. Impact of Human Activities Gomti River – Lucknow Sangeeta Sachan, Shurti Sharma, Shalini Tripathi 23 21. River (dis)connectivity in Kosi River basin and its temporal and spatial dynamics Rakesh Kumar, Kumar Gaurav, Vikrant Jain, Rajiv Sinha 24 22. Geomorphic response of a river system to urbanization, a study from Yamuna channel reach around Delhi NCR Parul Tyagi, Nupur Bawa, Vikrant Jain 25 23. Historical pollution trends in Tamiraparani river basin, South India R. Arthur James, R. Purvaja and R. Ramesh 26 24. Hydro-geochemical processes and quality assessment of surface, sub-surface and mine water resources in the upper catchment of Damodar River Basin, India Abhay Kumar Singh 26 25. Change in Socio economic vulnerability of the people ex-ante and ex-post of a development project Ajay Katuri 27 26. Valley margin and active floodplain of river Ganga: Defining “river space” S. Ahmad, Lipi Basu, H. Mohanta and R. Sinha 28 27. Eco-geomorphology of ganga river basin based on inputs from satellite data: implications for river management Haridas Mohanta, S. Ahmad, Lipi Basu, R.P. Mathur and R. Sinha 29 Session III: River dynamics and River hazards 28. Understanding the Fluvial Processes Operating in Western Ganga Delta Kalyan Rudra 32 29. Extreme Floods in the Indian Subcontinent during the 20th Century V.S. Kale 33 30. Human induced riverbank hazard in Kathmandu valley, Nepal A.P. Gajurel, D. Pathak, G. B. Shrestha and S. K. Dwivedi 33 31. Bank Stability Analysis around Majuli Island, Assam M.K.Dutta, R. Goswami, and S Barman 34 32. River Channel Adjustment to Meander Cutoffs in Part of River Godavari Maya Unde 35 33. Tectonic fabric, physiographic patterns and issues of stream dynamics of Himalayan rivers Devashis Chatterjee 36 34. Flood inundation mapping of Savitri river floods- A case study of Mahad city and surrounding region with the help of GIS Priyadarshani Baburao More, V.R.Nagarale, P.P. Magar 37 35. The response of drainage basins to the late Quaternary tectonics in the Sabarmati River basin, Gujarat, Western India Girish Ch. Kothyari, Siddartha Prizamawala, Vamdev Pathak, Prabhin Sukumaran and Mukesh Chauhan 38 36. Flood hazard studies in Nagappatinam district, Tamilnadu, India R.Baskaran 39 37. Study of bankline changes of a stretch of River Ganga in Bihar using multi temporal Remote Sensing data. Shankar Dayal, Atul Aditya Pandey, Ramesh Shukla and V.S. Dube 39 38. Vulnerability analysis in parts of Ravi Basin, Chamba District, Himachal Pradesh Pankaj Kumar, Arpita Pankaj, S.K.Ghildyal, R.K.Avasthy 40 Session IV: River response to climate change 39. Fluvial systems of Gujarat in a climate change perspective: An analysis of palaeohydrology, palaeodischarge and palaeochannel dimensions Alpa Sridhar and L. S. Chamyal 44 40. Decadal variation in the discharge of Chhota Shigri stream waters Lahaul-Spiti valley, Himachal Pradesh Alagappan Ramanathan, Parmanand Sharma Pottakkal George Jose and Anurag Linda 44 41. Aggradation during the Early Holocene Strengthened NE Monsoon and Rapid Recent incision of the Coastal Tropical Rivers, Chennai, Tamil Nadu. Achyuthan H. and Nagasundram M. 45 42. Palaeoclimatic and Tectonic Influences on alluvial sedimentation of Tapi basin, Central India Snigdha Ghatak, Mriganka Ghatak, Anjan Kumar Chatterjee 47 43. Influence of tectonics and climate on Holocene Bajada sedimentation along Narmada-Son Fault (NSF), Gujarat, Western India Parul N. Joshi, D. M. Maurya and L. S. Chamyal 48 44. Sediment storage and evacuation episodes during the Late Quaternary in the Western Dehradun region: A GIS approach Swati Sinha, R. Sinha, Alexander Densmore 48 45. Complex scenario of fluvial geomorphologic responses to glacial melting: A first order synthesis for the Himalayan rivers L. Sardine Varay and Vikrant Jain 49 46. The Camoebians and Palynological Assemblage in the Tributary of Uppanar River, Cauvery Delta, India: Environment and Sea level since 4000 yrs Jyoti Srivastava, Anjum Farooqui and S.M Hussain 50 Session V: River landscape evolution, subsurface stratigraphy and sediment geochemistry 47. Geomorphological study of the land forms produced by the tropical rivers and land use in Bagmara Upazilla, Rajshahi district, northwestern Bangladesh Mrinal Kanti Roy, Md. Aynul Haque and Raman Kumar Biswas 52 48. Evidences for buried channels of a large river in the ghaggar plains, northwest India Ajit Singh, Rajiv Sinha, Sanjeev Gupta, Andrew Carter, Debajyoti Paul and Philippa Mason 53 49. Late Quaternary Sedimentation controls in the intermontane valleys of NW Himalaya Vimal Singh 54 50. Sr isotopic Signatures of Surface water, Groundwater and Sediments of Gomati River around Lucknow in Ganga Alluvial Plain, India Sandeep Singh, Munendra Singh, Vipin Paliwal, K G Geetumol, Anurag Srivastava, Nupur Srivastava and A.K. Choudhary 55 51. Source-to-Sink studies of dryland tropical fluvial system : A case study from Rukmavati river, Kachchh, Western India Nilesh Bhatt, S. P. Prizomwala and N. Basavaiah 56 52. Distribution and Speciation of Selected Heavy Metals in the Surface Sediments from an Estuary in Coleroon river, East Coast of India. Ramkumar T, Anithamary I, Venkatramanan S, Gnanachandrasamy,G. S.Vasudevan 57 53. Topologic properties of drainage network on the megafan surface and its implications for the development of megafans Arindam Misra, Parthasarathi Ghosh, Tapan Chakraborty 57 54. National Geomorphological Mapping in India and its relevance to River Basin Research and Management – An overview Lalan Prasad Singh and V. Singa Raju 59 55. The Sone megafan and the possibility of its existence in the marginal parts of Ganga basin in India Sudarsan Sahu 60 56. Shallow subsurface stratigraphy of megafans in north Bihar plains using electrical resistivity sounding and borehole data Jawed Ahmad, Gaurav Kumar, Guillaume Morin and R. Sinha 62 57. Landscape evolution and geomorphology of the Tangtse River valley (Ladakh), NW Indian Himalaya Binita Phartiyal, Randheer Singh, Girish Ch. Kothyari and Anupam Sharma 63 58. Evolution of Srinagar (Garhwal) Valley Landforms: Response of Alaknanda River to Climate Change or Result of Interaction Between Main River (Alaknanda River) and Local Streams Rahul Devrani and Vimal Singh 64 59. Shrinking wetlands in West Bengal: a case study from Hoogly-Damodar Interfluve and East Kolkata Wetland area Arindam Mishra, Shantanu Sarkar, Sayan Sinha, Tapan Chakraborty 65 60. GIS-based Morphometric analysis of Tons River Basin with Special Reference to Tectonic Upliftment Arpita Pankaj, Pankaj Kumar and Ajai Mishra 66 61 Landscape evolution and morphological characterization of drainage network of Corbyn Rivulet, South Andaman Islands, India – A Ground Penetrating Radar (GPR) and Remote Sensing Study. Shrikant Maury and S.Balaji 67 62. Grain Size and geochemical analysis of the sediments of the Brahmaputra River and five of its tributaries Sumi Handique and N. Senapati. 67 63. Elemental Mobility during Weathering of the Ganga Alluvial Plain: a case study of the Gomati River, northern India Rohit Kuvar, Sandeep Singh, A. K. Choudhary and Munendra Singh 68 64. Geochemistry and weathering history of buried river sediments from Ghaggar plains, NW India Manu Rastogi, Ajit Singh, Debajyoti Paul, and Rajiv Sinha 69 IGCP 582: IIT Kanpur, January 2012 Plenary Session THE FLUID EARTH Vinod K Gaur CSIR Centre for Mathematical Modeling, Indian Institute of Astrophysics, Bangalore Material flows on various scales from solid state creep to stream torrents, constitute the basic processes that have fashioned planet earth and its environment by ceaselessly cycling energy and matter through its various spheres. The works of a host of earth elements: wind and ocean currents, river, debris, geyser and lava flows, and the movement of groundwater that nourishes many an ecological systems including the human, and maintains stream flows during dry periods, are all fluid mediated processes. Indeed rock melting and its ascent in the earth‟s lithosphere is the prime dynamical process that sustains plate tectonics and results in the creation of its new topographies, setting in motion consequential gravity flows that redistribute sediments and chemical nutrients downstream , setting the scene for the evolution and sustenance of specific ecological niches. Yet this view of planet earth as being essentially a fluid body was long eclipsed despite an intuitive recognition that had led Newton to numerically demonstrate that the earth‟s equatorial bulge could be explained as a natural consequence of a rotating fluid sphere. However, following the discovery of radioactivity towards the close of the 19th century and the speculative existence of convection in the earth‟s mantle several decades later, since made more definitive in the wake of Plate Tectonics, earth scientists began to explore the finer aspects of geological processes such as the ubiquitous two-phase flows in the earth system both at high Reynold‟s numbers as in the flows of atmospheric particles and sediments, and crystallization in magma chambers, as well as low Reynold‟s numbers: sediment compaction, metamorphism and reservoir engineering. Incisive new insights were thus created by modeling earth processes as fluid dynamical systems, to better understand their evolution: sediment diagenesis, fluid interactions during metamorphism, migmatization, lower crust and upper mantle, geochemistry, river and coastal pollution, waste disposal and groundwater regimes, to name some. However, Indian contributions to such cutting edge global earth science endeavours have not registered a significant presence, as they continue to be largely confined to mapping and correlations with analogous occurrences. But many of our modern day concerns centre on problems related to shifting environments mediated by fluid dynamical processes: design of engineered habitats and river systems, maintenance of ecologically wholesome stream and groundwater flows, stabilization of slopes, creative urban land use design sensible to local and regional topography that control the various gravity driven flows, soil conservation, waste and effluent treatment, and preservation of critical ecosystems such as water bodies, forests and wetlands that provide the sustaining ecosystem services. Clearly some initiatives are required to infuse the Indian scene of geological sciences with deeper analytical illumination and abilities to model earth systems both mathematically and on the computer. This is not as difficult as assumed, which may be the main impediment 1 IGCP 582: IIT Kanpur, January 2012 behind the continuing diffidence. Institutions such as the IITs are admirably placed to provide these initiatives and the challenge to design academic and research programmes that by exploiting the intuitive recognition of structural homologies and dynamical similitude simplifies overt mathematization of earth issues, could prove exciting both to students and their mentors. The lecture will expose the basic conceptual elements needed for describing the dynamic regimes of fluid like materials and approaches to working out solutions to some of the problems outlined above. 2 IGCP 582: IIT Kanpur, January 2012 Session I River Science and Processes 3 IGCP 582: IIT Kanpur, January 2012 LIVING WITH 'DISTURBED' LARGE RIVER SYSTEMS: SECURING RIVER FUTURES WITH RIVER SCIENCE S.K. Tandon Professor Emeritus, University of Delhi and Distinguished Professor, Shiv Nadar University, G. Noida Large river systems in the tropics and elsewhere constitute one of the most fundamental and enduring life support systems that have sustained civilisations in the past and the present; and will remain a critical factor in determining the future security of civilisations. In a world that is expected to support 9 to 10 billion people by the middle of the current century, and a world that is likely to be impacted by an unprecedented rate of global change, the main agenda for sustainability will be centred on developing dynamic strategies for the management of freshwater systems, most importantly large river systems. As large river systems constitute a lifeline for the future of several river valley civilisations, it is important to understand their complexity as coupled social-environmental systems. River engineering deals with the interventions that humans make in river systems in order to use them, and essentially considers these systems on short time scales (annual, decadal and century) without placing them in an evolutionary perspective. In the future, the dependence of humans on the large river systems will increase because of growing populations. Should we continue to create 'disturbances' at different scales in these systems without obtaining a detailed multi-disciplinary knowledge base of these systems? Human disturbance of different types at different scales in large river systems is a consequence of the perceived needs of riverine communities/societies; these needs should be in consonance with the 'needs' of the river itself. How do we arrive at a harmonious relationship between human societies and the river basins that are occupied by them? The practice of river science is one step in this direction. River Science is an integrative multidisciplinary subject that includes the study of interactions amongst hydrological, geological, chemical and ecological processes; and their influence on the form and dynamics of riverine ecosystems. Also, river science includes the relationships between watersheds, riparian zones, floodplains, groundwater, headwaters and downstream rivers (USGS, 2010). Most large river systems provide critical ecosystem sources to large populations in S.Asia. Considerable pressure is exerted by about a billion-strong population on these river systems. Human in this region have impacted large river systems by water abstraction for irrigation, by pollution through industrial and urban expansion, as well as reduction in connectivity by the construction of many large dams, barrages and related engineering structures. River engineering should be based on a priori knowledge of river science for building harmonious 'human-river' relationships that replace the earlier 'command and control' exploitative approaches. It needs to be emphasised that 'disturbed' large river systems cannot be investigated in a reductionist discipline specific mode as the "whole exceeds the sum of the parts", and that integration of data by multi-disciplinary teams across various spatial and time scales needs to be encouraged. 4 IGCP 582: IIT Kanpur, January 2012 VARIATION IN WIDTH AND BRAIDING INTENSITY OF THE BRAHMAPUTRA RIVER IN ASSAM, INDIA J. N. Sarma*, M. Phukan and S. Acharjee Department of Applied Geology, Dibrugarh UniversityDibrugarh - 786004, Assam, INDIA *Email: jnsdu@yahoo.com The Brahmaputra River is a large international river flowing through Tibet (China), India and Bangladesh. The slope of the river decreases suddenly in front of the Himalayas and results in the deposition of sediment and development of a braided channel. It flows through Assam, India, for about 670 km along a valley comprising recent alluvium. In Assam the basin receives about 300 cm mean annual rainfall. Very high seismicity of the area and some climatic factors lead to morphological changes of the river from time to time. This article attempts to assess variation in width and braiding index (BI) of the river using the SOI maps of 1963/1975 and satellite data of 1996 and 2008. The river has a nearly east-west trending course in Assam. Hence the width and BI are measured perpendicular to the two banklines at the same fixed geographical points for the three data sequences at every 5 /E longitudinal interval. The mean width the Brahmaputra River channel in Assam in maps of 1913/28 was 5739.73 m, which increased to 7252.30 m by 1963/1975. In 1996 the mean width of the channel was 7295 m, which was slightly greater than that of the former sequence (1963/1975). In the year 1998 the mean width became 8731 m, which infers a significant widening of the channel as compared to 1996.Braiding index (BI) is calculated following Brice (1960, 1964). Although the Brahmaputra is a braided river, in three short narrow reaches, the river does not develop braiding as BI is much less than 1.5. The average BI for the entire Brahmaputra in Assam for 1963-75 and 1966 were 8.46 and 8.74 respectively, indicating a slight increase in braiding in the later period. Out of a total of 68 segments there are 32 segments where the BI of the river had increased and 36 segments where the BI had decreased in 1996 as compared to the period of 1963-75. But BI decreased to only 5.04 in 2008. The relationship between variation in width and the BI in different periods of data reveals that out of the 68 segments majority of the variations are of similar type, i.e. an increase in width associated with an increase in BI was found in 21 segments (30.88%), as well as an decrease in width with decline in BI was recorded in 18 segments (26.47%). On the other hand contradictory type of variation, e.g. an increase in width leading to decrease in BI was found in 18 segments (26.47%) and decrease in width leading to increase in BI in 11 segments (16.18%). The overall similar variation was 57.35% as compared to dissimilar variation of 42.65%. Hence it may be concluded that the variation in width may have some influence on the variation of the BI of the Brahmaputra River. 5 IGCP 582: IIT Kanpur, January 2012 SEDIMENT DYNAMICS AND GEOMORPHIC CONNECTIVITY IN THE GANGA RIVER BASIN AT CROSS OVER OF SCALES Vikrant Jain Department of Geology, Centre of Advanced Studies, University of Delhi, Delhi Email: vjain@geology.du.ac.in Geomorphic connectivity has recently developed into a significant parameter to analyse river response to external forcing, flux movement in a river basin, and to define future of river health. Connectivity can be defined on the basis of longitudinal, lateral and vertical dimensions, however its significance and strength varies at different spatial and temporal scales. Geomorphic connectivity has been analysed either on the basis of flux movement (functional connectivity) or physical connectedness (structural connectivity) or a combination of both1. In the current study sediment movement data across different compartments (landforms) of the Ganga River Basin has been synthesized at different spatial and temporal scales to analyse geomorphic processes and feedback mechanism in a river basin. Basin scale sediment residence time for the Ganga River dispersal system using different approaches suggest conflicting results. Diffusion equation based analysis of floodplain buffering suggest basin scale residence time as 1 million years2, while variation in sediment budgeting at delta plains are interpreted on the basis of sediment residence time of 2-3 ka only3. The basin scale variability further gets complex when sediment dynamics and geomorphic connectivity is analysed at sub-basin (tributary catchment) scale. Source-sink connectivity in Rapti and Ghaghra River on the basis of Ur-Th disequilibrium series are reported at time scale of 100-250 years4. Modern sediment load data also highlights significance of buffering effect of channel bars and floodplains, as only less than 45% of sediment at Bangladesh is actually reaching in the delta plains4. It indicates that the Himalayan-Delta system will be mostly disconnected at smaller time scale. Within sub-basins, different geological landscapes are characterized by variable sediment contribution. In the Alaknanda River, geochemical data suggests that Tethys Himalaya is disconnected with Ganga River basin5, while in the Baghmati river basin Lesser Himalaya is mostly disconnected with downstream reaches. Deposition and erosion of sediments trapped in intermontane valleys in the western Himalaya have amplified climate-driven variations in sediment supply in the Ganga system6. Within intermontane valley, smaller rivers with channel length of few kilometers show disconnection at 40 ka time scale. Further, reach scale aggradation-degradation variation along a river also adds complexity in source-sink connectivity in a river basin. Fluvial landforms in the Ganga Plains at different scales are characterized by variable (dis)connectivity. This indicates that some part of sub-basins (connected landforms) will be more sensitivity to erosion processes in comparison to the other parts of the basin (disconnected part). Therefore, similar external forcing will not result similar effect in downstream sedimentary archive due to differential sensitivity, and will result nonlinear river response to similar forcing. There is a need to map the disconnected landforms in the Ganga River basin at cross over of scales. An in depth analysis of the geomorphic connectivity will provide better understanding about nonlinear river response to external forcing and will help to predict its future in the uncertain scenario of climate change and anthropogenic effects. 6 IGCP 582: IIT Kanpur, January 2012 EFFECTIVE DISCHARGE FOR SUSPENDED SEDIMENT TRANSPORT IN GANGA ALLUVIAL PLAIN RIVERS AND ITS GEOMORPHIC EFFECTIVENESS N.G. Roy1 & R. Sinha2 1 Department of Petroleum Engineering & Earth Sciences, University of Petroleum & Energy Studies, Dehradun; E-mail: ngroy1404@gmail.com 2 Engineering Geoscience Group, Department of Civil Engineering, IIT Kanpur Effective discharge analysis of suspended sediment transport has been lacking for Gangetic alluvial rivers. Since stream restoration is entirely controlled by effective discharge variable and some effective discharges are most important for driving particular ecological processes in fluvial system, therefore it is important to have routine measurement of effective flow through river channel, besides other probabilistic flows. The effective discharges for suspended sediment transport in western Ganga alluvial plains are computed using both power curve and alternative “mean approach”. Furthermore, sediment transport here is greatly dominated by movement of material in suspension and no attempt has been made to measure accurately the small amount of bedload transport in these rivers. The estimations of effective discharge are also compared with other deterministic & probabilistic discharges, such as bankfull discharge (Qbf) and discharges of certain recurrence interval (Qri). Thirty years of mean daily discharge from various sites of the western Ganga plains have been assessed and the abundance of the discharge occurrence has been assigned, according to 20 classes. It was noticed from the recorded data that less than 40% of flows cause effective sediment transport in the western Ganga alluvial rivers, which can be considered as effective discharge for suspended sediment transport. Alternatively, 50% of sediment load for all studied site was moved by between 14% and 40% of the total discharge. Effective discharges calculated over the period of record are well below bankfull level; however few maximum events are close to bankfull level, which have high return value (RI > 40 years). The mean annual discharge (RI=2.33 yrs) can transport only 0 to 10% of the total sediment. Both the discharges are therefore not efficient for effective sediment transport in this region. The geomorphic effectiveness of this discharge is investigated through temporal changes in channel geomorphology at various sites. Changes in cross-sectional area at various sites are manifested by sediment a storage and removal process, which is controlled by effective discharge through the channel. Effective discharge flow through the channels shows good adjustment of channel cross-section to the flow and does not affect channel margin geometry. While less frequent, high magnitude bankfull discharge can be able to modify the channel margin geometry. Further assessment noticed that all the effective discharges are well below bankfull discharges, thereby flow lines get concentrated to thalweg erosion and channel get incised by frequent flow of effective discharges. When the high frequency flows are not geomorphologically effective enough, then these flows characterise high degree of stationarity and cause frequent channel avulsion as observed along one of the tributary channel of the Ganga. 7 IGCP 582: IIT Kanpur, January 2012 SPATIO-TEMPORAL ANALYSIS OF STREAM (DIS)CONNECTIVITY IN THE KOSI MEGAFAN Kumar Gaurav1, Rajiv Sinha1, and S.K.Tandon2 1 Department of Civil Engineering, Indian Institute of Technology, Kanpur - 208016 2 Department of Geology, University of Delhi, Delhi - 110007, INDIA Email: kgaurav@iitk.ac.in; rsinha@iitk.ac.in; sktand@rediffmail.com Connectivity has become one of the important evolving concepts in fluvial geomorphology to understand channel processes, river dynamics and sediment transfer in a river basin. The great avulsion of the Kosi river in year 2008 caused significant changes in the geomorphology of the Kosi megafan in terms of formation of new channels as well as filling up of some older courses. We have attempted to analyse these changes in a connectivity perspective. A study window of 155 km2 area was selected for stream connectivity analysis in the Kosi megafan region. The study area was divided into various grids of 200×200 meters to anlyse the spatial variability in connectivity structure while the temporal variability was analysed through the multidate Landsat images of year 2005, 2009 and 2010. Connectivity structure of the drainage network was worked out on the basis of physical contact (structural connectivity, SC) or transfer of material (functional connectivity, FC). We have identified four fundamental types of connectivity in the study area namely, (1) active connected system (full SC and FC) (2) partially connected system (full SC, partial FC), (3) inactive connected system (full SC but no FC), and (4) disconnected system (both SC and FC partial or none). Stream lengths corresponding to each class of connectivity were used as a measure of connectivity structure at a given time. A detailed mapping of four types of connectivity structure of stream networks for three different years was carried out using satellite images and digital elevation data. In order to visualize the functional connectivity better, Normalize differential water index (NDWI) was also generated to enhance the water features on the remotely sensed digital imagery. Further, the proportions of stream length in each connectivity class through time were used to quantify the change within the various connectivity classes. A change detection matrix was generated to quantify the percent wise change in different connectivity class grid through the time. The result of grid wise change detection shows a distinct increase of ~ 5% and ~ 9% in active connected streams class grid whereas a decline of ~ 6% and ~ 8% has been observed in disconnected and partially disconnected connectivity class grid in year 2009 and 2010 respectively. This study clearly reveals that the connectivity structure of stream in the region is very dynamic and it keeps modifying itself through the time. The Kosi megafan surface has a dense network of paleochannels which often act as possible pathways of excess water flow in these surfaces. We argue that temporal changes in connectivity structure can be used as predictor for future avulsions, and therefore, continuous monitoring of the connectivity structure including seepage channels may be extremely rewarding for this purpose. 8 IGCP 582: IIT Kanpur, January 2012 SPATIAL AND TEMPORAL TREND AND VARAIBILITY ANALYSIS OF RAINFALL SERIES AT SEONATH RIVER BASIN, CHHATTISGARH (INDIA) Shiulee Chakraborty 1*, R. P. Pandey2 and U.C Chaube3, S.K. Mishra4 1* Department of Water Resources Development and Management, IIT Roorkee, E-mail: schakraborty714@gmail.com 2 National Institute of Hydrology Roorkee-, E-mail: rppanndey@gmail.com 3, 4 Professor, Department of Water Resources Development and Management, IIT Roorkee, E-mail: ucchaube@iitr.ernet.in., skm61fwt@iitr.ernet.in In the present investigation, an attempt has been made to study the spatial and temporal variability of rainfall of 24 rain gauge stations at Seonath sub basin in Chhattisgarh State (India) over the period of 49 years (1960-2008). For homogeneity of rainfall data, double mass curve approach was used. Lag-1 autocorrelation coefficient was used to detect the presence of serially correlation in data series. Mann-Kendall (MK) or Modified MannKendall test (MMK) (non-parametric) and Spearman‟s rho test (parametric) were applied to detect the trend. Sen‟s slope estimate was performed on respective time series variables to detect monotonic trend direction and magnitude of change over time on annual and seasonal basis. The cumulative deviations and CUSUM test was applied to detect possible change points in annual and seasonal precipitation series ((summer, winter and monsoon). Linear time series slopes are analyzed using ArcGIS 9.3 to investigate the spatial trends on the seasonal and annual basis. The Coefficient of Variation (CV) and Normalised Rainfall Variability Index (NRVI) were used for rainfall variability analysis while Precipitation Concentration Index (PCI) was used to detect precipitation concentrations and the associated spatial patterns. According to both parametric and non-parametric test decreasing trend was found in annual and seasonal rainfall series for the entire Seonath sub basin. The maximum decrease in annual rainfall was found in Bodala station (-13.8mm/year) and minimum at Simga station (0.1mm/year). The results indicated an overall downward trend in annual and seasonal rainfalls by both trend techniques. The result shows that the most probable year of change in annual rainfall in the study area is 1986. The result of trend test for two separate periods before the change point (1960-1986) and after the change point (1987-2008) indicated, increase in rainfall was detected before the change year but there was decrease in rainfall after the change point except the summer season (7.51%) and maximum decrease was found in winter season (-12.87%). The CV revealed that inter-annual variability was high in the whole river basin, with values ranging from 22.03% to more than 40% but there were indications of an increase in monthly rainfall concentration by PCI value more 20 for all the stations. NRVI indicated high annual and seasonal rainfall variability during 19751986, and it was of the lowest order during 1987 onwards in almost all the stations. 9 IGCP 582: IIT Kanpur, January 2012 TREND AND CHANGE-POINT DETECTION FOR ANNUAL AND SEASONAL DISCHARGE SERIES OF THE BRAHMAPUTRA RIVER AT THE PANDU HYDROLOGICAL STATION, NORTH EAST, INDIA Pratibha Warwade1*, Nayan Sharma2, Ashish Pandey3 1* Department of Water Resources Development and Management, IIT Roorkee, Roorkee 2,3 Department of Water Resources Development and Management, IIT Roorkee, India, E-mail: pratibhawarwade@gmail.com; nayanfwt@iitr.ernet.in, ashishfwt@iitr.ernet.in The trend test, percentage change and change-point analysis have been carried out on annual and seasonal discharge (monsoon, post monsoon, winter and summer) series of the Brahmaputra River at the Pandu hydrological station, during the period 1971–2008.To identify the trend in all the series of river discharge, both non-parametric (Mann-Kendall and Spearman‟s rho) and parametric (Linear Regression) test were applied. The results of both the trend tests shows that, at 5% significance level, the winter flood series did not have any statistically significant trend, but the annual, monsoon, post monsoon and summer flow series exhibited a sign of decreasing trend at the Pandu station. Sen‟s slope estimates were performed to detect monotonic trend direction and magnitude of change over time, according to Sen‟s test decreasing trend magnitude was observed for annual and seasonal time series. Highest decreasing percentage magnitude was observed in post monsoon series (-28.81 %) followed by monsoon (-26.19%), annual (-25.90%) and summer (-22.74%) flow series over the past 31 years. There was not more than 10 % change was obtained in winter discharge series. For change-point detection, a CUSUM and Cumulative deviation test were used to study the abrupt change in the mean levels of the time series. The results of the change point detection showed that, the most probable change year 1999 was identified at 5% level of significance during the 1971-2008. Series divided in two parts 1971-1999 and 2000 to 2008, discharge was higher during the earlier period (1971-1999) and lower in later period (20002008), finally seems that it was started to decrease after the change point. ENTROPY APPLICATION TO THE EVALUATION OF RIVER NETWORK EQUILIBRIUM: A CASE STUDY OF KUNUR RIVER BASIN, WEST BENGAL, INDIA Sujay Bandyopadhyay1 ‫ ٭‬and N.C. Jana2 1 PhD Student, Dept. of Geography, The University of Burdwan, Burdwan, W.B., India E-mail: sujaybandyopadhyayest@gmail.com/ sujay_bandyopadhyay@yahoo.co.in 2 Reader and Head, Dept. of Geography, The University of Burdwan, Burdwan, W.B., India The river network analysis using the entropy approach manifest the concept of dynamic balance guides the fluvial system. In 1962, Leopold and Langbein introduced the concepts of physical entropy to study the behaviour of streams and evaluation of fluvial morphology. According to these authors, by analogy with thermodynamic entropy, it is postulated that a geomorphologic system like the fluvial network is an open system in a permanent state regime. Under this assumption that the only information available on a drainage basin is its mean elevation, by which the connection between entropy and potential energy is explored to analyze drainage basin morphological characteristics. Yang (1971) has adopted the energy and entropy concepts of Leopold and Langbein to verify the type of relationship that exists among the different fluvial orders as well as to select the ordering that better represents the dynamicity of a drainage network. He tried to explain the drainage network formation and the origin of meanders and the transportation of sediments. He also developed the theory of average rivers fall and the theory of minimum energy expenditure of 10 IGCP 582: IIT Kanpur, January 2012 the fluvial system, affirming that the rivers during their evolution towards an equilibrium condition choose their way so that the potential energy dispersion rate by water mass unit is minimum. However, he warned that the model is applicable to those rivers that have attained the condition of dynamic equilibrium, that is, for rivers that during the process of reaching the final static equilibrium have readjusted so that there is a balance between the work done and the carried sediments. In the present context, the Yang (1971) methodology has been applied to the Kunur River Basin (between 2325'N and 2340'N latitudes, 8715'E and 8754'E longitudes) that is a right bank tributary of the River Ajay and both are part of the River Bhagirathi (a distributary of Ganga). The river is only 112 kilometres (70 miles) in length and the basin is elongated, which comprises an area of 826.5 km2, has its origin near Bansgara in the Faridpur police station area. During the monsoon months the River Kunur with adequate water from its catchment areas contributes to frequent flooding in the large areas of Aushgram and Mangalkote police stations of Barddhaman District. The objective of the present paper is: (i) to verify the level of adjustment for its present longitudinal profile to the calculated and equilibrium longitudinal profiles, and (ii) to assess the degree/magnitude of erosion by the application of this method. The entropy based verification have been applied to the stability/instability analysis of the River Kunur that indicates the nature of fluvial changes, which is an important tool to comprehend the structure, function and dynamics of its ecosystem that enables the hydrologists and environmental experts towards the restoration of a river. CHANNEL PATTERN EVOLUTION OF GANGA IN MALDA DISTRICT OF WEST BENGAL SINCE 18TH CENTURY Susmita Sen Majumder1, Gupinath Bhandari2* & Sankar Chakrabarti3 Department of Civil Engineering, Jadavpur University, Kolkata 700032, India The river Ganga is the most important tropical river of the globe having a source in Gangotri glacier of Himalaya, passing through different states of India and enters West Bengal after swinging the Rajmahal hill and then starts flowing south. Below Rajmahal hill the part of course of Ganga drained through Malda district of West Bengal has been taken as the study area extending from 1964 km to 2051 km chainage of the river course. From Rajmahal hill Ganga starts its old stage which is characterized by the different fluvial landforms on its extensive flat floodplain area like, well developed meanders, cut-off meanders, abandoned channels, oxbow lakes, meander scrolls etc. In this stretch the river is subjected to frequent channel shifting as it flows through its alluvial stage in this region. The river positions have been considered from the available maps, since 18th century (1763-2011) for the present study. The present study considers the assessment of channel oscillation, the evolution of channel pattern with the passage of time, dynamic nature of the islands and the intensity of the meandering pattern. To construct the historical channel oscillation cycle, the historical maps and recent satellite imageries have been studied. The first systematic map of Bengal, surveyed by Rennell during 1763 - 1777 has been used in the study. The other maps used are, Revenue Map of Malda district surveyed during 1847 -‟49, the block maps of 1929 -‟31 and the map of Bengal of 1948, topographic sheets of 1970 -‟71 published by Survey of India. The corona satellite photograph of 1962 has also been used. The present study also includes the LANDSAT satellite imageries from 1973 to 2011. 11 IGCP 582: IIT Kanpur, January 2012 The old course of river Ganga prior to eighteenth century have been attempted to demarcate on the basis of the available historical accounts. The channel morphometry indices (sinuosity index and braiding index) have been analyzed to identify the channel pattern, dynamics of channel landscaping and island formation. A statistical database and graphs have also been made to represent the rate of channel bank shifting and the rates of channel widening/narrowing. The process of channel bank shifting with scouring of riverbank has resulted localized loss of land in the study area. This has a great impact in the surrounding landuse pattern accompanied by the loss of social and individual properties and making the peoples‟ life miserable. Some measures have been taken for river bank protection by constructing different types of embankments like, boulder pitching, boulder pitched earthen embankment, porcupine and boulder gabion embankment. But most of these could not produce fruitful result and further land encroachment was occurred. The breaching of embankment and the increased sediment load took the river in a more vulnerable situation. Considering this and the ill effect of the riverbank protection, an attempt has been made to establish some prediction of river bank erosion in the study area by analyzing the meander components like cut-off ratio, radius of curvature, angle of swing etc. It is expected that the outcome of the present study may provide a reasonable prediction of river shifting at the study area, which would be useful for the future planning on social development at and around this area. MORPHOLOGICAL VARIABILITY IN THE YAMUNA RIVER SYSTEM AND ROLE OF STREAM POWER DISTRIBUTION PATTERN Nupur Bawa, Vikas Jyani, Parul Tyagi, Vikrant Jain, Shashank Shekhar Department of Geology, University of Delhi, Delhi-110007 Stream management planning of a river system is governed by it morphology and channel processes. Morphological diversity is one of the basic parameter to define river health because a river with significant morphological variability is characterized by higher biodiversity and better ecosystem. The present work comprises geomorphic analysis through River Styles mapping of the Yamuna River from upstream of Paonta Sahib in Himanchal to Agra in Uttar Pradesh. Six River Styles were identified based on hierarchical river character that included landscape setting, valley setting, channel confinement and characteristic, geomorphic features and land use cover association. Reach 1, 2, 3 are present in the Himalayan bedrock valley setting with a wider valley at reach 1 and moderate valleys in reach 2 and 3. Further, three types of valley settings i.e. confined, unconfined and partly confined were observed in these reaches. In a confined valley setting, channel abuts directly against bedrock whereas in case of unconfined valley, channel is not imposed by boundary and can mold and rework its boundaries. Along partly confined setting, channel is partly confined with the bedrock and sometimes the vertical adjustments are limited due to the stability of the bedrock valley floor. Reaches 4, 5, 6 have alluvial valley setting. Also, in terms of channel confinement reach 4 and 6 are located in unconfined settings with wide valleys because of their ability to rework the sediments present on the valley floor whereas reach 5 is located in partly confined setting. All River Style reaches were further mapped at smaller scales, where types of bar, channel area and floodplains are mapped and bar area, channel area and channel morphometric parameters were computed. The values are used to characterize each River Styles reaches. Causes for morphological variation are analyzed through downstream variation in the driving forces in channel, which is represented by stream power. A catchment scale stream 12 IGCP 582: IIT Kanpur, January 2012 power distribution pattern was generated using SRTM DEM data and discharge-area relationship for the basin. The stream power pattern shows variable pattern and closely relates with the local slope variability in the area. The average values of the stream power were then compared at each reach. Reach 1, 2, 3 show higher values of the stream power because of the site present at a steeper slope in the Himalayan region. Reach 4 and 5 show a drastic reduction in the stream power followed by reach 6 where average steam power increases again. Reach 1 is characterized by higher stream power, which is responsible for less bar area in confined valley setting. Reach 2 has a partly confined channel, where floodplains are present only on the right bank of the river. Stream power is slightly less than at reach 1, which supports partly confined valley setting. Reach 3 has a confined channel with bedrock or the terraces along the channel banks and is again characterized by higher stream power. However, bar deposition at this reach is higher than reach 2, which indicates an increase in the sediment supply. At reach 4, channel is unconfined and the width of the valley has increased. Stream power is significant less in alluvial plains area, which has resulted in the development of the flood plains on both sides of the river and increase in total bar area. Reach 5 shows a partly confined channel, with wide channel valley and characterized by stream power similar to reach 4. A reduction in the bar area indicates decrease in sediment supply due to extensive bar deposition in upstream reaches. Reach 6 is unconfined with active flood plains in both the sides. Side bars and point bars are dominantly available but they are smaller in area. This detailed morphological assessment brings out the understanding of channel processes, its natural capability to adjust and depicts the inherent character of the river. It will provide the basis to develop ecosystem based management for the river in future. 13 IGCP 582: IIT Kanpur, January 2012 Session II Human Impacts on river systems and River Management 14 IGCP 582: IIT Kanpur, January 2012 GANGA RIVER BASIN ENVIRONMENT MANAGEMENT PLAN: VISION, CONCEPTUAL FRAMEWORK AND GUIDING PRINCIPLES Vinod Tare Professor, Environmental Engineering and Management, Department of Civil Engineering, IIT Kanpur Wide ranging consultations with various stakeholders suggests that the Ganga River Basin Environment Management Plan (GRB EMP) plan should be consistent with the premise that river Ganga (i) is life-like persona as “Mother Ganga” which is considered holy by most Indians; (ii) is to be viewed as World‟s Natural Heritage*; and (iii) along with its tributaries provide material, spiritual and cultural sustenance to millions of inhabitants of the Ganga River Basin. Vision: The overarching objective of the GRB EMP is the restoration of „wholesomeness‟ of all rivers of the Ganga River Basin, with particular emphasis on the main-stem of Ganga. Restoring wholesomeness of rivers means ensuring the sanctity of the fundamental aspects of the river system such as (i) continuous flow (Aivarla Qaara) and most importantly maintenance of connectivity in the river systems, (ii) un-polluted flow (inama-la Qaara), and (iii) maintenance of river as geological as well as ecological entities. The above objective must be achieved, notwithstanding the pressures arising from increasing population, urbanization, industrial and agricultural activities in the Ganga River Basin. With this background, following four broad objectives in context of the preparation of GRB EMP may be set: (i) environmental flows, as determined through thorough analysis of geological, ecological, socio-economic and cultural functions of the river systems, shall be maintained in all tributaries and main stem of the Ganga River in all seasons and under all circumstances, (ii) river water quality in all tributaries and main stem of the Ganga River shall be consistent with geological, ecological, socio-economic and cultural functions of the river system, (iii) excess water available in the river system over and above environmental flows will be used judiciously, equitably and effectively for sustainable development, (iv) all existing/ongoing/planned anthropogenic activities in the Ganga River Basin involving hydroelectric power generation, water (both quantity and quality), sediment, flood plain and riverbank management shall be reviewed in a transparent manner and modified/implemented after achieving broad consensus among all stakeholders. It is envisaged that GRB EMP will suggest policy frameworks for a broad range of activities concerning hydroelectric power generation, water, sediment, flood-plain and river-bank management in the Ganga River Basin. These activities may concern and include, but not limited to (i) reducing river water pollution from domestic and industrial wastes and long-term surveillance of river water and sediment quality, (ii) maintenance of environmental flows in rivers of the Ganga River Basin and storage (instream/off-stream and surface/sub-surface) of excess water in the Ganga River Basin, (iii) use of stored water and reuse of treated wastewater for various purposes including irrigation and groundwater recharge, (iv) flood plain management including issues concerned with livelihood issues of people dependent on fishing and farming on river flood-plains, (v) riverbank management including livelihood issues of people directly dependent on the river for survival, (vi) management of sediment transport including issues concerning the checking of soil erosion and riverbank erosion, (vii) 15 IGCP 582: IIT Kanpur, January 2012 modification/ implementation of existing/ongoing/planned anthropogenic activities involving hydroelectric power generation, water (both quantity and quality), sediment, flood plain and riverbank management in a scientific and transparent manner after achieving broad consensus, and (viii) promulgation of a „Ganga River Basin Act” with a view of making National Ganga River Basin Authority (NGRBA) the nodal agency for long-term implementation of the GRB EMP. Conceptual Framework: A river basin may be viewed and modeled as a tree (e.g. Banyan Tree as shown in the adjacent picture) having numerous leaves (representing numerous watersheds) and many small and large branches (representing small streams/minor and major tributaries). It is important to realize that health of each and every watershed is paramount to the maintenance of the health of streams/ tributaries, as also the health of the main stem of the river in the basin. Hence a bottomup approach of conserving watersheds, streams and tributaries, and wetlands to the main stem of the river is essential. The Ganga River Basin (GRB) as conceptualized above is a multifaceted system and requires multi-disciplinary and interdisciplinary approach. For integrated management of GRB several aspects need to be considered. The work on preparation of the GRB EMP has been broadly undertaken through various broad themes including (i) environmental quality and pollution, (ii) water resources management, (iii) fluvial geomorphology, (iv) ecology and biodiversity, (v) socio-economic and socio-cultural, (vi) policy, law and governance, (vii) geo-spatial data base management, and (viii)communication. Guiding Principles: In order to prepare GRB EMP with abovementioned vision and conceptual framework, principles that guide include: (i) application of modern science and new technologies but with traditional wisdom (&aana Qaara + jana &aana), (ii) application of precautionary principles wherever knowledge gaps and uncertainties exist, (iii) use of multi-disciplinary inputs with the caution that only “Experts” and “Some Influential Stakeholders” do not drive the process, (iv) starting from smaller watersheds and building up in a nested manner to the higher sub-basin level, and then to the basin level, (v) keep flexibility to cater to future needs and changing contexts, (vi) clearly articulating choices and the trade-off involved – environmental flows, irrigation, hydro power, domestic, commercial and industrial needs or in other words environmental, social, cultural, economic, and financial criteria must be given appropriate weightages, (vii) necessity of treating parts/portions of basin with heavy interventions (highly altered/modified) differently from portions with low intervention intensity (near pristine), (viii) avoiding and eliminating pollution through all direct and visible anthropogenic activities (zero tolerance or concept of zero discharge), (ix) considering surface and ground water together; exploring all possible means of storing water keeping continuous flow, and longitudinal, lateral and vertical connectivity of the rivers, (x) protecting existing water uses but taking care that existing inequities are not perpetuated, (xi) creating broad public acceptance of the plan (local bodies, state assemblies and parliament to debate and approve), (xii) creating of structures to monitor and regulate the implementation (nested governance; central and state government to serve as mentor and local communities assigned roles, responsibilities and rights on water considering compromises by/needs of upstream/downstream communities. 16 IGCP 582: IIT Kanpur, January 2012 ECOSYSTEM BASED MANAGEMENT OF RIVERS: ARE WE MAKING ANY EFFORTS TOWARDS IT? Parineeta Dandekar, Himanshu Thakkar, South Asia Network on Dams, Rivers and People, India Ecosystem based management of rivers implies planning and implementing activities through an ecosystems approach. It would include evaluating all the social, ecological and economic services that a river flowing with freshwater in its natural or close to natural state provides. Such evaluation will have to part of the planning, decision making processes including Environment Impact Assessments, Cost Benefit Analysis, and Options Assessment with life cycle approach. This will have to happen in a participatory way, with decisive participation by the communities living along the rivers at all stages. The Recommendations of the World Commission on Dams provide a good framework for this. As one of the steps in that direction, world over, river restoration works are being planned and implemented with stakeholder participation to restore rivers to objective states in order to optimise benefits enjoyed by the community from the riverine ecosystem. In response to the growing appreciation to the value of ecosystem services like biodiversity, fisheries, water purification, balanced geomorphology, balanced hydrological regimes, pollutant trapping, bank stabilisation, etc., systems are being developed in many countries. The example of New York City receiving pure water from naturally protected Catskill mountain ranges and watersheds at a much lower price as compared to conventional water treatment plants is well known. Providing rivers its space to flow in European rivers and decommissioning of dams in US and other countries are some other examples. Through various studies, it is proved that riparian areas are efficient at processing organic matter, sediments and sediment bound pollutants, they regulate microclimates, remove phosphorus and nitrogen containing compounds, reduce coliform and pathogens and transform animal waste and chemical fertiliser into less harmful substances. (Riley, 2008, Putting A Price On Riparian Corridors As Water Treatment Facilities) However river management examples from India prove that we are completely disregarding ecosystem based management of rivers. On the other hand, infrastructure based management of rivers and waterways are the only governing mindset. We are damming, diverting, channelizing and embanking rivers in the name of development, beautification and flood management, we do not have laws, institutions or mechanisms in place to protect the flowing rivers and its services, riparian corridors or floodplains of the river which perform multiple functions like flood mitigation, water supply, water purification, biodiversity protection, etc., we are not exploring or using bioremediation methods for treating our unmanageable point and non point sewage and effluents. Ecosystem based management of rivers is not being considered seriously by water resources establishment, any River Action Plans or schemes for River Restoration funded under projects like JNNURM. The paper at hand tries to explore the governance and management gaps that exist in India which currently are extremely counterproductive to any sort of ecosystem-based management of rivers. 17 IGCP 582: IIT Kanpur, January 2012 WATER QUALITY AND ECOSYSTEM MANAGEMENT OF GOMTI RIVER: A CATCHMENT PLANNING APPROACH Venkatesh Dutta+ and Ravindra Kumar Srivastava* + School of Public Policy, University of Maryland, College Park, MD, US & School for Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow 226 025, India *State Water Resources Agency (SWaRA), Lucknow, India This paper is the outcome of an expedition study carried out in March-April 2011 on Gomti River which is a major tributary of river Ganga, one of the largest tropical rivers in the world. We focus on assessing long-term, direct impacts of human-induced change and climate variability on the river-system and outline an ecosystem-based management using catchment planning approach. We use older satellite images (LANDSAT 1978) and compare them with the recent satellite maps (LISS III 2008 & 2011) to study changes in the land use of the basin. Simultaneously a water quality assessment is also carried out at 30 different segments of the river for major quality parameters. We notice that, there has been severe reduction in forest cover and wetlands in the entire Gomti basin due to rapid land use change and increasing demand of pristine land from urbanization. This has affected flow of water in Gomti River adversely as most of the tributaries originate from water bodies or forests and reduction in their density has caused reduction in water availability in the river. Except Pilibhit and Kheri, all the districts falling under the basin are deficient in forest cover. Secondly, the result of sampling indicates that the quality of the water has deteriorated due to discharge of untreated wastewater from about 50 major drains in its entire course of 960 kms. We outline an ecosystem-based management using catchment planning approach suggesting measures for the conservation and improvement of the physical environment of the catchment including how land use changes in the eco-fragile areas can be minimized, how water should be apportioned the prioritized in the utilization and allocation to the different sectors, and finally, water quality standards which are to be enforced by the regulatory agencies. 18 IGCP 582: IIT Kanpur, January 2012 EVOLUTION OF TIDAL DOMAIN AS GEO-RESOURCE - A CASE STUDY OF CREEK SYSTEMS OF WESTERN SUNDERBANS Tapan K. Jana1, Sudipto Lahiri2, Amal K. Samadder3, Pranab K. Mitra4, Debasish Sengupta4 & Jyoti Prakash Kumar5 1 Geological Survey of India, Research & Analysis Division, 27, Jawaharlal Nehru Road, Kolkata 2 F-26/2 Karunamoyee, Salt lake, Kolkata - 700 091 3 514, Baishnabghata Patuli, Flat No. 7, Kokata - 700 094 4 Geological Survey of India, Geodata Centre, Marine & Coastal Studies Division, BlockDK6,Sector-II, Salt Lake, Kolkata - 700091 5 32, R.K. Street, Uttarpara, Hooghly Historically and traditionally landform units of tidal regime of Sunderbans have collectively been looked upon as resources for both survival and livelihood. With the change in hydraulic regime of the tidal system over last several centuries, and as follow up, changes in creek systems, the quality of the micro landform units and pattern of their utilization have witnessed major transformations. The understanding of the evolution in geo-resources would necessitate closer appreciation of the tidal dynamics and of the tidal landforms of the creek systems. With deterioration of trunk channel of the Ganga River, the downstream drainage channels and tidal creeks were left to be flushed with tidal flows only. Thus the creek systems, many of which were earlier having sufficient draught for large vessels to ply, had been abandoned and, same fate followed for some of the ancient habitations. The settlement policy in Sunderbans during British period ushered in major changes in land use practices and the process of building up of land in the inter tidal marshes by tideborne silts was arrested. The creeks further witnessed shallowing of channel beds, modification of channel bars and tidal flats. The geo-resources of creeks and associated landforms went through modifications partly due to anthropogenic interference and because of natural instability of the tracts. The recent surveys (2005-09) of Geological Survey of India in parts of western Sunderbans indicate that many of the creeks and minor cross channels show rapid deterioration in the north; while outfall points of major creeks show extensive modification in channel morphology. Various in-channel landforms including channel bed geometry, tidal flats, mid channel shoals and bars and creek margins have been studied extensively during the survey and their resource potentials have been assessed. Since the trends of changes in tidal domain is complex in nature, flexibility in landform-resource utilization and principle of sequential land use practice should be incorporated in perspective planning of geo-resources for conservation and development of this fragile domain at land-sea interface. The present study aims at bringing together geological history of the trunk river (Bhagirathi) and the evolution of creek systems of Sunderbans into a broad framework of tidal geo-resource potentials- a step toward this objective. 19 IGCP 582: IIT Kanpur, January 2012 SURFACE AND GROUNDWATER INTERACTION IN YAMUNA RIVER FLOOD PLAIN AT AGRA ENDANGERING THE SAFETY OF TAJ MAHAL Ravindra Kumar Drinking Water Expert, State Water Resources Agency, Lucknow, U.P., India ravindra53@yahoo.co.in Yamuna has been engineered for the past two centuries, shaped to serve humanity by controlling flows and the beds. It is assumed that economic development will shape the river ecology by river front development, ensuring ecological flows and taking pollution abatement measures. In Delhi, the Yamuna is being increasingly modified and its riverbed is encroached on by urbanization. In Agra, Taj Mahal –a symbol of an emperor‟s extraordinary love for his wife and an engineering marvel of archeology, attracts around 1.4 million visitors annually of which about one-fourth are foreigners, is now tilting, the reason given is sal wood in foundation have become brittle and are disintegrating due to want of water in river Yamuna. Hon‟ble Supreme Court of India by order dated 14-10-2011 in WP (Civil) 13381 of 1984 has asked to file the response from authority concern in Central and State governments. In this paper an attempt is made to understand river water interaction with groundwater in the city area of Agra along Yamuna river flood plain on both sides of the river to infer the impact of lean flows in river and groundwater pumping in overall lowering of water table in foundations of Taj Mahal that is forecasted, if this situation persists, a serious damage is likely to be caused to minerate. Based on the hydraulic analysis of 30 years (1978-2007) ten-daily average flow data of Yamuna river at Agra, it has been found that tendaily average minimum flow during lean flow months (March to June) ranges between 2.15 to 6.75 m3/s and falling in 19 out of 30 years. In recent past after 1997 onwards due to high floods experienced by Yamuna and Courts activism ten-daily average flow has been found about 9 to 12 m3/s, except for the year April,2002, whereas a maximum ten-daily average of 15.73 m3/s was observed in May 1999. The mean monthly low flow is above threshold figure of 10 m3/s, as decided by Hon‟ble SC. Thus it can be concluded that lean flow months fulfill the statuary threshold value in Yamuna at Agra after 1997, except in April 2001. But depth to groundwater pre and post monsoon (2007 to 2010) map of Agra city area have gone down from 10 mbgl to 33.34 mbgl during pre monsoon in Kalal Khera. The piezometeres at Commisoner‟s office, DD Tourism office fall in between minimum 23.41 m to a maximum 27.76 mbgl. The piezometrers on trans river (opposite to Taj Mahal side) show groundwater table in between 15.94 to 17.56 mbgl in Sahadra and 22.50 to 25.55 mbgl in Dhandu Pura. The post monsoon water levels are in general about 1 to 2 m up, meaning thereby that rainfall recharge and recharge due to floods form about 1 to 2 m only. The Taj Mahal is hardly 100 m away from the center line of the river Yamuna. This phenomenon of increasing decline in water table is the result of excessive groundwater pumping to meet the developmental needs of the City. Government of Uttar Pradesh is considering the proposal of constructing a small weir downstream of Taj Mahal to manage the additional water required for the safety of the structure. But if pumping continues as usual, this option may offer less environmental benefits. The pristine status of a river-the „ideal‟ is a flawed idea, it seems now. But irony is the development has not answered the question of river ecology. On the basis of our hydraulic and hydro-geologic analysis of Yamuna flood plain at Agra and confirmation by isotopic studies of Yamuna at Delhi by NIH, a parallel may be drawn in the results. Further, a long term investigation is required for confirmation of the hypothesis drawn for geo-morphological setting of Agra. 20 IGCP 582: IIT Kanpur, January 2012 QUALITATIVE ASSESSMENT OF PARAMETERS CONTROLLING GROUNDWATER QUALITY IN SABARMATI RIVER BASIN Kumari Rina1, C. K. Singh1, 2, R. P. Singh1, Vikas Kamal1, Neha Singh1, Saumitra Mukherjee1 1 Remote Sensing Application Lab, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110067, INDIA 2 Department of Natural Resources, TERI University, New Delhi-110070 Email: saumitramukherjee3@gmail.com Due to scarcity of surface water and uncertainty of monsoon, depletion of groundwater and deterioration of its quality has become a prime concern in semi arid/arid region. Along with it anthropogenic influences, such as change in cropping pattern and high industrial activities are likely to make groundwater more vulnerable qualitatively. One such area is a part of Sabarmati River basin of Gujarat, situated in the west coast of India, dominated by intense growth of agricultural and industrial activities. The average per capita water availability in the Sabarmati basin is 324m3 which is the lowest in India (1991 census). Similarly, the average annual water availability per hectare of cultivable area is 2455m 3 which is second lowest in India. Factors influencing the groundwater hydrochemistry in preand post-monsoon season were evaluated. Groundwater samples were collected from 5 km X 5 km grids on the basis of spectral signature of vegetation and soil, observed on satellite image. Conventional graphical plots, Piper plots were used to decipher the hydrogeochemical process occurring in the study area. USSL diagram, % sodium and SAR were used to verify the suitability of groundwater for irrigation. It was observed that leaching of wastes disposed from anthropogenic activities and agrichemicals is the major factor in addition to the natural processes such as weathering, dissolution and ion-exchange that govern the hydrogeochemistry of groundwater in the study area. Control of indiscriminate and unplanned exploitation of groundwater, application of fertilizers and disposal of industrial wastes in the affected areas can possibly ensure groundwater protection from further pollution and depletion. REMOTE SENSING AND GIS BASED STUDY OF DAM INDUCED GEOMORPHIC CHANGES IN THE GANGES IN THE HIMALAYAS Vikas Kamal, R. P. Singh, Neha Singh, Rina Kumari, Rajesh Kumar, Ritesh Sipolya, Javed Mallick, Saumitra Mukherjee* School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110067 *email: saumitramukherjee3@gmail.com In the Northern mountainous part of the Ganga basin, Tehri dam is a major hydroelectricity project. Along with this many other smaller dams have come up in the last decade. Theses dams have reshaped the channel belt of the Ganges in terms of depositional and erosional features. Further they have changed the flow regime to an entirely different mode. Remote sensing and GIS (Geographic Information System) was used to study these features in detail for different time periods. A comparative analysis is presented through figures and images of such changes. Besides disturbance zones are presented from low to high ranges. Areas of significant changes are discussed in detail. Valley shapes with respect to land use and land cover in the region are focused. Past references of natural disasters have also been quoted to correlate with fluvial geomorphology of the Ganges in the Himalayas. SRTM DEM of 90m resolution revealed the approximate stream power of the river through a meticulous analysis. High resolution LISS IV PAN merged and Google Earth images were 21 IGCP 582: IIT Kanpur, January 2012 used to study riffles and pools in the stretch. Though the terrain is mountainous, but the inchannel features develop here because of extensively meandering river course along this stretch that has been mapped in GIS platform (Fig. 1). Fig1. Mountainous stretch of the Ganges with an inset showing in-channel features HUMAN IMPACT ON RIVER SYSTEM TO CLIMATE CHANGE Dr.Aruna Kumari & others VSSD College, Kanpur Most water problems are in the semi-arid and coastal regions of the world, including parts of the U.S. The demands of expanding human populations, necessitating irrigation systems and industrial requirements, which led to the depleting underground aquifers that water is intruding into them along coastal areas of the U.S., Israel, Syria, and the Arabian Gulf states. In inland areas, porous rocks and sediments are compacting when drained of water, causing surface subsidence problems; this subsidence is already a serious problem in Texas, Florida, and California. The world is also experiencing a steady decline in water quality and availability. About 75 percent of the world‟s rural population and 20 percent of its urban population have no ready access to uncontaminated water. In many regions, including parts of the U.S., water supplies are contaminated with toxic chemicals and nitrates. Waterborne disease debilitates one-third of humanity and kills 10 million people a year. During the 1980s and early ‟90s, the world improved water quality by reducing particulate matter and toxic chemicals, such as lead, but the problems of sulfur dioxide and nitrous oxides, the precursors of acid deposition, still remain. As we can see the situation of Ganga River in our country, is not the only river which is destroyed. Yamuna and Gomti rivers are also destroyed by humans. Due to these global warming, soil erosion, acid rain are occurring faster. 22 IGCP 582: IIT Kanpur, January 2012 IMPACT OF HUMAN ACTIVITIES GOMTI RIVER – LUCKNOW Dr. Sangeeta Sachan, Shurti Sharma, Shalini Tripathi Department of Geography, University of Lucknow, Lucknow Email-trishala.hina1992@gmail.com, drsangeetsachan@gmail.com World sever; drains are the main source of water polluting especially for river flowing within the city. There drains generally carry industrial effluent, domestic water, sewerage and medicinal water results in pooring the water quality.Among drains, the Kukrial drain (mind of the city) is the highest pollutied draun while – Gaught the least (upstream).The higher level of pollutants polluting the water quality of river Gomti, disturbing the ecology of river and affecting human health directly and indirectly. 23 IGCP 582: IIT Kanpur, January 2012 RIVER (DIS)CONNECTIVITY IN KOSI RIVER BASIN AND ITS TEMPORAL AND SPATIAL DYNAMICS Rakesh Kumar1, Kumar Gaurav2, Vikrant Jain1, Rajiv Sinha2 ¹ Department of Geology, University of Delhi, Delhi - 110007, INDIA ²Department of Civil Engineering, Indian Institute of Technology, Kanpur (UP), INDIA Email: rakesh.geology@gmail.com; gauraviirs@gmail.com; vikrantgeo@gmail.com; rsinha@iitk.ac.in Geomorphic connectivity in a fluvial landscape is an important geomorphic concept and governs channel processes, river response, sediment dynamics and pattern of natural hazards in a river basin. Connectivity is controlled by different types of barrier, buffer and blankets, which may be natural or anthropogenically controlled. A (dis)connectivity analysis has been carried out over the Kosi megafan to analyse anthropogenic disturbance on the hydrological and sedimentological connectivity in the basin. Connectivity is defined either on the basis of physical contact (structural connectivity) or on the basis of material transfer (functional connectivity) (Jain and Sinha, 2011). In the current analysis the (dis)connectivity in the river basin on the basis of drainage network has been quantified and a connectivity index has been proposed on the basis of material transfer and physical connectedness. Further, spatial and temporal dynamics in connectivity index and its influence on channel processes and water logging problems in the area has been analysed in detail. A detailed mapping of drainage network and all embankments related to road and rail network has been carried out for the entire Kosi megafan. The study area has been divided into various grids of 10×10 km to analyse spatial variability while temporal variability was analysed through 1:50,000 scale Survey of India toposheets of 1983 and 1955. The intersection points between draiange network and embankment has been inspected in the field and these points are classified into connected, partially connected and disconnected intersections. Densities of the intersected point were high in the 1955 whereas in 1983 it‟s less as compare to earlier model. The maximum intersection points lies near the Saharsa District (lies nearby Kosi Main channel) while the minimum intersection points counts in the district of Purnia (lies away from the channel). (Dis)connectivity in the Kosi megafan is controlling the sediment dispersion configuration over the megafan, which leads to the water logging in the basin. The localized depositions of suspended sediments and water storage due to longitudinal disconnectivity have made the channel shallower and have caused overbank flooding and waterlogging condition. These changes in river processes will also disturb the riverine ecosystem over the megafan surface, which needs to be studied in detail. Further, role of spatial depositional pattern on elevation variability will also be studied to analyse correlation between the avulsion pattern and the geomorphic connectivity. Currently, no understanding is available on the processes responsible for downstream avulsion points on the Kosi megafan area. 24 IGCP 582: IIT Kanpur, January 2012 GEOMORPHIC RESPONSE OF A RIVER SYSTEM TO URBANIZATION, A STUDY FROMYAMUNA CHANNEL REACH AROUND DELHI NCR Parul Tyagi, Nupur Bawa, Vikrant Jain Department of Geology, Centre of Advanced Studies, University of Delhi, Delhi-7 Email:-parul.geo@gmail.com; nupur.geology@gmail.com; vjain@geology.du.ac.in Channel processes and morphology is one of the fundamental characteristics to analyze river health as morphological variability defines habitat for biodiversity of a river system. Any variability in channel processes and morphology will thus affect the whole ecosystem of a river system. In recent years, human induced disturbances have affected the natural flow of the river thus altering the associated processes, morphology and habitat. Among all the human interference, urbanization is considered to be a major obstruction to the natural flow of the river. Anthropogenic activity significantly alters different fluxes in channel and consequently changing channel condition and morphology. Thus understanding of the channel processes is a key to understand the variability in the system that has caused either by external factors or is a self-induced response of the system. A study was carried out to analyze the disturbance of Delhi NCR on the channel processes and morphology of a larger river system, i.e. the Yamuna River system. The Yamuna River at Delhi is characterized by 19418 km2 basin area and length of 131 km with average annual discharge of 478 m3 /s. The morphological mapping was carried out for the Yamuna reach around Delhi and upstream region using IRS LISS IV data. Yamuna reach of 131 km length was studied from Panipat to Kalindi Kunj area. The upstream 96 km reach from Panipat to Palla is not affected by urbanization while 35 km downstream reaches falls in the urbanized area. Using GIS software‟s, channel width, slope, bar area and channel area were calculated for the downstream variability. This variability was used to analyze dominant processes upstream of the urbanized Delhi Yamuna reach. Reach scale slope variability and bar connectivity is a dominant factor controlling the erosion and deposition processes and resultant channel morphology along the 96 km reach between Panipat to Palla. Similar trend has been observed in terms of cross sectional variability. Channel reaches with low slope are also having wider cross sections whereas reaches with steeper slope are of narrow cross sectional width. Channel reach downstream of Panipat- Palla stretch falls into the stressful urbanized environment where the normal trend is expected to be influenced by local inputs from the surrounding catchment. The outcome of observation for the downstream 35km urbanized stretch shows a diverging pattern. Slope variability does not have a significant control on channel processes, morphological behavior and cross sectional variability. Wider channel cross sections are not concurrent with reaches of considerable deposition. Wazirabad bridge at 15 km downstream of Palla is a major obstruction which along with other features like canals and tributary (nala) contribution have a major control on channel morphology and processes in downstream reaches. A preliminary study shows a significant deviation in controlling parameters due to urbanization impact in Delhi NCR. 25 IGCP 582: IIT Kanpur, January 2012 HISTORICAL POLLUTION TRENDS IN TAMIRAPARANI RIVER BASIN, SOUTH INDIA R. Arthur James*1, R. Purvaja2 and R. Ramesh2 * Department of Marine ScienceBharathidasan University, Tiruchirapalli – 620 024 INDIA 2 Institute for Ocean ManagementAnna University, Chennai – 600 025 INDIA Email: james.msbdu@gmail.com 1 This paper highlights the pollution history and their recent accumulation rates from a perennial smaller river basin. Surficial sediments were used to determine the sediment chemistry and environmental enrichment factor for pollution purpose; because they provide a long term record and more convincing information of what rivers do as a whole. Textural, mineralogical and chemical studies on riverine sediments offer an insight into the river basin provenance and the effect of transport on the original relationship in the geological formations. The Tamirapani river is one of the perennial smaller river in south India, lies between latitude 8ο 20‟ N and 9 ο 13‟ N and longitude 77 ο 10‟ E and 78 ο 10‟ E. Detailed sediment chemistry on surficial and core samples were carried out in association with sediment accumulation rates using Pb210 and Ra 226 methods. The sediment accumulation rates varying from 5 to 12 mm yr-1 and comparison was made between polluted and unpolluted region of the study area. The sedimentation rates were high in downstream region and were relatively constant in midstream due to damming effect. The study also proved, estuary region is filled with freshly deposited sediments which is of recent origin by the river. Human activities such as agriculture, deforestation, grazing, and dam construction across the river influences the sediment load. The estuarine region did not show any clear exponential radioactive decay mainly due to bioturbation within the system. HYDRO-GEOCHEMICAL PROCESSES AND QUALITY ASSESSMENT OF SURFACE, SUB-SURFACE AND MINE WATER RESOURCES IN THE UPPER CATCHMENT OF DAMODAR RIVER BASIN, INDIA Abhay Kumar Singh Central Institute of Mining and Fuel Research(Council of Scientific & Industrial Research) Barwa Road, Dhanbad - 826 015, India Email: singhak.cimfr@gmail.com The water bodies are continuously subjected to a dynamic state of change with respect to lithological characteristics and geo-climatic condition. This dynamic balance in the aquatic system is upset by human activities, resulting in pollution. Mining is one of the major activities causing water pollution. Damage to quality and quantity of surface water and ground water due to dumping of overburden (OB) and spoils or spreading of OB through rolling and washing may cause the chemical pollution. Damodar River Basin is known for its coal deposition and commonly referred as „the storehouse of Indian coal‟. Damodar River originates from the Khamerpet Hill, near Palamu and flows through the cities Ramgarh, Bokaro, Dhanbad, Asansol, Durgapur, Bardwan and Hawrah, before ultimately joining the lower Ganga (Hooghly estuary) at Shayampur. The upper catchments of the Damodar River basin are actively associated with mining activities for more than a century. More than 500 coalmines including famous Jharia coalfield, which produce prime coking coal, are located in the basin area. Besides, active open cast and undergrounds mine, there are number of abundant coalmines and associated dormant overburden dumps. The presence of active and abundant coal mines, overburden dumps, thermal power plants, coal washeries, coking coal plants and other coal based industries including refractories, steel, fertilizer and cement plants poses serious threats 26 IGCP 582: IIT Kanpur, January 2012 to the quality of available water resource of the area. In the present study, detail investigation of water chemistry of surface, subsurface and mine water of the upper catchment of Daomodar River basin has been carried out to know the source of the dissolved components of waters, geochemical factors controlling the water composition and the suitability of water for domestic, agricultural and industrial uses. The analytical results show that Ca, Mg, and HCO3 dominate the chemical composition of the water chemistry. However, in the mine water and water samples collected from mining areas having high concentration of sulphate and it replace the dominance of bicarbonate in the anionic abundance. Water chemistry of the study area strongly reflects the dominance of continental weathering aided by anthropogenic activities. Higher concentration of SO4, Cl and TDS in some samples indicates mining and anthropogenic impact on water quality. The high contribution of (Ca+Mg) to the total cations, relatively high (Na+K)/TZ+ ratio and low equivalent ratio of (Ca+Mg)/(Na+K) suggests combined influence of carbonate and silicate weathering. The higher value of C-ratio for most of the surface and subsurface water signify that carbonic acid weathering is the major proton producer in these waters. However, the low C-ratio for the mine water (average 0.22) and the water collected near the coal mining areas suggests that either sulphide oxidation and/or coupled reactions (involving both carbonic acid weathering and sulphide oxidation) control the solute acquisition processes in the mining areas. In general, the quality of the ground water is suitable for domestic uses with some exception. The calculated values of SAR, RSC and sodium percentage indicate good to permissible quality of water for irrigation uses. However, the high salinity, %Na, Mg-hazard, and RSC values at certain sites restrict its suitability for agricultural purposes. CHANGE IN SOCIO ECONOMIC VULNERABILITY OF THE PEOPLE EX-ANTE AND EX-POST OF A DEVELOPMENT PROJECT Ajay K Katuri Faculty of Planning and Public Policy, Center for Environmental Planning and Technology (CEPT) University, KL Campus, University Road, Navarangpura, Ahmedabad, Gujarat - 380 009 E-mail: ajay.katuri@cept.ac.in Sabarmati River flows through Ahmedabad and bifurcates the city into older (eastern) and rather modern west. The city had been facing recurrent floods because of seasonal runoff in the river from 18550sqkm of catchment. In the earlier part of the study, a SOBEK 2-D simulation was carried out pre and post implementation of a river front development project in Ahmedabad. For assessment of risk as a consequence of a development project, we need a detailed vulnerability assessment (Turner et al. n.d.; Mohanty n.d.; Elbers & Gunning n.d.; Boruff et al. 2009; Attzs 2008; Gaiha & Imai 2008; Revi 2007; Füssel 2007; de Kruijk & Rutten 2007; Birkmann 2007; Calvo & Dercon 2005; Makoka & Kaplan 2005; Dwyer et al. 2004; Kamanou & Morduch 2004; Susan L. Cutter 2003; Westen 2006). This paper presents a methodology to assess the vulnerability of the exposed population. Population information from Census 2001 was used for disaggregation at building level. Population disaggregation has been based on various indicators, viz., building density (DU/sqkm), population density (people/sqkm), Floor Space Index, Traffic Analysis Zone, floating population, day-time and night-time population densities, etc. An overlay of the hazard maps with the vulnerability information produces the risk information both in terms of buildings as well as population. This analysis will be used for many ex-ante analysis of impact of development projects. 27 IGCP 582: IIT Kanpur, January 2012 VALLEY MARGIN AND ACTIVE FLOODPLAIN OF RIVER GANGA: DEFINING “RIVER SPACE” S. Ahmad, Lipi Basu, H. Mohanta and R. Sinha Engineering Geosciences Group, Department of Civil Engineering Indian Institute of Technology Kanpur, Kanpur 208016, India The Ganga River, 2525 km long, is one of the largest tropical river systems in the world. For a sustainable river management, it is important that the functionality of river valley and floodplain are recognized and delineated properly. A river must have „adequate space‟ to perform its myriad function. The river „valley‟ and „active floodplain‟ define that space for the river albeit with different functionality. Active floodplain is defined as an area on either side of a stream/river which is flooded on a periodic basis (~2.33 years). A river valley is a wider and more extensive area which is primarily defined on the basis of a topographic break across the river. For large river systems such as the Ganga, remote sensing techniques provide a powerful approach due to their synoptic view and repetitive coverage for studying morphological characteristics of rivers and their dynamics over time. This paper is focused at mapping and delineating the extent of valley margin and active floodplain in parts of the Ganga River as a part of the Ganga River Basin Management Plan (GRBMP). Landsat 4-5 TM and IRS P6 AWiFS satellite data of pre-post monsoon of 200910 were processed to generate tasseled cap and NDWI which helped to delineate the active floodplain. Both these images contain information about the moisture content which along with other floodplain features was used to map the active floodplain along the river. The valley margin was delineated using the cross profiles across the river using the SRTM digital elevation data acquired in 2000. The valley margin was marked using the topographic break on both sides of the river. In the mountainous reaches from Gomukh to Rishikesh, the Ganga valley is much incised (<0.5 km) and there is no floodplain development due to steep valley walls. The river debauches in the plains near Haridwar and forms a wide active floodplain (~15 km) which reduces to ~5 km at Narora barrage. Downstream of Narora, a major river, the Ramganga, joins the Ganga and a wide (~12 km) floodplain has formed near the confluence. The narrowest parts of active floodplain (~1 km) and valley margin (~9 km) are present from Fatehpur to Sirathu in the plains area. Near Allahabad, active floodplain and valley margin are highly asymmetric showing alternate widening and narrowing and the active floodplain nearly coincides with valley margin. Further downstream from Dheena to Farakka, both active floodplain (~26 km) and valley (~30 km) are wide throughout and nearly coincide except in a few reaches. The mapping of valley margin and geomorphic features in the active floodplain along the Ganga River shows significant diversity in terms of valley width and geomorphic features in different reaches of the river. These differences have important implications for water resource management and ecological restoration. The stretches with wide valleys and active floodplains could provide sites for creating artificial recharge sites keeping in view the present-day landuse. The channel-belt and floodplain features should provide important insights to the possible habitats for aquatic and land biota. These maps should be integrated with the present distribution of biodiversity along the river and the causal factors for their abundance/absence can be ascertained. In terms of hydrology, the geomorphic features such as the variety of bars are suggestive 28 IGCP 582: IIT Kanpur, January 2012 of river processes which would ultimately relate to the hydrological regime and would provide an important input for E-flow assessment. ECO-GEOMORPHOLOGY OF GANGA RIVER BASIN BASED ON INPUTS FROM SATELLITE DATA: IMPLICATIONS FOR RIVER MANAGEMENT Haridas Mohanta, S. Ahmad, Lipi Basu, R.P. Mathur and R. Sinha Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur A sustainable river management plan requires basic inputs from geomorphology, ecology and hydrology. Eco-geomorphology is a tool which interrelates the three disciplines and provides a suitable platform for river management. The Ganga River in its long stretch from Gangotri to Gangasagar shows significant geomorphic diversity as a function of topography (slope), precipitation (discharge regime) and sediment transport (tectonic setting and discharge). Apart from regional scale changes in river morphology, the river shows a conspicuous change in reach-scale morphology as well as valley width, floodplain width, channel form, and floodplain features. These changes are in turn reflected in the change of habitat in the river ecosystem as well as in other parameters of hydrology. This paper presents some results on the geomorphic mapping of parts of the Ganga River (Haridwar-Kanpur stretch) using satellite remote sensing data to provide inputs for developing an ecosystem-based management plan for the river. Landsat TM, pre-monsoon (April 2009-10) data was used for mapping different fluvial geomorphologic features in parts of the Ganga plains downstream of Haridwar covering the stretch up to Kanpur. Geomorphic mapping was taken up for channel belt and active floodplain using enhanced digital images in conjunction with Google Earth images and SRTM digital elevation data. Field observations were undertaken to validate geomorphic features. Some of the important features mapped in the channel belt included mid channel bars, side bars, point bars, alluvial islands and abandoned braid bars. Similarly, flood channels, meander scrolls, meander cut offs, dry channels are the main features in the active floodplain. Downstream of Haridwar, the Ganga river is significantly braided with frequent mid channel bars and alluvial islands and very wide floodplain on both sides of the river. The allivial islands do not show up downstream of Garhmukteshwar and the floodplain is also confined to the left bank only downstream of this point upto Narora. Geomorphologically, this stretch is characterized by an aggradational regime. Strong bends and meanders on either side of the river suggest a significant river dynamics and a dominant estward or westward shift is ovserved in different reaches. Ecological data reveal that this stretch is dominated by Phytoplankton (diatoms and green algae), Zooplanktons (Rotifers and Cladocera), Phytobenthos-(Pediastrum and Scenedesmus), Zoobenthos (Trichoptera - Caddish fly and Beetle - Coleoptera). The dominant Fishes are Major Carps and Minor Carps. Among the higher vertebrates, Turtles and Ghariyals are common. Betweeen Narora and Kannauj, the river valley widens but the floodplain remains narrow and patchy. Two important tributaries, the Ramganga and the Garra join from the northern side and the river Kali from the southern side around Kannauj.The river is highly braided but with significant sinuosity in several reaches. As a result, abandoned braid bars form a significant geomorphic feature followed by lateral bars. A number of abandoned channels are mapped which bound the abandoned braid bars and therefore representing the secondary channels of the Ganga. Geomorphologically, this stretch is characterized by an aggradational regime and a 29 IGCP 582: IIT Kanpur, January 2012 major confluence zone between the Ganga and Ramganga. The confluence zone has been dynamic at historical-scale as reported in the literature and a shift upto 10-12 km has been documented. In the stretch between Kannauj and Kanpur, The Ganga river flows along the southern margin of the valley and is incised in most reaches with a cliff line varying in height from 10-15 meters. As a result, a wide floodplain runs along the northern bank and very narrow floodplain along the southern bank. The channel is multi-thread with frequent and large mid-channel bars and infrequent lateral bars. Abundant meander cutoffs, scrolls and abandoned meander loop in the active floodplain on the northern side suggests that the river has been gradually shifting towards the south. The presence of an abandoned meander loop upstream of Kanpur is conspicuous because of which the valley width suddenly widens. Geomorphologically, this stretch is characterized by a degradational regime as evidenced from high cliff line all along the right bank. Strong bends and meanders suggest a significant river dynamics and a dominant southward movement is apparent. Ecologically, the entire stretch between Narora and Kanpur is dominated by Phytoplanktons (diatoms/green algae); Zooplanktons are characterized by Protozoans, Rotifers and Crustaceans). Among the fishes, Indian major Carps are 40-50% and Cat fishes are 10-15% as estimated from their catch; Forage and other fishes are also found; Among the higher vertebrates, soft/hard shelled turtles are present, Ghariyals are very rare/scarce and dolphins are spotted. The mid channel bars, lateral bars, pointbars , abandoned braid bars and the active floodplain provide suitable habitats for aquatic and land biota.Turtles, Ghariyals and Dolphins generally use the river bank (i.e. basically the active floodplain,bars) for breeding. The understanding of river morphology provides important insights to understand the linkage between geomorphology and river ecology. Basic parameters of ecology such as habitat (riffles and pools), substrate (rock, boulder, gravel, sand), physical conditions (obstruction, abstraction), and nutritional status are controlled by geomorphology. For example, pools are the important habitats for the fishes as they can derive their required nutrients and substrates from it. In the river bank under the boulders stoneflies occur.These flies are taken as food for the fishes. Similarly, the soft sand beds of the channel provide suitable place for the breeding of the fishes. Hence, these boulders and soft sands create a link to the ecological distribution of fishes. 30 IGCP 582: IIT Kanpur, January 2012 Session III River dynamics and River hazards 31 IGCP 582: IIT Kanpur, January 2012 UNDERSTANDING THE FLUVIAL PROCESSES OPERATING IN WESTERN GANGA DELTA Kalyan Rudra West Bengal Pollution Control Board The Ganga delta, sometimes also known as Ganga-Brahmaputra delta, is the largest of the world. The triangular tract between two marginal distributaries of the Ganga and the Bay of Bengal covers an area of 57506 km2 and continues to grow southward under the water. The sediment influx into the western part of delta comes through the Ganga and its distributaries and also from uplands of Chotanagpur through seven major tributaries. The sub-aqueous part of delta, as seen in the recent satellite image, is forty-three times larger than its counterpart above mean sea level. The origin and evolution of the Holocene deltas of the world has been generally attributed to the plate movements, discharge in rivers and deposition of sediment load, subsidence of land and its consequent isostatic adjustments, tidal fluctuations, coastal current and changes in sea level. The formation of the thirty-six deltas over the world accelerated between 8500 to 6500 years BP due to a rise in sea level and post Pleistocene deceleration resulting in a large glacio-fluvial influx of sediment load. Both the apex of the Ganga delta and the southern front facing the sea are dynamic and have changed their locations within known historical period. It is an apparent paradox that in spite of receiving huge sediment load from an catchment area of more than one million square kilometer, the part of the delta lying above mean sea level is shrinking. This can be proved by comparing multi-dated maps with recent satellite image. In the process of delta building, the Ganga and its distributaries have the tendency to oscillate within their meander belts and avulse through distributaries. The presence many palaeo channels and ox-bow lakes in the active floodplain describe the history of river dynamics. The delta formation is a complex process where fluvial and marine land building processes are juxtaposed. While the fluvio-marine process dominates in the southern littoral tract, the fluvial process is active beyond northern tidal limit. The distributaries have the tendency to migrate laterally within their active floodplain. Since the Ganga or Padma incised its valley deeply, the distributaries like Bhagirathi, Bhairab- Jalangi and Mathabhanga-Churni do not get any headwater supply during lean months. It is only during the monsoon when the water in Ganga achieves a threshold level, the distributaries are activated. The alarming decay of channels in the western part of the delta and increasing dependence on engineering solutions to augment lean season flows and to combat flood and erosion, continue to imperil the delicate hydro-geomorphological balance of the Ganga delta. An attempt is made in this deliberation to conscientiously analyse fluvial processes operating in the western part of delta and also the impacts engineering approach to alter the natural processes. 32 IGCP 582: IIT Kanpur, January 2012 EXTREME FLOODS IN THE INDIAN SUBCONTINENT DURING THE 20TH CENTURY Vishwas S. Kale Department of Geography, University of Pune, Pune 411 007, India Email: vskale@unipune.ac.in Extreme rainfall and floods form an integral part the monsoon climate of the Indian subcontinent. The subcontinent is home to a number of large rivers that have a long history of flooding. It is generally believed that the incidences of extreme floods on these rivers and their tributaries may have changed in the past few decades on account of climate change associated with global warming. Concern is also being expressed regarding further increase in the flood risk in near future. The primary focus of this paper is on trend detection in large and extreme floods events on all the major rivers and some of their tributaries in the subcontinent. We investigated trends in 20 long-term annual maximum flood series, with an average length of 75 years. The long-term flood series data for fifteen large and moderate-sized rivers were analyzed. The rivers include Indus, Satluj, Ravi, Chenab, Jhelum, Ganga, Yamuna, Kosi, Brahmaputra, Mahanadi, Narmada, Tapi, Mahi, Godavari, Krishna and Kaveri. Although the flood series are characterized by substantial variability, the trend analyses of the flood series do not reveal any long-term tendency. However, a noteworthy absence of significant floods during the first four decades of the 20th century and a remarkable increase in extreme events during the post-1950s is demonstrated by flood series. Some of the recent extreme floods appear unusual within a historical context, but there is no upward trend in the occurrence of extreme floods across the subcontinent during the last century. HUMAN INDUCED RIVERBANK HAZARD IN KATHMANDU VALLEY, NEPAL * A.P. Gajurel1, D. Pathak1, G. B. Shrestha2 and S. K. Dwivedi3 Department of Geology, Tribhuvan University, Kathmandu, Nepal 2 Kathmandu Forestry College, Tribhuvan University, Balkumari, Kathmandu, Nepal 3 Department of Water Induced Disaster Prevention, Government of Nepal, Pulchok, Lalitpur * Email: apgajurel@wlink.com.np 1 Kathmandu valley is a largest intermontane basin occupying an approximate catchment area of 625 sq. km in the Himalaya. The surrounding mountains range in altitude up to 2,700 meter and average altitude of the valley floor is 1330 m. Basement of the valley is comprised by gneisses and meta-sedimentary rocks of Pre-Cambrian and Paleozoic age. It is filled with up to 600 m thick Plio-Pliestocene fluvio-lacustrine sediments. The valley is characterized by centripetal drainage pattern and the Bagmati River drains the entire valley through the south (Fig. 1). The average annual precipitation in the valley is around 1600 mm of rain. The study has been carried out in the river stretches of Kathmandu valley where Kathmandu, Bhaktapur and Lalitpur cities are rapidly growing since few years. Present research aims to understand the mechanism (natural versus human induced) of degradation of rivers in an area where rapid human encroachment to the natural regime of the rivers has been taking place during the modern fast rate of urbanization. Field observation, topographical map, aerial photographs and satellite imagery data were analyzed in GIS and riverbank hazard of the Kathmandu valley is assessed. Hazard problem is particularly associated in the 33 IGCP 582: IIT Kanpur, January 2012 area narrowing down natural flow spaces due to human encroachment i.e. construction of infrastructures, solid waste disposal etc. that provoke flow blockade during peak discharge and result in riverbank failure and inundation. It also triggers and enhances specific site erosion during low flow regime. Further, river incision in Kathmandu valley is rapid owing to sand extraction from riverbed and is denudating semi-consolidated Pleistocene mud of Kathmandu Basin deposit. Rapid channel entrenchment up to 7 m triggered intense bank failure. Lower terrace (former floodplain) with a height of 1.75 m from riverbed was developed in 3 years period. Although high flow discharge during monsoon is confined within the channel when the riverbed is deeply entrenched, possibility of bank failure is high owing to intense bank toe cutting. Extensive sand mining from riverbed has also enlarged the river valley width up to 75 m. Riverbank materials are consisting of sand, silt and gravels. Bank developed in paleo-channels deposit consisting of non-cohesive sediments (sand and gravel) are unstable. Bank collapse is found in high proportion in those areas of natural regime where degree of river sinuosity is high. When radius of curvature of the outer bend of river is very low, bank erosion is found more intense. In such areas maximum shifting of river course is about 400 m. Field properties identified in satellite images facilitate for hazard mapping. Figure 1: Location of the Study Rivers in Kathmandu valley BANK STABILITY ANALYSIS AROUND MAJULI ISLAND, ASSAM M. K. Dutta, R. Goswami and S Barman Department of Civil Engineering, Jorhat Engineering College, Jorhat, Assam Email: mrinaldk@rediffmail.com The susceptibility of the bank to erosion by various erosive processes and thus the stability of the bank and its characteristic mode of failure depend on the geometry of the bank, geotechnical and geological properties of the bank materials and the distribution of materials with different properties through the bank and velocity of river water at the bank. Again, the presence or absence of cohesion is particularly important. Majuli, the largest inhabited river island bounded by the river Subansiri to the north and mighty Brahmaputra River to the south, is one of the subdivisions of the Jorhat district, Assam. The geographical extent of the study area is 26°45' N- 27°12' N latitude and 93°39'E- 94°35'E longitude with mean height of 84.5 m above MSL. Erosion of the island is a continuous processes since historical times and posses a significant concern. The land area as evidenced till 1966-1975, 1998 and 2008 were 706.14 km2, 578.38 km2 and 484.34km2 respectively. The total average annual rate of erosion and deposition covering the entire period were 8.76 km2/ yr and 1.87 km2/ yr. It can clearly be attributed that the island mass suffered significant rate of erosion than the depositional processes. Again the process of erosion and deposition is not uniform throughout the island. In this study an attempt has been made to study the stability of bank considering geometry of the bank, geotechnical properties of bank materials and velocity of the river water at the bank. The bank stability analysis has differentiated the studied stretch 34 IGCP 582: IIT Kanpur, January 2012 into unstable, at risk and stable zones. Most of the erosion affected zones of the island under study are located within the unstable or at risk zones. The field study around Bengena Ati, Charigharia, Sarowati Gaon, Bechamara Mirigaon, Shikari Gaon and Serpaikhowa areas of the island with active erosion activity has supported our contention and practical utility of the present study. It is expected that such type of study will help in providing certain inevitable baseline information for various channel management practices for this extremely flood prone areas of Northeast India. RIVER CHANNEL ADJUSTMENT TO MEANDER CUTOFFS IN PART OF RIVER GODAVARI Maya Unde Department of Geography, Ahmednagar College, Ahmednagar, Maharashtra, India River menders are highly dynamic to being stable under some situation. They are major component of fluvial landscape. Mender cutoff is a specific type of avulsion where channel length and sinuosity are reduced through lateral erosion of the neck on the inside of a mender bend. Channel migration and mender cutoff are natural processes. The cutoffs of a meander usually produce a rapid in a river profile. The present paper will try to focus on how the cutoffs will make river to adjust into downstream and upstream of cutoffs. It will also study the fluvial processes and fluvial forms within the evolving cutoff. For the present paper part of river Godavari in Nashik and Ahmednagar district is selected for the study. Specific objectives of the proposed work are:1) Morphological evolution of cutoff channel, 2) Flow structures of channel at upstream and downstream , 3) Pattern of erosion and deposition. These objectives will be achieved by mapping, the exact morphology of the cutoff channel, the bed morphology and mapping patterns of erosional and depositional zone. For the present study part of river Godavari from Nashik to Jayakwadi Dam has been taken into consideration. The length of River Godavari is 215 kms. upto the back water of Jayakwadi Dam. Order of the stream is 8th. Numbers of Major tributary joins are -11th. Numbers of Major bends are 13th. Total 5 major cutoffs have observed in this region. While studying the area it is observed that most of the cutoffs have made main stream to adjust with the changing nature of cutoffs. The Godavari channel shows highly meandering nature in downstream of each major confluence. The River has started meandering just after its first major tributary Alandi, which join‟s the Godavari close to Nashik. On the basis of observation in the field and mapping of the area it can be said that channel avulsion are more likely to occur in channels with the slope, discharge, sediment load and width which place the near threshold. River reaches where meandering and cutoffs occur are typical locations where sediment supply exceeds the competence of the stream to carry sediment. 35 IGCP 582: IIT Kanpur, January 2012 TECTONIC FABRIC, PHYSIOGRAPHIC PATTERNS AND ISSUES OF STREAM DYNAMICS OF HIMALAYAN RIVERS Devashis Chatterjee There is a vast alluvial plain across the breadth of northern India (that extends into Pakistan and Bangladesh), built and watered by the rivers flowing down from the Himalayan ranges.. There are three trunk streams into which all the rivers flow: the Sindhu (Indus), the Ganga (Ganges) and the Brahmaputra. Together, they form the largest tract of fertile alluvium in the world, and symbolise – perhaps even define – the concept of India that is Bharat. The Sindhu (Indus) flows out from the Himalaya, traverses the plain and debouches into the Arabian Sea. The Ganga and Brahmaputra emerge from the Himalayan front, and flow through a plain bounded to the south by the highlands and plateaus of the Peninsula, until they pass through the Garo-Rajmahal gap to flow southwards to the Bay of Bengal. The domains of the three great rivers are defined by major tectonic structures transverse to the Himalayan trend More significant, these transverse structures reflect the extension of structures of the Peninsula. The wedge of the Peninsula is bounded between the Great Boundary Fault (GBF) of Rajasthan, and the fault along the eastern edge of the Rajmahal hills. The Indus system lies wholly in the shelf zone west of the Aravalli line. The Ganga basin is defined by the GBF and the Rajmahal promontory; the Brahmaputra flows westward till the Garo boundary. And the Teesta occupies the Garo-Rajmahal gap, concordant with the Teesta-Jaldhaka gap in the Siwalik belt. Apparently, the Teesta is a stream much smaller than the big three, but its significance is out of proportion to its scalar magnitude. The Indus basin is fairly simple, flowing direct to the Arabian Sea. The Ganga and the Brahmaputra are disposed in a symmetrical yet unequal pattern. These rivers and their tributaries cross the entire width of the Himalaya, emerge onto the plain (or foredeep), and flow east (Ganga) or west (Brahmaputra) till they meet. The Himalayan tributaries of the Ganga, as well as the main Alaknanda-Bhagirathi pair, dribble through the orographic grain with west verging (leftward on the map) bends; once in the plain, they drift south-east until the trunk channel forms. In contrast, the Brahmaputra group crosses in a series of east-verging bends, debouches to turn south-west, and the trunk stream flows west. In that tectonic gap crowned by the Kangchenjanga amphitheatre flows the Teesta, directly from the highest point to where it comes out of the ranges, and there it forms a giant splay like a delta, holding the Ganga and Brahmaputra apart. The different courses in the segments lead to different transport of sediment, and the interplay of the rivers at the head of the Ganga Brahmaputra delta is a complex and dynamic zone. The continuing uplift, consequent erosion, and the corridor for the full force of the monsoon winds add to the complexity. This is compounded by dams and structures to mitigate floods and erosion, all of which affect the silt load. 36 IGCP 582: IIT Kanpur, January 2012 In the context of climate change, and rise of sea level, the effects on drainage patterns, and the delta front become extremely sensitive issues. FLOOD INUNDATION MAPPING OF SAVITRI RIVER FLOODS- A CASE STUDY OF MAHAD CITY AND SURROUNDING REGION WITH THE HELP OF GIS Priyadarshani More*, Dr. V.R.Nagarale**, Dr. P.P. Magar*** S.N.D.T.Women’s University, Dept of Geography, PGSR, Pune-38 Email ID: priyadarshani.more@gmail.com, vr_nagarale@yahoo.co.in In many parts of the world, floods that invade river plains and coastal low lands are very serious natural hazards. Flood prone low areas are often densely populated and form the economic main stay of numerous countries. The food and health situation may be adversely affected by floods, and loss of life and property becomes even more severe where urban and industrialized areas are concerned. Accurate information on flood inundation, flood zonation is essential for designing a sound planning and management. It also provides the base line data required for proper understanding for how the floods has been occurred in the past/ and what magnitude of flood is excepted to occur in the future. This study will also yield valuable information for analysis of flood disaster. It is of great use to the recourse managers, planners, administrators as its provides the information that will be helpful in resolving the conflict between human and functioning of natural system. For the present study River Savitri has been selected which is one of the major west flowing river of coastal track of Maharashtra. It has a source at the Aurthorsit Point of Mahabaleshwar Plateau at an altitude of 1212 m. The basin lies in between 180 9‟ N to 730 40‟ E. The total catchment area of Savitri river is 2899 sq.km with total length of 99 km from its source at Mahabaleshwar to the confluence at Bankot. In the present paper flood inundation mapping for 2005 and 2007 flood events have been analyzed. For this all HFL markings of 2005 and 2007 events were recorded. Separate flood inundation maps were created for above mentioned flood events. The total area, total villages submerged and spatial extent of respective flood events computed. Problems related to flooding have greatly increased and there is a need for effective modeling to understand the problem and mitigate its disastrous effects. Human activities such as unplanned rapid settlement development, uncontrolled construction of buildings in general and major land use changes can influence the spatial and temporal pattern of hazards. There are several factors contributing to the flooding problem ranging from topography, geomorphology, drainage, engineering structures and climate. Most floods are caused by storms in the world in which a lot of precipitation falls in a short period of time, of both types of rainfall, convective and frontal storms. Intensity and duration of the rain are the most influencing factors for flood. In the recent years, remote sensing and GIS have been embedded in the evolution of the geo-environmental hazards. 37 IGCP 582: IIT Kanpur, January 2012 THE RESPONSE OF DRAINAGE BASINS TO THE LATE QUATERNARY TECTONICS IN THE SABARMATI RIVER BASIN, GUJARAT, WESTERN INDIA Girish Ch. Kothyari1, Siddartha Prizamawala2, Vamdev Pathak3, Prabhin Sukumaran1 and Mukesh Chauhan1, 1 Institute of Seismological Research, Raisan Gandhinagar, India 2 MS University Baroda, Vadidara, India 3 Indian Institute of Geomagnetism, Leelapur, Junsi, Allahabad, India E-mail: kothyarigirish_k@rediffmail.com Geomorphometric analyses permit the study of landform modifications that affect drainage basins, mainly changes due to active tectonics. The evaluation of geomorphic indices may be used to appraise the influence of active faults on the hydrographic network. A geomorphological analysis was carried out on Sabarmati drainage basins of the western Peninsular India. The Sabarmati River originates from Aravalli and flow almost SW direction and merge in Gulf of Khambhat. The upper catchment of Sabarmati River has been subjected to occurrence of earthquakes during the last centuries and considerable uplift during the Quaternary, as testified by the presence of uplifted fluvial terraces. The study has revealed the recent activity of some of the fault systems recognized in this area, and has allowed reconstruction of the evolution of the fluvial network which develops initially with an ESEtrending drainage direction. The Sabarmati river basin is controlled by NNE-SSW trending Cambay rift basin and criss-crossed by numerous E-W transverse normal faults. These faults are responsible for recent deformation and the consequent modification of the hydrographic network. The development of landform features and drainage network is combined effect of climate, lithology and the attitude of the strata, as well as active tectonics, regional uplift and subsidence (Guarnieri and Pirrotta 2007). The Sabarmati River basin contained five hydrographic networks drained by streams that flow into the Gulf of Khambhat (Fig.1). The channel of Sabarmati river is quite wide and dry during most of the year and characterized by extremely steep and high banks, flat and wide bottom and high gradient. The upper catchment shows along their entire course characteristics of bedrock channel, whereas towards the lower catchment it covers large alluvial cover with thickness of 200-400 m. To carry out the geomorphological analysis, we constructed a detailed field map of the landforms, as fluvial terraces, structural and geological elements. We have generated Digital Elevation Model (DEM) of Sabarmati river basin area in Global mapper-12. The DEM data was used to generate the drainage, lineament and shaded relief of the area to show the study of the landform features. The present day drainage pattern has been mapped using high resolution Satellite data (CORONA, ASTER and LISS-III). The geomorphological and structural mapping of the basing area has been done using CORONA photo stereopairs. The Geomorphic analysis of Sabarmati River has been done using the components (a) morphometric analysis and (b) morphostructural analysis. The Fluvial geomorphology of Sabarmati River basin is controlled by old geological structures belonging to Archean age and Cambay rift basin of Cretaceous (Fig.1) Along the fault traces we observed several geomorphological features, listed below: (1) fluvial capture due to headward erosion; (2) lateral migration of the drainage direction; (3) deflected streams; (4) offset fluvial terraces; (5) shutter ridges; (6) offset streams; (7) Box mindering 38 IGCP 582: IIT Kanpur, January 2012 Figure 1 Morphotectonic map of Sabarmati River basin. FLOOD HAZARD STUDIES IN NAGAPPATINAM DISTRICT, TAMILNADU, INDIA R.Baskaran Department of Earth Sciences, Tamil University, Thanjavur – 613 010 Nagappatinam district in Tamilnadu is a part of Cauvery river delta located along the east coast of India. Elevation from mean sea level, slope and geomorphology of the region increases the flood hazard at times of heavy rains due to tropical cyclones. The existing drainage structure and proper improvements made in them would help contain the flood hazard due to the cyclones which affects the agriculture in this area. Based on Geomorphology certain drainage structures may be envisaged in the form canals, ponds etc at locations where there is a possibility of storing the rain water and prevention of mixing of sea water due to tidal influxes. This paper discusses the drainage pattern and its effectiveness in containing the flood hazard in this district. STUDY OF BANKLINE CHANGES OF A STRETCH OF RIVER GANGA IN BIHAR USING MULTI TEMPORAL REMOTE SENSING DATA Shankar Dayal1, Atul Aditya Pandey 1, Ramesh Shukla1 and V.S. Dube1 Department of Geology, Patna University, Patna, India Email: Shankard656@gmail.com The 96 Km stretch in the middle Ganga valley, the river Ganga is flows in wide channel. The widening of the channel is due to descending tributaries in the plain. The tributaries discharge heavy sediment load and choked the river channel gradually and causes bankline failure. The mechanism involved and responsible for river bank erosion are related to inhomogeneity in bank material, geotechnical instability and sub- aerial weathering of sediments .The extent of erosion and deposition were not the same for many years. Temporal changes in the position of banklines of the river due to consistent bank erosion have been studied from pre monsoon (April) Landsat TM digital satellite data of 1975, 1988, 1999 and 2010 using RS and GIS. Two broad kinds of changes have been observed, e.g. there are defined section along the bankline which is very much prone to changes and also section along the bankline completely devoid of any changes. Study of bankline shift due to the bank 39 IGCP 582: IIT Kanpur, January 2012 erosion has been carried out for the periods 1975–1988, 1988–1999, and 1999–2010 at 8 sections spaced (average 12 km). The undercutting of the mid channel bars and alluvial islands are marked by the deposition of fresh sediments along the bankline. The dynamic nature of bankline helped in identification of strong erosional and depositional character along the selected stretch. The bankline have reshaped several time during the last 35 years. The study area stretches almost 96 km W- E from Chapra in the upstream upto Athmalgola in the down stream , covering lat 25044‟32”long 84041‟55”- lat 25027‟24” long 85032‟42” The river Ganga has four main tributaries in this stretch. River Ghagra and Gandak coming from Himalayan catchment (North) while river Son and Punpun coming from peninsular catchment (South).General flow direction of river Ganga is W-E .Near Chapra the river Ghagra coming from Himalayan catchment ( North) meets Ganga on the left bank. The flow direction of Ghagra in NW – SE .The peninsular river Son, which is coming from south meets Ganga on the right bank. The flow direction of river Son is NE – SW. Further downstream another Himalayan river Gandak, which is coming from north meets Ganga on the left bank .The general flow direction of river Gandak is N- S. Further down stream another river Punpun meets Ganga on the right bank. Therefore, the 0-21Km stretch on the right bank is dynamic bankline. Further downstream 22.2-38.3Km the river bank is dynamic .Again 42.6-48.4Km stretch the bankline is dynamic.71.6-80.8Km the bankline is dynamic and 82.3-96Km the bankline is dynamic. On the left bank at stretch from 0-13.6Km the bankline is dynamic.18.1-34.3Km the bankline is dynamic, 42.7-66.0 Km the bankline is dynamic and 70.6-96Km the bankline is dynamic. The dynamic character of the river shows that river has very strong erosional and depositional activity along these stretches during last 35 years and bankline has reshaped several times. VULNERABILITY ANALYSIS IN PARTS OF RAVI BASIN, CHAMBA DISTRICT, HIMACHAL PRADESH Pankaj Kumar, Arpita Pankaj, S. K. Ghildyal, R. K. Avasthy Geological Survey of India, Northern Region, Lucknow Email: pankaj.kumar@gsi.gov.in The study area lies on the northern slopes of the magnificent Dhauladhar range and falls under the Ravi catchment of Himachal Pradesh which is a part of the majestic Great Himalayan Range. The Ravi basin, with its historical and exotic scenic appeal, has ever remained an attraction for tourist and offers a vital passage to places of pilgrimage in Kinnar Kailash, Mani Mahesh and temple town Bharmaur. The road network in the area is frequently disrupted due to occurrence of landslides that badly affect the communication besides, causing delay in the timely completion of hydro-electric projects and other developmental work. The vulnerability analysis of the area is thus of immense help to the planners and administrators in context of developmental activities in the region. Geologically, the study area exposes rocks ranging in age from Lower Proterozoic to Recent and belonging to Dharamshala Formation, Salooni Formation, Panjal Volcanics, Katarigali Formation, Manjir Formation, Basantpur Formation, Mandi-Darla Formation, Kulu Group and Chamba Formation. These formations are folded into a major Chamba syncline along NW-SE direction. 40 IGCP 582: IIT Kanpur, January 2012 There is pronounced development of Quaternary deposits in the area, which are represented by valley-fill deposits such as fluvial terraces, debris cone and fans and glacial drift deposits. Based on the recorded landslide incidences, behaviour of slopes in each geological unit, slope class and slope category has been probed and used as an important parametric input in assigning hazard status to slope facets. Failure probability values for a given set of conditions, have been statistically calculated in percentage and the test case is then applied to slope facets showing similar geological and slope conditions presuming that similar slopes under similar conditions would behave similarly and would have same probability values. After extrapolation of data, in order to have a comparative assessment of landslide hazard proneness of different litho-units in the area, the relative vulnerability in terms of high, moderate and low hazard zones is tabulated in Table-1 and shown in Fig.-1. Thus this case study shows that the high hazard slopes are found to be most vulnerable for developmental activities whereas low hazard slopes in the above formations of the part of Ravi basin are found to be most suitable for urbanisation and other developmental activities. Fig. 1: Relative Vulnerability in different geological units Low Hazard Medium Hazard High Hazard Table-1: Vulnerability values in different hazard zones 41 Geological unit/ Group/ Formation Hazard zones Total no. of slopes No. of failed slopes Vulnerability value (%) DHARAMSHALA High 1 1 100.00 Moderate 5 2 40.00 Low 19 0 0.00 High 0 0 0.00 Moderate 4 2 50.00 Low 42 0 0.00 High 0 0 0.00 Moderate 3 1 33.33 Low 64 0 0.00 High 0 0 0.00 Moderate 14 4 28.57 Low 96 3 3.13 High 1 1 100.00 Moderate 12 5 41.67 Low 35 0 0.00 High 2 2 100.00 Moderate 15 6 40.00 Low 92 2 2.2 High 1 1 100.00 Moderate 0 0 0.00 Low 73 1 1.4 High 4 3 75.00 Moderate 10 3 30.00 Low 53 4 7.55 High 2 2 100.00 Moderate 26 10 26.00 Low 405 25 6.20 SALOONI PANJAL KATARIGALI MANJIR BASANTPUR MANDI-DARLA KULU CHAMBA IGCP 582: IIT Kanpur, January 2012 Session IV River response to climate change 43 IGCP 582: IIT Kanpur, January 2012 FLUVIAL SYSTEMS OF GUJARAT IN A CLIMATE CHANGE PERSPECTIVE: AN ANALYSIS OF PALAEOHYDROLOGY, PALAEODISCHARGE AND PALAEOCHANNEL DIMENSIONS Alpa Sridhar and L.S.Chamyal Department of Geology, Faculty of Science, The M.S.University of Baroda, Vadodara 390 002 The fluvial systems of Gujarat are sensitive to SW monsoon behavior and thus the climatic variability. The lasting effects of river flow on the landscape and on the sediment deposits can be used as indicators of change, both in time and space. These tropical sub-humid and semi arid river basins of Gujarat have preserved a relict drainage system and an array of geomorphic features that provide an opportunity to reconstruct palaeohydrological conditions that prevailed beyond the historical record. Regime and competence based palaeohydrological analysis has been employed to quantify changes in palaeoflood hydrology. The intriguing lithofacies diversity associated with the various Late Pleistocene to Early Holocene sediment archives in these basins, the under - fit channels, terraces and palaeo point bars have been used for palaeohydrological estimations. The results indicate that whereas the Late Pleistocene alluvial-fan and alluvial-plain facies sedimentation took place more in response to basin subsidence, providing accommodation space, rather than to changes in hydrological conditions, the sedimentation during Holocene was largely in response to changing hydrological conditions. Also the prevalence of „manifestly under- fit‟ channels with a lower meander wavelength than the valley meander indicate reduced precipitation, shrinkage of drainage network and associated changes in the hydrologic conditions and sediment supply through time. Fluvial aggradation under relatively low discharge conditions, punctuated by periods of higher discharge events occurred during the Early Holocene. The mid to late Holocene river systems probably had wider, large-amplitude meanders with greater width/depth ratio, unit stream power, the bed shear stress and a much higher discharge as compared to the present indicating a trend of decreasing precipitation since the mid–late Holocene. Palaeoflood records from the alluvial reaches of these basins suggest repetitive flooding in a regime of intense monsoon around 5 ka with a switch to extreme high magnitude floods in a period of low average precipitation towards the later part of Holocene (1.7 ka) and enhanced hydrological conditions around late medieval period. DECADAL VARIATION IN THE DISCHARGE OF CHHOTA SHIGRI STREAM WATERS LAHAUL-SPITI VALLEY, HIMACHAL PRADESH Alagappan Ramanathan, Parmanand Sharma Pottakkal George Jose & Anurag Linda School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110067 Email : alr0400@mail.jnu.ac.in Hydrological measurements have been carried out from 2003 to 2010 to understand the discharge processes variations during peak ablation seasons in the Chhota Shigri glacier. Discharge measurement carried out at hydrological station (discharge site, 3800m amsl) i.e. 2 km downward from snout (terminal of glacier, 4100m amsl) and water velocity was measured by float method and also cross checked with current meter. It was observed that the discharge peaked between 3.00 to 4:00 pm and reached a low at around 7:00 am in every sunny day, although it varies in rainy or cloudy days. Generally May–June discharge is extremely poor than 44 IGCP 582: IIT Kanpur, January 2012 July-August discharge that is only 10-15% of July–August discharge. The coefficient of variation of runoff as a function of the percentage of glacier cover in a catchment indicates the impact of glaciers on the runoff. Also in glacial (reservoir beneath the glacier) storage can reduce peak runoff during periods of intensive melt and rain. Alternatively, the stored water can be catastrophically released from hidden reservoirs in the interior of the glaciers and changed entire picture of discharge. Mean discharge of Chhota Shigri glacier stream during July- August between 3.004.00pm were 4.92 m3/s, 4.11 m3/s, 4.06m3/s, 4.26m3/s, 4.19m3/s, 4.31m3/s, 4.94 m3/s and 7.92 in year 2003, 2004, 2005, 2006, 2007, 2008, 2009 and 2010 respectively while overall mean discharge were 3.1 m3/s, 3.23 m3/s, 3.42 m3/s, 3.33 m3/s, 3.65 m3/s,3.36, 4.14 m3/s and 6.92 in 2003, 2004, 2005, 2006, 2007, 2008 and 2009 respectively. Discharge of present decade seems to be very low compared tp previous decade study i.e. 10 m3/s (1988) during July-August. It reflects that this glacier is a major contributor of fresh water in local scale but slowly it is decreasing due to reduced discharge (almost 0.3 to 0.4% per annum since 1988 to 2003).After 2003 there is almost similar upto 2008 ,while it is shows decreasing trend from 2009 onwards. Negative mass balance over the study period with net annual balances of -1.4 m w. eq. 1.2 m w.eq., +0.1 m w.eq., -1.4 m w.eq., -1.3 m w.eq., -0.93 m w.eq., 0.11 m w. eq. and 0.33m w.eq. in 2002-2003, 2003-2004, 2004-2005, 2005-2006, 2006-2007, 2007-2008, 2008-2009 and 2009-2010 respectively was observed . The rate of change in ice volume is -0.01 km3 year-1 and there a 28% loss in ice volume from 1989 to 2010. This variation in discharge is correlated with mass balance results. Positive mass balance year revealed more discharge due to more snow cover area. The discharge was similar during all negative mass balance year while high discharge was observed during positive mass balance year. Aablation pattern on glacier surface is a dominating factor that controls discharge in the stream. Although during positive mass balance that increase albedo can reduce melting of snow and ice but due to excess catchment area cover by snow and melting contribute more meltwater to stream that increases the discharge. AGGRADATION DURING THE EARLY HOLOCENE STRENGTHENED NE MONSOON AND RAPID RECENT INCISION OF THE COASTAL TROPICAL RIVERS, CHENNAI, TAMIL NADU Achyuthan H and Nagasundram M. Department of Geology, Anna University Chennai 600 025 hachyuthan@yahoo.com Coastal Chennai region is drained by parallel meandering rivers such as the: the Koratallaiyar, Coovum, Adyar and Palar. These rivers mimic each other in their meandering and flowing pattern; draining over and cutting the Precambrian charnockite and Upper Gondwana sandstone and shale and then entering the Bay of Bengal with no delta formation towards the East. The Late Pleistocene-Holocene fluvial sediments overlie an erosion surface that at several sites has cut into older Pleistocene sediments and Late Neogene ferricrete surface. Incised valleys that cut into this erosion surface are nearly 5–6 km wide and have a relief of at least 30 m and the largest valley is cut by the Koratallaiyar and the Palar Rivers. Holocene sediments deposited in the incised valleys include fluvial gravels, channel sands and floodplain silts. Presently, all the rivers lack significant stored sediment, suggesting that fluvial erosion and 45 IGCP 582: IIT Kanpur, January 2012 transport capacity outpace the supply of sediment from the upland areas. The flow pattern of these coastal rivers is governed by N-S fault; NW-SE and NE-SW lineament propagation. The Koratallaiyar and the Palar formed two terraces while the Cooum and the Adyar only one. The highest terrace is located on the Koratallaiyar and the Palar nearly 6-5 m above the present river bed that constitutes the top of the fill. The other terraces are cut and fill terrace of the Cooum and Adyar nearly 3 m above the present day river bed. Bore hole data of the river sediments indicate an aggradation phase of nearly 20-22m-thick of coarse colluvium overlain by nearly 180 cm of fine silty sand over bank deposits. River cut sections reveal coarse, ill sorted colluvium sequence indicating deposition by high intensity channel processes. Pedogenic mottled, clayey silt units within coarser silt layers with clay nodules above the colluvial deposit represent an important tectonic event when the channel was temporarily drained and sediments were sub aerially exposed. Uplift of the region in the recent years has caused these rivers to incise into the landscape forming degradation terraces. 14C and OSL dates of the sediments from the three rivers range in age from 6 ka to 175yrs BP and indicate an Early Holocene-Mid Holocene valley fill. Differences in terrace height (5–3 m) observed above the modern river bed in the Koratallaiyar, Cooum, Adyar and the Palar Rivers; the fluvial surfaces display dissimilar ages. Radiometric dates on colluvium and fine grained overbank sediments indicate that sediment at least 20-22 m thick filled the Koratallaiyar and the Palar River basin during strengthened NE monsoon since the Early Holocene period. We speculate that enhanced NE monsoonal precipitation during the Late Pleistocene-Early Holocene period increased pore pressure and the frequency of earth quakes thereby generating a pulse of upland-derived coarse sediment that overwhelmed the fluvial system's transport capacity. Aggradation in the Koratallaiyar-Palar basin has resulted from dynamic adjustment of the hydrological system to the wetter conditions in the early Holocene, when water discharge might have been about three or four times higher than the present. By 5.5 ka the colluvium was exhausted, the flux dropped, and the river incised through the aggraded colluvium. Subsequently a rather dry climate with enhanced seasonality prevailed from the mid‐Holocene (~6 ka B.P.) followed by rapid incision of fluvial overbank sediments until now. A gradual decline in river slope during the incision/ down cutting throughout the riverbed took place during the late Holocene-Recent times. River slope is one of the major factors for specific discharge and volumetric discharge of these near coastal rivers. It also eroded bedrock and the coastal river basin preserved signatures of a coupled fluvial response to climate, sea level change and neotectonics. Several causes are responsible for variable sediment flux in this tectonic setting including Holocene climate change and ground accelerations related to earthquakes. 46 IGCP 582: IIT Kanpur, January 2012 PALAEOCLIMATIC AND TECTONIC INFLUENCES ON ALLUVIAL SEDIMENTATION OF TAPI BASIN, CENTRAL INDIA Snigdha Ghatak 1, Mriganka Ghatak 2, Anjan Kumar Chatterjee 3 1 Geological Survey of India, DGCO, New Delhi 2 SAARC Disaster Management Centre, New Delhi 3 Geological Survey of India, Nagpur Corresponding author email: snigdha_b@yahoo.com The Tapi basin, embraced by the ENE-WSW trending Tapi Fault Zone (TFZ), has witnessed several episodes of Late Cenozoic crustal adjustments and climatic regimes. The Quaternary alluvium (~400m thickness) of braided to meandering Tapi River occur dominantly in form of overbank/ channel deposits and is accumulated at the southern downthrown block at the foothills of Satpuras. With an aim to understand the stratigraphical and palaeoclimatic evolution of this basin, detailed field investigations and analysis of the litho packages for the continental climate proxies like palaeosols and various types of calcretes from two different composite key sections in parts of Tapi basin; Takarkheda in the western part and Palasur in the eastern part, were taken up with chronological control provided by OSL dating. Takarkheda section exposes 18m thick alluvial sequence of three different litho units: basal red palaeosol and multiple bedded calcrete association; pebble-sand-calcrete association and fine grain sand in ascending order. The lower red clayey palaeosol/pedosedimentary unit is characterized by six bedded calcretes of stage III to IV maturity, high smectite content and presence of abundant feldspar indicating an overall high rainfall scenario, short distance of transport, flood plain aggradation events interspersed by periods of reduced sediment flux and stability. Transformation and predominance of beta to alpha calcrete up in the calcrete profile suggests climatic amelioration during the waning phase of red palaeosol formation and probable shallowing of ground water table in a slowly sinking basin due to gravity faulting along TFZ. OSL estimates from the upper part of this red palaeosol unit yields an age of 139Ka corresponding to a monsoonal high in the Indian context. The overlying unit 2 indicates a rejuvenated fluvial regime, probably corresponding to a major tectonic event along TFZ under a climate conducive for bedded calcrete formation. Unit 3 deposited in inset terraces represents high stream energy during ~5000 Ka. At the eastern part, in Palasur, the river is flowing through an ENE-WSW trending fault controlled intermontane valley and exposes three sedimentary units: basal gravel-palaeosol- ash bed association; pebbly sand-buff palaeosol and silty clay in ascending order. The basal red silt unit represents flood plain aggradation during ~57.5Ka. Red colour of the soil, abundance of smectite and presence of beta fabric (rhizoliths) indicates a high rain fall phase and biogenic control on pedogenesis. The presence of evaporation related shrinkage cracks in calcretes (stage II maturity) at the top of red palaeosol indicates climatic amelioration. Abundance of smectite in unit 2 points towards a high rainfall spell between 27,000 Ka and 17,000 Ka. Presence of beta fabric from this soil indicates pedogenetic origin while carbonate cemented grit bed at the top of unit 2 indicates an overall arid phase synchronous with LGM. Unit3; low on carbonates and rich in smectite, dates back to 8000 Ka with evidences of bed load traction in high rainfall phase. On the basis of field evidences of faulting, alluvial architecture and chronological data it is evident that sediment package at Takarkheda and Palasur represent sediment flux from two different fault segments of TFZ 47 IGCP 582: IIT Kanpur, January 2012 and preserves signatures of Indian climatic variation. Considering the fact that fault segment controlled sedimentation/hiatus in sedimentation varies spatially and temporally aided by climatic variation, a four tier classification of the sediments could be arrived at within a time frame of middle Pleistocene to Holocene. From the present study, five episodes of tectonic upliftment in TFZ interspersed with four periods of tectonic stability, soil formation and activation of local fluvial systems could be identified. INFLUENCE OF TECTONICS AND CLIMATE ON HOLOCENE BAJADA SEDIMENTATION ALONG NARMADA-SON FAULT (NSF), GUJARAT, WESTERN INDIA Parul N. Joshi*, D. M. Maurya and L. S. Chamyal Department of Geology, The M. S. University of Baroda, Vadodara-390002, Gujarat, India An alluvial bajada have been recognized along the Narmada-Son Fault (NSF) in mainland Gujarat, which is confined by Karjan River on the eastern side and by Madhumati River on western side. This has been studied in their proximal, medial and distal part. The sediments are characterized on the basis of grain size, fabric, sedimentary structures, bed geometry and sorting and lithologs prepared for the mapped cliff sections. Lithofacies characteristics and facies associations indicate that sediments are of mainly three typessediments that were deposited by debris flow and sediment gravity flow, and as extensive bar deposits. Vertical change in the sedimentary facies indicates three sequences of sedimentation. Each sequence is composed of coarsening-upward sequence of proximal facies overlain by fining-upward sequence of distal facies. Coarsening upward period record the periods of tectonic uplift related the NSF and fan progradation, whereas fining-upward sequence results from tectonic quiescence periods. The presence of rhizocretions, calcium carbonate nodules and calcite sheets within the basal debris flow and sediment gravity flow deposits indicate semi-arid climate, whereas the formation of pedoginized paleosol and large, extensive bar deposits indicate sub-humid climate prevailing in the study area. Tectonic activity along the NSF has played dominant role by controlling the geometry and volume of bajada sediments. Climate is found to be responsible for compositional and temporal distribution of the bajada sediments. SEDIMENT STORAGE AND EVACUATION EPISODES DURING THE LATE QUATERNARY IN THE WESTERN DEHRADUN REGION: A GIS APPROACH Swati Sinha1, Rajiv Sinha1, Alexander L. Densmore2 1 Department of Civil Engineering, IIT Kanpur, India 2 Department of Geography, University of Durham, UK The geomorphic analysis based on conventional techniques such as topographic maps has improved significantly with the advent of new digital techniques implemented using Geographical Information System (GIS). GIS allows quantitative measurements of landforms and the identification of geomorphological features at a variety of scales. The study area for this paper includes the Western part of Dehradun valley of NW Himalayas. The intermontane valleys, locally known as „Duns‟, have mainly occupied the topographic „recesses‟ associated 48 IGCP 582: IIT Kanpur, January 2012 with frontal Himalaya. Several geomorphic units have been identified in this area including alluvial fans, active and inactive flood plains, talus slope and terraces. The relative timing of the deposition of the different fan surfaces has been established using the published OSL dates. Correlation of fan depositional surfaces across the study area has allowed us to estimate the volumes of Quaternary fill in the Dun and the amount of material excavated during episodes of fan incision. The widespread trapping of sediment in the Dun is mainly caused by growth and lateral propagation of the Himalayan frontal fault system and the Mohand anticline. Variations in storage or excavation on short time scales (50-100 ka to present) are mostly controlled by sediment supply from the catchments and climate modulated changes. The isolated hills of the fan (IHF) have been interpreted as the oldest fan surface. The Upper fan (UF) surface is the second phase of the fan development with the OSL dates in between 30 ka to 20 ka. The Lower fan surface (LF) is the youngest fan surface with OSL dates in between 17ka to 11 ka. The current analysis uses GIS techniques for a better visualization into the past. The surfaces were extracted using ASTER DEM with 30 m horizontal and 10 to 25 m vertical resolution. The total accumulation of the sediments within the fan surfaces since ~50 ka is 1.95x1011 m3 and the average sediment flux for the stored volume within the 50 ka year time period is 1.7x10 8 m3 /yr. The volume of the eroded material from the surfaces within the time span of 50 ka is estimated at 1.1x1010 m3. We believe that the Duns have undergone several cycles of sediment filling and excavation and that the duns have acted as „filters‟ for modulating the sediment supply into the plains. Further investigations are ongoing to relate the episodes of sediment filling and excavation to climatic/tectonic events. COMPLEX SCENARIO OF FLUVIAL GEOMORPHOLOGIC RESPONSES TO GLACIAL MELTING: A FIRST ORDER SYNTHESIS FOR THE HIMALAYAN RIVERS L. Sardine Varay and Vikrant Jain Department of Geology, Centre of Advanced Studies, University of Delhi, Delhi Emails: sardinevaray@rediffmail.com, vjain@geology.du.ac.in Fluvial processes are governed by variation in discharge, channel slope and sediment supply. Enhanced glacial melting in response to climate change will have a direct bearing on the two key parameters of water discharge (Qw) and sediment load (Qs). River discharge in the Himalayan-sourced Rivers is governed by rainfall, snow and glacier melt. However the proportion of contribution varies spatially and temporally. Remotely sensed data showed that a snowmelt contribution to annual discharge is 50% in the far western (Indus area) catchments, ~25% in far Eastern (Tsangpo) catchments and < 20% elsewhere1. Also the snowmelt contribution is significant during pre and early monsoon season (April to June) and is most pronounced in the western catchments1. The contribution of snow and glacier runoff to the annual flow is 60% at Bhakra Dam in the Sutlej basin2, 49% in Chenab river at Akhnoor3 and 35% in Beas river at Pandoh4, while in the Ganga basin, snow and glacier melt contributes 29% to the annual flow of Ganga at Devprayag which further reduces to <4% at Allahabad 5. On the other hand, limited data on sediment supply due to glacial erosion also highlights significant effect on sediment supply. For example, 60% of sediment load in Karakoram6 and 64 % sediment in Din Gad basin originating from Dokriani glacier are glacier-derived7. Long term monitoring of sediment load in the Himalayan basins is lacking. However, enhanced glacial 49 IGCP 582: IIT Kanpur, January 2012 melting and glacial retreat will unravel new sediment sources and will initiate sedimentgenerating processes like Glacial Lake Outburst Floods (GLOFs), permafrost degradation, slope failure and increased discharge from meltwater, which will increase sediment yield of river basins. The variability in glacial derived fluxes indicates that even a similar glacial response to climate change will have variable effects on different fluvial systems. Further, different models have predicted variability in glacial sensitivity in response to climate change. SNOWMOD model predicts higher acceleration of snowmelt in early and late parts of ablation season in the event of future temperature increase in the Sutlej basin 8 whereas downscaled General Circulation Models (GCMs) show that hydrologic responses of rivers to climate changes will vary with latitude and the largest changes are predicted for the snowdominated basins of mid to higher latitudes9. On the other hand, snow accumulation are poised to increase in certain high latitude areas10. Differential glacial sensitivity to climate change is also recorded in the Quaternary records, which suggest that glacial advances during Quaternary were not synchronous throughout the Himalaya11. Integration of data thus throws up heterogeneity and complexity of hydrologic responses in relation to glacial-fluvial interaction. There is currently a lack of comprehensive understanding on a) glacial responses to climate change and variability in glaciogenic fluxes and b) river response to glaciogenic flux variability. An in-depth understanding of glacial-fluvial relationship in different basins will help to better constrain the evolutionary path of a fluvial system. THECAMOEBIANS AND PALYNOLOGICAL ASSEMBLAGE IN THE TRIBUTARY OF UPPANAR RIVER, CAUVERY DELTA, INDIA: ENVIRONMENT AND SEA LEVEL SINCE 4000 YEARS Jyoti Srivastava*, Anjum Farooqui and S.M Hussain1 Birbal Sahni Institute of Palaeobotany, 53 University Road, Lucknow -226007, UP 1 University of Madras, A.C. College Campus, Chennai-600025, Tamil Nadu *Corresponding author:caprice2628@yahoo.com Palaeoclimate and Palaeoecological study was carried out using palynological and thecamoebian evidences buried in ~2 m sediment core of Late Holocene age obtained from the estuarine area in a tributary of Uppanar River, Cauvery Delta. Inferred climatic periods include (1) a basal warm period (~4000-3000 yrs BP) characterized by sandy sediment, high percentage of foraminiferal linings and Poaceae with a low percentage of mangroves indicating a river mouth bar and (2) a dry and arid period (since ~3000 yrs BP) characterized by clayey sediment with an increase in dinoflagellate cysts and a low percentage of foraminiferal linings which indicates the presence of an estuarine ecosystem. A shift in the estuarine area seawards since ~3000 yrs BP indicates a gradual fall in relative sea level. During this period dominance of Avicennia and Cheno/Ams indicate low freshwater runoff from land suggesting a weakened monsoon enhanced by coastal anthropogenic activity. 50 IGCP 582: IIT Kanpur, January 2012 Session V River Landscape evolution, subsurface stratigraphy and sediment geochemistry 51 IGCP 582: IIT Kanpur, January 2012 GEOMORPHOLOGICAL STUDY OF THE LAND FORMS PRODUCED BY THE TROPICAL RIVERS AND LAND USE IN BAGMARA UPAZILLA, RAJSHAHI DISTRICT, NORTHWESTERN BANGLADESH 1 Dr. Mrinal Kanti Roy, 2 Md. Aynul Haque and 3Raman Kumar Biswas ,2 Department of Geology & Mining, University of Rajshahi, Bangladesh Email: mkr_c@yahoo.com, anuhaque85@gmail.com 3 Department of Environmental Science and Disaster Management Patuakhali Science and Technology University, Dumki-8602, Bangladesh E-mail: rkb07_jh@yahoo.com Physiographically, the study area of Bagmara Upazilla, Rajshahi, Bangladesh covers 363.30 sq. km of Recent to Holocene Northern Ganges floodplain in southern part and natural levee-flood basin in the northern part. The identified morphological units are active channel deposits, abandoned channel deposits, natural levee deposits, flood plain deposits, flood basin deposits, back swamp deposits and old bar deposits. The sub-surface litho-succession is composed of channel, bar and over bank fine deposits, which usually form fining upward sequence. Three numbers of sedimentary cycles compose the litho-succession up to 60m depth of the study area. The lower most channels of the litho-succession are of high velocity rivers in alluvial fan set-up having gravelliferous fills. The channels in the middle part of the lithosuccession are of braided nature composing of coarser channel deposits in greater proportion than over bank fines. The channels of the upper part of the litho-succession are also large meandering rivers characterized by the equal amount of channel and over bank fine deposits. The panel diagram and stratigraphic cross-sections suggest that in Plio-Pleistocene time the rivers flowed towards south to meet the Padma like trunk river, which is still present to the south of the investigated area. But due to neo-tectonic activities in the Holocene-Recent time the southern part of the study area, which is also northern bank of the river Padma might had been uplifted. Under this situation the present rivers like Barnai, Rani and Sib of the study area have shifted their course towards east to meet with Jamuna like braided rivers located east of study area and become meandering now with two level of floodplains, large back swamps and flood basins, suggesting late matured to old stage of the rivers. On the basis of geomorphological parameter, surface and subsurface lithology, drainage system and land use pattern seven number of land elements have been delineated in the study area. Land element-1 is active channel. This element can be successfully used for pisciculture and navigation. Long strip of channel can also be used for tourism. Land element-2 is channel bar deposits, used for agriculture and engineering purpose. The element can also used for construction, earth fill and some bar use for housing and settlement. Land element-3 is abandoned channel deposits. This element can be successfully for pisciculture and elevated part for paddy cultivation. Land elment-4 is natural levee deposits. This element can be used for human settlement, for the construction of roads and highways. Land element-5 is flood plain. This element is suitable for agriculture. The older (upper) flood plain can be used for settlement and for the construction of road. Land element-6 is flood basin and 7 is back swamp deposits, which can be used for pisciculture. This combined element can also be used for water reservoir and solid waste deposal site. Local existing township, hat, bazar and communication network (metal and un-metal) are located mostly in natural levees and old bar 52 IGCP 582: IIT Kanpur, January 2012 deposits. Villages occupy mostly the elevated part of the floodplains, old bars and to some extend natural levee. For future urban development land element-2 (natural levee) and 3 (floodplain) are most suitable. Land element-4 (Back swamp/Flood basin) is regarded less important for any type of settlement for urban development because of annual flooding, water logging and clay rich sub-soil condition. Tectonic activities are being playing important role in changing the river course. EVIDENCES FOR BURIED CHANNELS OF A LARGE RIVER IN THE GHAGGAR PLAINS, NORTHWEST INDIA Ajit Singh1, Rajiv Sinha1, Sanjeev Gupta2, Andrew Carter3, Debajyoti Paul1 and Philippa Mason2 1 Indian Institute of Technology Kanpur, India, 2Imperial College London,UK, 3 Birkbeck and University College of London, UK This study presents subsurface evidences for the presence of a buried channel of a large river beneath the Ghaggar plains based on remote sensing, subsurface drill core lithostratigraphy, and sediment provenance studies using U-Pb detrital zircon ages. The semi-arid Ghaggar plains of NW India presently comprises of the ephemeral Ghaggar river that originates in the sub-Himalaya and occupies a large paleo-valley. Several workers have identified surface signatures on satellite imageries and have concluded the presence of a network of large and small buried channels beneath the Ghaggar plains. However, very little subsurface investigation has been carried out to strengthen these findings. In this study, we first identified the trace of the major buried channel on the Landsat 5 false colour composite (FCC) prepared using the thermal bands. The FCC shows the trace of buried channel running through the Ghaggar plains in downstream stretches, and through the Sutlej plains in the upstream stretches. Second, we retrieved sediment cores through drilling down to depth of ~50 m, across four transects along the length of the identified buried channel. Drill core litho-stratigraphy shows ~20-25 m thick micaceous coarse- to medium-sand bodies at variable depths below ~5-8 m. These sand bodies are identified as fluvial sequences deposited by a large river. Further, to establish the provenance signatures of the core sediments, we determined UPb ages of detrital zircons from different depths of the drill cores. Finally, U-Pb age of detrital zircons were also determined for the modern river sands of the Sutlej, Ghaggar, Yamuna, and Ganga rivers to generate the fingerprinting signal and to identify the possible flow paths for the buried channel. The probability distribution function of U-Pb ages of core sediments show prominent age peaks corresponding to Higher and Lesser Himalayan provenance, suggesting mainland Himalaya as a major source for the buried channel. A comparison of probability distribution function of core sediments U-Pb ages with that of modern river sands shows closest match with the Sutlej river. We therefore conclude that the thick subsurface sand bodies are the palaeochannel deposits of a large river system, most likely the Sutlej, sourced in the mainland Himalaya rather than the frontal ranges. The buried channel represents the former course of the Sutlej which avulsed/diverted to present course at some point of time in the past. The depositional ages of core sediment are being determined through luminescence dating to constrain the timing of the change in the course of Sutlej. 53 IGCP 582: IIT Kanpur, January 2012 CONTROLS ON LATE QUATERNARY SEDIMENTATION IN THE INTERMONTANE VALLEYS OF NW HIMALAYA Vimal Singh Department of Geology, Centre for Advanced Studies, University of Delhi, Delhi - 110007 The presence of intermontane valleys in the tectonically active (compressional regime) areas is result of spacing between the thrusts, which in turn is controlled by various factors such as basal slope, thickness and lithological character of the stratigraphic sequence and basal friction. Due to differences in these parameters the intermontane valleys may differ in their morphological characteristics. For example, Pinjaur dun and Dehradun show several differences in their dimensional characteristics such as length (Pinjaur dun ~ 150 km; Dehra dun ~ 80 km), width (Pinjaur dun ~ 8-20 km; Dehradun ~ 15-20 km) and valley floor elevation (Pinjaur dun ~ 290 - 700 m; Dehradun ~ 310 - 1000 m). Apart from dimensional variations the elevation of the mountains bounding intermontane valley may also vary. Elevation of these mountains influences the sedimentation processes in the intermontane valley because the streams draining these valleys mostly originate in these adjacent mountains. On the other hand, the sedimentation processes is also governed by tectonic processes within the intermontane valley and the climatic processes. Therefore, intermontane valleys provide an excellent site to investigate the control of morphology, tectonics and climate on the sedimentation processes. This study compares two intermontane valleys located in the NW Himalaya, viz., Pinjaur dun and Dehradun. Pinjaur dun can be divided in to a wider north-western part (also called as Soan dun by some workers) and a narrower south-eastern part, whereas Dehradun is fairly continuous but it can be subdivided in to western (also called as Kiarda dun) and eastern part with Yamuna River forming the boundary between the two parts. Differences in sedimentation are observed even in the two parts of the duns. For example, south-eastern part of the Pinjaur dun shows continuous sedimentation from  55 ka to  9.8 ka with cessation of sedimentation in the distal part of the fan around  27 ka due to activity along the Pinjaur Garden Fault; whereas the north-western part shows cessation of sedimentation in the proximal part at  20 ka and around ~ 24 ka in the distal part in response to incision by the Sutlej River (Singh et al., under preparation). Previous study (Singh et al., 2001) in Dehradun (eastern part) show continuous deposition from ~ 50 ka to 10 ka and it also suggests strong control of the active structures on the sedimentation processes since the formation of depositional units. On the other hand, in the western part the sedimentation is suggested to have occurred between  34 to  19 ka (Philip et al., 2009). Therefore, it can be noticed that even in the case of Dehradun the sedimentation processes do not show much similarity. Comparing the two duns, it is observed that both the duns show preservation of sedimentation history of last ~ 50 ka (however, north-western part of the Pinjaur dun shows even older ~ 84 ka sediments as well) and incision at around 10 ka. However, there are variations in sedimentation processes in these two valleys within the span of 40 ka. These variations are explained by tectonic activities, climatic variability, drainage spacing, and nature of axial river. 54 IGCP 582: IIT Kanpur, January 2012 Sr ISOTOPIC SIGNATURES OF SURFACE WATER, GROUNDWATER AND SEDIMENTS OF GOMATI RIVER AROUND LUCKNOW IN GANGA ALLUVIAL PLAIN, INDIA Sandeep Singh1, Munendra Singh2, Vipin Paliwal1, K G Geetumol1, Anurag Srivastava1, Nupur Srivastava2 and A.K. Choudhary3 1 Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee – 247667, India 2 Department of Geology, University of Lucknow, Lucknow-226007, India 3 Institute Instrumentation Center, Indian Institute of Technology Roorkee, Roorkee – 247667, India Interactions between groundwater and surface water are complex and depend on many factors including landforms, geology, climate and the exploitation of local water resources. Hydrology and water quality of rivers are, therefore, strongly controlled by exchange of water and solutes with lithology of the drainage basin. During recharge processes, groundwater acquires Sr isotopic signature and moves into river water through interaction with Sr-bearing minerals present within lithological units. To understand these complex processes in the Ganga Alluvial Plain, data have been generated from surface water, groundwater and alluvial sediments along the Gomati River around Lucknow located in central part of the Ganga Alluvial Plain, northern India. The Gomati is a groundwater fed river with its entire drainage lies within the Ganga Alluvial Plain. It originates from the Madho Tanda located about 50 km south of foothills of the Himalaya. It extends about 900 km and meets the Ganga River near Saidpur. The river drains about ~ 30,000 km2 area of the interflue region of the Ganga and the Ghaghra Rivers. The Gomati River basin experiences humid sub-tropical climate with the hot summer season followed by heavy precipitation during the monsoon season and the winter season. Variation in temperature is as high as 47 C in the summer season while it becomes about 2 C during the winter season. Major part of rainfall is concentrated in the monsoon season during July to October with only few sporadic rains during the winter season. Average annual rainfall in the Gomati basin is about 1025 mm. About 75% of rainfall in the Gomati Basin is either returned to atmosphere through evaporation/evapo-transpiration and/or stored as groundwater. Hydrology of the Gomati River is characterized by very low discharges during the winter and summer seasons. In the monsoon season, the river‟s discharge increases manifold due to heavy monsoon rainfall and diminishes during the post-monsoon season. The Gomati River enters in Lucknow area about 360 km downstream of its origin and meanders for about 12 km. For the present study of interactions between surface water, groundwater and alluvial sediments, samples have been collected and Sr isotopic data have been generated. For surface water, samples have been collected at Lucknow in January, 2006. For groundwater, 109 samples were collected from hand pumps (shallow level of 30-32 m deep) and i.e. tube wells (deeper level 60-65 m) within Lucknow area in grid fashion between June and July, 2010. For sediments, samples have been collected from a vertical cliff exposed near Behta Nala in Malihabad, Lucknow. All water samples have been collected in cleaned polypropylene bottles filled with deionised water. The deionised water was decanted and the bottles were washed with water two to three times before the water samples were collected. Sediment samples 55 IGCP 582: IIT Kanpur, January 2012 were collected from different lithological entities of the 9 m high cliff section. All the samples were brought to Indian Institute of Technology, Roorkee laboratory for Sr isotopic analysis. The water samples were filtered in the laboratory by using 0.45 micron nitrate membrane filter in the laminar flow and the sediments were further pulverised in the agate mortar. The 87Sr/86Sr isotopic ratio of the surface water at Lucknow is about 0.73075. However, the 87Sr/86Sr isotopic ratio of the shallow groundwater ranges between 0.72125 and 0.72916. The 87 Sr/86Sr isotopic ratio of the deeper groundwater ranges between 0.72436 and 0.72552. At the same time, the isotopic ratios of alluvial sediments collected from the vertical cliff range from 0.72439 to 0.76547. The spatial variation of isotopic data clearly indicates that the groundwater samples nearer to the Gomati River have higher Sr isotopic ratios than samples which are away from the main river. The gradual decrease in the isotopic ratio from the surface water to the shallower groundwater to the deeper groundwater is recorded. However, a detailed model is required for the monsoon rainfall-alluvial sediment interaction vis. a vis. to climatic change for the Gomati River and the Ganga Alluvial Plain in northern India. SOURCE-TO-SINK STUDIES OF DRYLAND TROPICAL FLUVIAL SYSTEM: A CASE STUDY FROM RUKMAVATI RIVER, KACHCHH, WESTERN INDIA Nilesh Bhatt*1, S. P. Prizomwala1 and N. Basavaiah2 1 Department of Geology, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara; *email: nilesh_geol@yahoo.com 2 The Indian Institute of Geomagnetism, New Panvel, Navi Mumbai, INDIA The source to sink studies envisages the fate of sediment as it is derived from the uplands (i.e. the source), its transport coupled with partial storage along the pathway and ultimately its deposition into the ocean (i.e. the ultimate sink). The research with this regard has been focused upon mostly large rivers systems and their sediment delivery into the ocean, whereas there exists little published work on sediment delivery from small fluvial systems, although they are characteristic of arid and semi-arid climate regimes which cover a significant land mass in the tropical areas. Dryland rivers are typically known for transporting large amount of sediments from their highly erodible channel beds to the sea, due to their characteristic precipitation nature. Mostly these rivers are characterised by high intensity of rainfall during limited period leading to bankfull discharge for a short period (i.e. flash floods). Owing to arid climatic regime the channel beds are mostly dry and lack vegetation and hence offer no resistance to sandy bed erosion, leading to transportation of large amount of sediments. In a source to sink study one of the primary requisite is to have understanding of the discriminating characteristics of different end members contributing in the basin area, more likely using different proxies, which would enable in better tracking of particular sediments during their transit. Here we present our study on one of the major rivers of Kachchh mainland – the Rukmawati River which debouches its sediment load into the Gulf of Kachchh, one of the largest macrotidal regimes in Asia. The study demonstrates the application of environmental magnetism, heavy mineral analysis and clay mineralogy in provenance discrimination from a catchment taking into account both, bed load and suspension load modes of sediment transport. We have documented all possible sources of sediments being derived from one end member (i.e. Kachchh 56 IGCP 582: IIT Kanpur, January 2012 mainland) to the Partial sink (i.e. Gulf of Kachchh in this case) and being ultimately delivered off the continental shelf off the mouth of Gulf of Kachchh into the Arabian Sea. The „uplands‟ and „Deccan trap‟ are two characteristically different sources of sediments to the Rukmawati river basin. The „lower reaches‟ exhibits the mineralogical assemblages which can be considered to be characteristic signatures of „Kachchh mainland‟ end member. The estuarine zone which is a subsink within the Rukmawati river basin, typically shows mixing of landward and offshore distributed sediments and as how the Kachchh mainland source is dominant in bedload sediments and Indus river source is dominant in suspension load sediments, which are getting transported eastwards into the inner Gulf of Kachchh through alongshore currents. DISTRIBUTION AND SPECIATION OF SELECTED HEAVY METALS IN THE SURFACE SEDIMENTS FROM AN ESTUARY IN COLEROON RIVER, EAST COAST OF INDIA Ramkumar T1, Anithamary I2, Venkatramanan S2, Gnanachandrasamy G2, S.Vasudevan 1,2 Department of Earth Sciences, Annamalai University, Annamalainagar- 608 002, India Corresponding author: tratrj@gmail.com Estuarine sediments are major reservoirs for the metals. Distribution and mobility of metals within estuaries depends strongly on their various chemical forms. Sediments of Coleroon estuary in the east coast of India have been analyzed for geochemical forms of trace metals Fe, Mn, and Zn by sequential leaching. A total of ten surface sediment samples were collected from selected locations during monsoon and summer season of the year 2010 covering mouth, estuarine and freshwater zones of the estuary. The results revealed that, the higher concentration of metals were associated with the residual phase compared to other phase followed by Fe-Mn oxide phase. The study indicates higher metal concentrations were observed at estuarine region where as lower levels were observed at mouth and freshwater zones. The concentrations of heavy metals in the sediments were as follows: Fe > Mn > Zn. The distribution of heavy metals in each species with respect to stations and seasons are discussed in the paper. TOPOLOGIC PROPERTIES OF DRAINAGE NETWORK ON THE MEGAFAN SURFACE AND ITS IMPLICATIONS FOR THE DEVELOPMENT OF MEGAFANS Arindam Misra#, Parthasarathi Ghosh**, Tapan Chakraborty** # Department of Geology, University of Calcutta, Kolkata 700019 Email: arindammisra999@gmail.com **Geological Studies Unit, Indian Statistical InstituteKolkata 700 108 Megafan is a huge fan like body with a low slope, radiating drainage and built exclusive by fluvial processes. In many cases, the channel network on the megafan surface is organised in a number of lobes and it is postulated that megafans grow through aggradation and relocation of these lobes. In this work we present a study of the contrasting channel patterns observed on the Kosi and Tista megafans and suggest a possible explanation for the differences. The network of paleo-channel traces on the lobe 2 of the Tista magafan is strongly radiating in character. The paleochannels bifurcate and diverge down the fan. The first order 57 IGCP 582: IIT Kanpur, January 2012 bifurcations give rise to major distributary channels close to the megafan apex. The subsequent bifurcations take place progressively down the megafan giving rise to a wider network of smaller splay channels in distal part of the megafan. The angle between the two branches immediately downstream of each bifurcation is high (~60°). The pattern of paleo and modern channels on the Kosi megafan is very similar between them and significantly different from that of the Tista megafan. The channel networks here are weakly radiating in character with mutual angle between any two branches comparatively lower (~30°) (Fig 1). Like Tista branching of the highest order channels in the Kosi megafan are confined in a narrow zone close to the apex. However unlike Tista, channel pattern on Kosi comprises networks of anastomsing channels. The proportion of marshes is also much higher in the Kosi megafan. The modern channels frequently end in the marshes and many smaller channels grow from the marshes and join the anastomosing network of channels. This gives rise to a mutually subparallel, locally discontinuous, low-divergence network of anastomosing channels on the megafan. The two megafans occurs side by side in a foreland basin setting, and both occur in a monsoonal climate regime. However, distinctive pattern of channel network within them and difference in relative proportion of marshes within them point to a difference in their formative mechanisms. We suggested that this difference is related to available accommodation space and sediment load. The Tista megafan has been abandoned and is being incised at present, probably due to lack of available accommodation space and/or decrease in sediment:water ratio. The Kosi megafan, on the other hand, is characterised by lower slope, much larger catchment area. Also the rate of convergence measured from GPS data is double in Kosi area (~20 mm/year) than that in the Tista area (~ 9 mm/year). The higher rate of convergence has probably resulted increased thrust loading and back tilting of the foreland sediment surface and thereby lowering of the fan surface slope. The lower gradient and possible higher sediment supply due to its larger catchment probably resulted in anastomosing channel pattern. Repeated formations of new channels from the marshes that join the channel network increases the number of channels in a segment and thereby reduce the divergence among the channels rendering them sub-parallel to each other. The combined effect of all these plausibly result in low-divergence, locally discontinuous, anastomosing pattern on Kosi megafan in contrast to the strongly radiating, braided channel pattern of the Tista megafan. Figure 1 58 IGCP 582: IIT Kanpur, January 2012 NATIONAL GEOMORPHOLOGICAL MAPPING IN INDIA AND ITS RELEVANCE TO RIVER BASIN RESEARCH AND MANAGEMENT – AN OVERVIEW Lalan Prasad Singh and V. Singa Raju Geological Survey of India, Southern Region, Hyderabad – 500 068 E-mail: lpsingh8@gmail.com The threats caused by hydrological phenomenon in densely populated river basins of India are becoming more and more serious, resulting in high damage consequences to the population and infrastructures. The occurrence of intense meteorological events is expected to increase further in response to rapid urbanisation and climatic changes. Therefore, it is important to develop a dynamic system for assessment of hazards after every major flood event so that it can be an essential component of developmental plans for river basins. Geomorphological mapping is fundamental to river basin management strategies such as preparation of hydrological hazard maps, which may become an obligatory tool for landuse planning in densely populated areas of larger river basins. However, the validity of key interpretations made from the resulting hazard maps are often constrained by the quality of geomorphological maps. Geological Survey of India (GSI) has published a geomorphological map on 1:2 million scales, which may not be suitable for such studies as it gives a very generalized depiction of landforms. In such small scale maps many critical landforms of smaller spatial extent are often merged with the surrounding landforms of larger spatial extent. It is therefore, imperative to have more detailed geomorphological maps of desired accuracy for credible research. The ongoing collaborative project of GSI and National Remote Sensing Centre (NRSC) for preparation of the National Geomorphological and Lineament Mapping (NGLM) of the whole country on 1:50,000 scale has the potential use for the kind of study as mentioned in the preceding section. For this project the geomorphological and lineament map of the country is being made by satellite image interpretation of multi-season Resourcesat-1 LISS-III data. In addition, ancillary datasets such as District Resource Map & Geological Map of GSI is being used to aid the image interpretation. SRTM and ASTER DEMS are also being used to derive hill-shaded maps which are then fused with the LISS III image for better delineation and mapping of landforms and lineaments. Ground truth collection is an integral part of the study which focuses on validation of the geomorphology and lineament maps prepared by image interpretation and on screen digitization. The end product in the form of a seamless geomorphological map of the country will be put on the portal of GSI and ISRO. A specific geomorphological legend have been developed for precise mapping based on recommendations of a number of geomorphologists from GSI, NRSC, Regional Remote Sensing Centres, academic institutions, etc. and feedback from a number of pilot projects done by GSI and NRSC has also been considered. The classification scheme adopted for the project is a hierarchical system which is a modification of the genetic classification. This is a three level classification scheme with the first level addressing the genetic aspect, the second level the broad geomorphic aspects and the third level the landform units. The legend has been imbedded in a customized tool NRC Geom in ArcGIS environment for error-free digitization and attribute data 59 IGCP 582: IIT Kanpur, January 2012 handling. The advantage of mapping in a GIS environment is that in addition to mapping it allows database management and attribute-based query so that any specific data required for a research can be retrieved from the database. The execution of the work is being done on the basis of a standard operating procedure (SOP) and a very stringent system of quality control has been implemented with involvement of experts at each level of execution. The product resulting from this collaborative programme will provide a base geomorhological and lineament map of the whole country which can be used for temporal assessment of hazards and vulnerability for strategic plans for river basin development and management. More specifically, the data will be in public domain and therefore the user community will be greatly benefited. THE SONE MEGAFAN AND THE POSSIBILITY OF ITS EXISTENCE IN THE MARGINAL PARTS OF GANGA BASIN IN INDIA Sudarsan Sahu Central Ground Water Board, MER, Lok Nayak Bhawan, Patna The Gangetic Plain in India serves excellent examples of (mega) fan deposits. The plain, lying between the rising Himalaya in the north, and the Indian craton in the south, forms one of the vast Quaternary alluvial tracts in the world. At the Himalayan mountain exit, many rivers have generated prominent megafans; from east to west lye the Kosi, the Gandak, the Ghaghra, the Sarda and the Yamuna-Ganga megafans. In contrast, the craton-origin rivers are not reported to form „fan‟ at the peninsular foot-hills in Ganga plain. The present work explores the existence of the Sone megafan in such an environment, which has remained largely unrecognized and unattended (Fig 1). Him Delhi ala PZ - Piedmont Zone CAP - Central Alluvial Plain ya Patna MAP - Marginal Alluvial Plain - Major Lineaments (faults) in Ganga Basin H I M Delh Ridg i-Hardw a e r Nainital Study Area A A Y ak R. Ghaghra R. CAP Allahabad MAP Varanasi MAP Vindhyan Highlands Bundelkhand Massif R. . Satpura massif 0 PENINSULAR INDIA 60 R. ne una R Patna Kosi So Y am rs nd . Mu Ri nge dg rSa e R Vi Ri ndh dg ya n e ga Fa Ri izab dg ad e an ha Sone megafan Ga a PZ G Delhi A L 100 200 km IGCP 582: IIT Kanpur, January 2012 Figure 1: The Ganga Basin with various structural and other geomorphic features along with the location of Sone megafan. The Sone River is the largest peninsular drainage in respect of discharge (10760 m3/s ) that it conveys to the Ganga and it has remained shifting in character (Fig 2) unlike to the stable and deeply incised other craton-origin rivers (Ken, Betwa, Chambal) lying at the western parts of the basin. The river, in its about 200 Km traverse in the Ganga Plain, displays highly braided character with considerable width (2-5 Km). Since Late Pleistocene, the river has remained largely seasonal with high fluctuation in discharge levels. The river has formed a megafan, which is aerially extensive and covers ~22, 000 Km2, larger than the well known Kosi megafan in the Ganga Basin. Its location in the marginal alluvial set-up at the northern peninsular foot-hills of the basin and extending well into the central parts (north to the active Ganga River) is unique world over. In contrast to the general narrow nature, the Marginal Alluvial Plain (MAP) lying south to the axial drainages (the rivers Yamuna in the west and Ganga in the east) at the distal parts of the basin is widest in the Sone megafan area. The fan area is traversed by few of the most active basement faults in the region, which have caused subsidence in the western/northwestern parts with respect to the lines of deformation. This has primarily helped in space creation for sediment accommodation, other than evolving the fan architecture and geometry. Within the entire area, there exist stacked columns of multiple (fine to very coarse-brownish yellow) sand layers down to tens to hundreds of meters with few clay intercalations. These craton-derived sediments in the Sone-Ganga alluvial tract are followed upward by Himalayan-derived finer sediments, which constitute hardly 10-15 % of the entire borehole lithology in the area. This has happened due to southward advent of Ganga and its entrenchment on the megafan surface. From the distribution pattern of its palaeo-channels, it is evident that the river was joining the axial drainage Ganga at different points spreading over a distance of about ~ 200 km. All the abandoned channels of Sone are broadly diverging in character. However, unlike to most of the fan-forming rivers, the Sone does not radiate always from the apex or near to apex of the megafan. Some of the palaeo-channels indicate avulsion somewhere in the middle reaches of the river. From the distribution pattern of palaeo-channels (Fig 2), it is anticipated that in the initial phases of the fan building, autocyclic processes such as river bed building (sedimentologic) in a strong monsoonal set-up during early to middle parts of Late Pleistocene might have controlled the channel movement (avulsion). But, later on, allogenic (tectonic) factors have largely responsible for the channel avulsions. 61 IGCPCHANGES 582: INIIT January 2012 RIVER COURSE OF SONE THEKanpur, N Li n R. m ag hr a en t R. Chapra R. Gandak Ganga Gh ea Babura Ara X (Bhojpur) Jagdispur II na sR . R. Ka rm na sa Koilwar PF W New Bhojpur a or Th R. Buxar 20 0 Fatuha Barh IIIA Y 40 km Scale Mokama Ba I Bishunpur Sandes Hajipur XII IX Khagaul XI Maner VIII VII Patna V Bihta IV VI Barkagaon F BK VIA So ne R. Nasriganj P Arwal Nalanda VI III X Daudnagar . nR pu un F INDEX EP Old beds of Sone River Dehri Old bed of Ganga River Indrapuri barrage Present river channels Rohtas Garh Gaya Lineament Japla Fault Peninsular exposure Figure 2: The active Sone River along with the traces of palaeo-channels. SHALLOW SUBSURFACE STRATIGRAPHY OF MEGAFANS IN NORTH BIHAR PLAINS USING ELECTRICAL RESISTIVITY SOUNDING AND BOREHOLE DATA Jawed Ahmad, Gaurav Kumar, Guillaume Morin and R. Sinha Department of Civil Engineering, Indian Institute of Technology Kanpur Centre de Recherches Pétrographiques et Géochimiques, CNRS Nancy, France The Kosi and Gandak are two important Himalayan tributaries of the Ganga River which drain parts of Nepal and north Bihar plains in India. With a large hinterland in the Nepal Himalaya, both these rivers have generated megafans in the plains over the Quaternary time scale. Both these rivers are known to be highly dynamic and sedimentcharged. Although there has been some work done on the geomorphology of the megafans, there is almost no data on the sub-surface stratigraphy of these megafans. A few conceptual models have suggested that these magafans may have produced thick sand sheets over the Late Quaternary period but these ideas have remained speculative and there is no data on the size and dimensions of these sand bodies. We have analysed the borehole data for the eastern part of the Kosi mega fan obtained from the Geological Survey of India and have also carried out electrical resistivity soundings across the megafan to generate first order lithostratigraphic data for the upper ~100 meters of the strata. Based on the shallow borehole data, we have generated profiles along several transects which show large variation of lithology with depth and space. Some of the transects show more than 20 meters thick sand bodies which are interpreted as channel deposits of the paleochannels of the Kosi river. From the electrical resistivity sounding data, we record resistivity variation from 20 ohm-m to 800 ohm-m. The most common values range between 25 and 350 ohm-m which are very close to the usual values of sandy 62 IGCP 582: IIT Kanpur, January 2012 to clayey (30-215 ohm-m) alluvial deposits. In general, the electrical resistivity data suggest the occurrence of 30-40 meters thick sand bodies buried below thin silty cover. Many of these locations are close to the paleochannels mapped on the satellite images. During the field surveys, shallow (<2 m) excavated sections at some locations showed very thin soil (15 cm) layer underlain by medium to coarse sand with well-developed cross stratifications. Electrical resistivity data is currently being analysed and will be integrated with the borehole data to generate detailed alluvial stratigraphy and to understand avulsion dynamics over longer time scale. LANDSCAPE EVOLUTION AND GEOMORPHOLOGY OF THE TANGTSE RIVER VALLEY (LADAKH), NW INDIAN HIMALAYA Binita Phartiyala, Randheer Singha*, Girish Ch. Kothyarib & Anupam Sharmaa a Birbal Sahni Institute of Palaeobotany, 53-University Road, Lucknow-226 007, UP., India b Institute of Seismological Research, Raisan, Gandhinagar- 382382009, Gujarat, India *Corresponding author: Randheer Singh; email address: randheer.singh@gmail.com The River Tangtse a tributary of River Shyok (Shyok-tributary of River Indus) occupies a 94.18 km long course in the Karakoraum Fault (KF) zone which covers almost 2170 sq km basin area in Indian Trans Himalaya. In this area the strike-slip KF bifurcates in two strands viz., the SW Tangtse Strand and NE Pangong Strand (Rutter, 2007). An east ward tilting in Pangong Tso area near Chusul is seen due to the vertical uplift of pressure ridge in Quaternary time observed in the Pangong strand. Presence of strath terraces (28m), offset of streams (200-400m); wide valley filled with debris flow and fluvio-lacustrine sediments at 4280m elevation, all indicate active nature of KF in the area. The rate of uplift is very high near Tangtse (34.02427N; 78.17577E). Due to lateral movement along this fault the river incised the granitic rock shifting towards west. In due course of time the colluvial material filled the incised valleys indicating a fast rate of tectonic uplift. In the Tangtse strand the valley become very wide and completely filled with alluvial fan and debris flow deposits. West heading fault scarp is visible within the fan clearly seen in the LISS-III satellite data. Three levels of unpaired strath terraces surfaces are seen in the left bank of Tangtse valley near Durbuk, indicating flood drainage and fluvial incision. The River Tangtse flows in a very narrow gorge (nearly 300-400m) before its joining with the River Shyok, cutting across the KF. These deposits are around 50 m thick and five massive yellow clay units lie within the fluvial sands units. Fluvio-lacustrine deposits are very common in the lower Tangtse valley. The lowermost unit has been assigned an age of ~13ka (Singh, 2008). These deposits are overlain by debris all along the valley downstream. The presence of a lake system in the Late Quaternary times is attributed to favorable water supply and good climatic conditions. Earthquake related soft sediment deformational structures are well preserved within the sediments. Open folds are seen within the fluvial sediment, formed due to continuous compression. In the lacustrine sediments a tight to isoclinal fold (plunging 200 towards east), 3.45 m high is seen. Small scale reverse faulting has also been observed within the clay units. Presence of such a huge deformation within the sediments as well as the other indications mentioned above all reflects active nature of KF (both Pangong and Tangtse strands) and interplay of climate-tectonics in the entire region during the Late Quaternary period. 63 IGCP 582: IIT Kanpur, January 2012 EVOLUTION OF SRINAGAR (GARHWAL) VALLEY LANDFORMS: RESPONSE OF ALAKNANDA RIVER TO CLIMATE CHANGE OR RESULT OF INTERACTION BETWEEN MAIN RIVER (ALAKNANDA RIVER) AND LOCAL STREAMS Rahul Devrani1 and Vimal Singh* Department of Geology, Centre of Advanced Study, University of Delhi, Delhi - 110007 *Corresponding author - vimalgeo@gmail.com The present study investigates the depositional landforms of the Srinagar valley along the Alaknanda River and reviews existing literature under the light of new observations. Terraces are the most significant feature in the Srinagar valley. Previous workers (Khan et al., 1982; Sati et al., 2007; Sundriyal et al., 2007; Ray and Srivastava, 2010) have identified six levels of terraces on the northern bank of the Alaknanda River, whereas on the southern bank these terraces are still unclassified. These terraces have been identified as valley fill terraces based on their composition (Ray and Srivastva, 2010; Juyal et al., 2010). Recently two models (Juyal et al., 2010; Ray and Srivastva, 2010) have been proposed for the evolution of landforms in the Srinagar valley on the basis of the ages of sediments composing terraces. The model given by Juyal et al., (2010) states that there were two phases of aggradation in the Srinagar valley, separated by a phase of uplift. According to the model older aggradation event started ca. 18 ka whereas younger aggradation event occurred between 15 to 8 ka after which gradual decline in monsoon lead to incision by the Alaknanda River resulting in the formation of terraces (Juyal et al., 2010). On the other hand model proposed by Ray and Srivastava (2010) suggests that there were two phases of aggradation; older between 49 ka to 25 ka and younger between 18 ka to 11 ka. It was also suggested that the incision started after 11 ka due to increase in precipitation and fluvial discharge. Both the studies (Juyal et al., 2010; Ray and Srivastava, 2010) have investigated Alaknanda River sediments of the Srinagar valley, yet their models disagree with each other. Most important disagreement in the models is that of the timing of incision. The present study identifies some important parameters that have been ignored in the previous studies and surmises that the disagreement in the models could have resulted due to ignoring of some parameters. The present study shows that a thick sequence of local stream deposits is present beneath the Alaknanda River deposits. It also suggests that the terraces in the Srinagar valley are fan-cut terraces developed over the surface of an alluvial fan (we call the fan as Choras fan) deposited by the local streams. Moreover, thick sequence of Alaknanda River deposits upstream of the Choras fan indicates aggradation could be due to blocking of its course by the local stream deposits. It is therefore, proposed that a comprehensive understanding of the interaction between the Alaknanda River and the local streams is required together with the understanding of effect of monsoon on the local streams, in order to recognize the evolution of landforms in the Srinagar valley. Further, tectonics in the area also indicates towards its important role in the evolution of the landforms. A model incorporating both the results of previous studies and new observations has been proposed to explain the evolution of landforms in the Srinagar valley. 64 IGCP 582: IIT Kanpur, January 2012 SHRINKING WETLANDS IN WEST BENGAL: A CASE STUDY FROM HOOGLYDAMODAR INTERFLUVE AND EAST KOLKATA WETLAND AREA Arindam Mishra, ShantanuSarkar, SayanSinha, TapanChakraborty Geological Studies Unit, Indian Statistical Institute, Kolkata 700108 Fresh water wetlands are naturally occurring areas covered ephemerally or perennially with water, typified by formation of hydromorphic soil, and it can sustain a typical suite of flora and fauna. Besides being biodiversity hotspots, wetlands are most important region of terrestrial primary production and terrestrial oxygen sources, and are known to play important role in groundwater recharge, water storage, flood control, reduction of soil erosion and detoxifying surface water from many of its toxic and metal ion concentrations (Greb et al., 2006, GSA Sp. Publ. 399, p.1-40). The present study covers about 7300 km2 in the Hoogly-Damodar Interfluve area and about 40 km2 in the East Kolkata Wetland (EKW) along the eastern fringe of the city of Kolkata. We have used temporal succession of LANDSAT data between 1999 and 2010, along with SRTM DEM data and Google Earth images to study the geomorphic features of the study areas. The satellite images were processed through ERDAS IMAGINE for supervised classification to detect the wetlands. This was followed by extensive ground checking to validate the image analysis and document relevant field features. SRTM section across in the area between the Damodar-Darakeswar River in the west and Hoogly River in the east is a topographically low-lying area with depressions up to 13 m deep. The area dominantly comprises of interfluves channels (like Saraswati R., now completely covered up by anthropogenic activity), levees of the main channels and large bodies of permanently waterlogged marshes. The bottom of the depressed areas lies close to the mean sea level or very close to the water level in the Hoogly River. In the field the 2.5 m thick dug sections near Dankuni Railway Station (22°40‟06.06”N 88°17‟49.74” E) show multiple layers of grey hydromorphic soils and peat layers alternating with silty fine sand indicating long standing position of these areas close to water table. Silty sand layers probably denote periodic records of flood from flanking interfluves channels. Based on micro-topographic analysis, shallow boreholes, resistivity logs Geological Survey of India has also reported thick units of carbonaceous mud, coaly layers, peats and extensive wetlands in Dankuni-Hindmotor area (GSI reports UE 4396 of 1973 and UE 13326 of 2000). Ground investigations and Google Earth images indicate that filling up of more than 2 m deep water bodies continues unabated in this region. In order to estimate the loss of wetlands, spatial coverage in the imageries were divided into 48 different classes based on the tonal character and texture of the images. These classes can be broadly grouped into 4 categories namely the urban habitat, the rural habitat, agricultural fields, rivers-waterbodies-wetlands. Supervised classification of a temporal succession of LANDSAT images using these broad classes was performed using the standard methods available in ERDAS software. Analysis of the satellite image of 2010 shows that of this 17.81% of the land is covered by the wetlands and water bodies, while agricultural land comprises 34.85%, urban and rural habitation comprises 14.34 and 32.99% of the area respectively. Similar analysis carried on LANDSAT image of 1999 shows that the area of wetland in the same region was 22.79%, and agricultural land, urban habitation and rural habitation comprises 22.66%, 12.43% and 42.11%. Thus a conservative estimate of change indicates that during this period we 65 IGCP 582: IIT Kanpur, January 2012 have loosed 43.684 km2 (or 4368.4 hectare) of wetland. This loss is about 21.74% of the wetland we had in this area in the year 1999. Similar investigation using Google Earth historical images and satellite images and ground check in the East Kolkata Wetland (EKW), shows that between 2002 and 2010, 718 hectare of wetland (18.04%) has been filled up in the EKW. It is noteworthy that EKW was declared a Ramsar Site in the year 2002. The presence of these large wetlands has remained crucial in refreshing the air quality, water quality and maintaining the groundwater levels of the metropolitan city of Kolkata. However, notwithstanding the fact that gound water table of the city is declining at a alarming rate of 0.11 m/year over the last decade. Further as these are natural depressed lands they can retain and store a huge volume of water, thus controlling the surface water discharge during intense monsoonal precipitation in Gangetic West Bengal. During the intense monsoonal precipitation water retention property of the wetlands play a very important role in moderating flood discharge, particularly to Damodar River and its tributaries. Although the general importance of wetland hardly needs any elaboration, and India became a signatory to Ramsar Convention in eighties, unlike the coastal zone management rules, there is a lack of comprehensive legislation to protect the wetlands. GIS-BASED MORPHOMETRIC ANALYSIS OF TONS RIVER BASIN WITH SPECIAL REFERENCE TO TECTONIC UPLIFTMENT Arpita Pankaj,1* Pankaj Kumar2 and Ajai Mishra3 Geological Survey of India, Northern region, Lucknow 3 Department of Geology, Centre of Advance Study, Lucknow University * E-mail: pankaj.arpita@gmail.com 1, 2 Evaluation of the morphometric parameters requires preparation of drainage map, contour map, ordering of the various streams and measurements of catchment area, perimeter, relative relief, relief ratio, length of drainage channels, drainage density, drainage frequency, bifurcation ratio, texture ratio, circulatory ratio, elongation ratio, ruggedness number, from factor and constant channel maintenance, which helps to understand the nature of drainage basin. The present study involves the Geographic Information System (GIS) analysis techniques to evaluate and compare linear, relief and aerial morphometry of the seven sub watersheds of Tons River (tributary of the Yamuna River) with special reference to tectonic upliftment, for future development & planning of the watershed. Nera Nadi, Sainj or Minas River, Shalon Gad, Pabar River, Rupin Nadi, Supin Nadi and Harkidun Gad are the seven major sub-watersheds of the Tons River basin. All the sub-watersheds are basically of 5th to 7th order. Drainage pattern are mainly sub dendritic to dendritic. The drainage pattern of the Tons River basin is mainly structurally controlled and the area is characterized by high to vey high relief. The asymmetric factor indicates that the tectonic rotation is upward to the right side in case of Pabar River, Sainj or Minas River and Rupin Nadi sub-watershed and in case of Nera Nadi, Shalon Gad, Harkidun Gad and Supin Nadi sub-watershed the tectonic rotation is down to the right side of the drainage basin. 66 IGCP 582: IIT Kanpur, January 2012 LANDSCAPE EVOLUTION AND MORPHOLOGICAL CHARACTERIZATION OF DRAINAGE NETWORK OF CORBYN RIVULET, SOUTH ANDAMAN ISLANDS, INDIA – A GROUND PENETRATING RADAR (GPR) AND REMOTE SENSING STUDY Shrikant Maury* and S. Balaji Department of Coastal Disaster Management, Pondicherry University, Port Blair, Andaman and Nicobar Islands India *Email: chriss86@mail.ru The drainage network of Corbyn Rivulet has most diverse geo-morphological characterizations among the other drainage systems of the South Andaman Islands. This drainage covers a catchment area of 12.04 km2 and geographically ambit between 11°36‟00‟‟ to 11°39' 30'' North latitudes and 92° 42‟30‟‟ to 92°45‟00‟‟ East longitudes. The major geomorphological feature of the rivulet dominated by trellis and dendritic drainage pattern, and the landscape of the area has moderately high hills, intermontane valleys including coastal tract. The major geological rock settings of this area are pillow basalt, turbidites, conglomerates and grits which structurally represent the area is highly deformed and stressed due to the presence of faults and fractures. Investigations were carried out by using the Ground Penetrating Radar (GPR) for the studying of subsurface information of different geological settings. To optimize the GPR signal performance on-to a much depth of the fault and fracture the GPR incorporated by 15 MHz center frequency antenna and this assemblage of antenna was able to penetrate more than 60 meters depth in different geological sections of fractured rocks and for the ground validate different bore well lithographs were incorporated. Further, visual interpretation of geomorphological features of the rivulet terrine such as drainage pattern, lineaments, fault and fold etc. accomplished by high resolution satellite imagery on 1:27,000 scale. An evaluation on the contemporary issues related to water resources and their vulnerability by human intervention and other hydrological problems also have been undertaken and discussed. Finally, culmination of various problems and their management strategies related to Corbyn Rivulet for the sustainable island environment were designed and proposed. GRAIN SIZE AND GEOCHEMICAL ANALYSIS OF THE SEDIMENTS OF THE BRAHMAPUTRA RIVER AND FIVE OF ITS TRIBUTARIES Handique S and Senapati N Environmental Science Department, Tezpur University Major ions composition (Ca2+ , Mg2+ , Na+ , K+ ,Cl- , NO3-, SO42-), heavy metals(Cd, Cu, Fe, Pb), Total organic carbon (TOC) and the grain size distribution of bank sediments in the Brahmaputra and five of its tributaries have been studied to understand the geochemistry of the sediments and contribution of the tributaries to the main channel. River sediments were sampled at four locations in the Brahmaputra River at Siang, Dibrugarh, Sivasagar and Tezpur and five of its tributaries at Dikhow, Disang, Dhansiri, Jiabharali and Burhidihing. Some differences were found between the main channel and the tributaries which may be attributed to their origin. The results show that the Brahmaputra samples are slightly more alkaline than the tributaries.Fe was found to be in much higher concentration than other heavy metals and showed a positive 67 IGCP 582: IIT Kanpur, January 2012 correlation with the total organic carbon. The grain size analysis shows that the south bank tributaries had more silt-clay fraction than the north bank tributaries. The greater concentration of heavy metals in some tributaries shows the association of smaller grain size fractions (siltclay) of the sediments with heavy metals due to greater surface area to volume ratio. ELEMENTAL MOBILITY DURING WEATHERING OF THE GANGA ALLUVIAL PLAIN: A CASE STUDY OF THE GOMATI RIVER, NORTHERN INDIA Rohit Kuvar1, Sandeep Singh2, A. K. Choudhary3 and Munendra Singh1 1 Department of Geology, University of Lucknow, Lucknow-226007, India 2 Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee – 247667, India 3 Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee, India The elemental signature of river water characterizes the chemical weathering processes of a drainage basin. The abundance of elements in river water depends on their concentrations in the upper continental crust and mobility during weathering. Elemental mobility in river water is defined as a ratio of dissolved concentration and upper continental crust concentration normalised to the value for sodium. The classification of element mobility comprises highly mobile, moderately mobile, non-mobile and immobile elements. In northern part of the Indian sub-continent, the Ganga Alluvial Plain is an outstanding geographical region due to its low elevation, low relief, high fertility and high human population density. Geologically, it is made-up of interlayered 1-2 m thick fine sand and silty mud deposits showing extensive discontinuous calcrete horizons. Rivers of the plain are the major pathways to transport weathering products both in particulate and dissolved phases to the Ganga River. Weathering processes of the alluvial plain are largely concerned with the monsoon season and alluvial lithology, and become intensive due to large temperature variation (5-40 ˚C) in the winter and summer seasons. The Gomati River, a tributary of the Ganga River, drains about ~ 30, 000 km2 area of the plain. In the present study, twelve water samples were collected from the Gomati River at Chandwak (upstream of confluence with the Ganga River) during the monsoon season of June- September, 2009. All water samples were analysed by Inductively Coupled Plasma-Mass Spectrophotometer for their dissolved major and trace elements concentration to assess the elemental mobility during chemical weathering of the Ganga Alluvial Plain. The average dissolved concentration of elements in the Gomati River water during the monsoon season is Al (12.4 ppm), Fe (4.6 ppm), Si (4.5 ppm), Mg (7.7 ppm), Na (13.4 ppm), Ca (4.6 ppm), K (2.5 ppm), Mn (238 ppb), Sr (206 ppb), P (192 ppb), Ti (133 ppb), Ba (119 ppb), Se (102 ppb), B (42.6 ppb), Zn (30.6 ppb), Rb (22.5 ppb), V (13.7 ppb), Cu (12.8 ppb), Ni (12.3 ppb), Cr (9.8 ppb), Pb (8.96 ppb), Co (4.4 ppb), As (2.2 ppb), Cd (1.97 ppb), Mo (1.4 ppb) and Zr (0.044 ppb). The highly mobile elements having mobility indexes greater than that of Na comprise Cd, B, Se, As, Mo, Ni, Sr, Mg and Cu. The moderately mobile elements include Pb, Co, Zn, Mn, Cr, P, V, Ba, Rb, Al, Ca, Fe, and K. These elements have mobility indexes ~10 times less than that of Na. The non-mobile elements are Ti and Si with mobility index 10-100 times less than that of Na. The immobile element includes Zr, with mobility indexes more than 100 times lower than that of Na. The present study provide valuable information on the chemical 68 IGCP 582: IIT Kanpur, January 2012 weathering processes that control the distribution of major and trace elements in river water and global cycling of elements. GEOCHEMISTRY AND WEATHERING HISTORY OF BURIED RIVER SEDIMENTS FROM GHAGGAR PLAINS, NW INDIA Manu Rastogi, Ajit Singh, Debajyoti Paul, and Rajiv Sinha Department of Civil Engineering, Indian Institute of Technology Kanpur, India The Ghaggar River, originating from Himalaya foothills, drains through parts of Haryana and Rajasthan in NW India. A large part of the course of this ephemeral river currently occupies the paleo-valley of a major river channel sourced in the Himalaya. However, the subsurface existence of this postulated palaeochannel has been debatable. The on-going study on subsurface existence of the buried channel involves detailed sedimentological and geochemical studies on multiple drill cores, ~ 40 m deep, at several transects across the paleo-valley. Here we present geochemical data (clay mineralogy, and major and trace element abundances) on one of the drill cores (GS-11, 45 m deep, 29.47°N and 74.13°E) located near Kalibangan archaeological site, NW India. Detailed core logging reveals presence of ~25-30m thick micaceous, coarse to medium sand bodies of fluvial origin at variable depths below ~4m. Particle size analysis (n=16) shows -14% silt (4that the sediments are sandy to sandy clay loam with 552 = 0.75) with and 2sand. X-ray Diffraction (XRD) patterns of bulk sediments (n=16) reveal presence of quartz (5080%), feldspar (20-50%), and mica (7-30%), with mica being absent in aeolian sand below depth of 38m. XRD data of clay-sized fractions (air-dried, heated, and ethylene-gycolated samples) show illite abundance to be inversely correlated with kaolinite content, presence of smectite only in few samples, and absence of chlorite. Distribution of clay minerals with depth suggests variable environmental conditions with time: abundant illite could have formed in cool and dry climate whereas kaolinite in hot and humid climate and poorly-drained conditions. XRF data of bulk sediments show positive linear correlation (R2> 0.8) of Al2O3 (10-14 wt %) vs. Fe2O3 (1.7-4 wt%), K2O (1.8-3.9 wt%), MgO (1-4.3%) and TiO2 (0.3-0.9 wt%), Ba (270-550ppm) and a negative linear correlation vs. SiO2 (60-80 wt%). Rb/Sr ratio of alluvial sand (>0.4-0.5) is distinct compared to that of aeolian sand (<0.4). Zr/Nb ratio is greater than 15 for sediments shallower than 23m whereas the ratio is less than 12 for deeper samples, suggesting a major change in sediment provenance for these sediments. Ba/Sr ratio varies in a restricted range with depth except for two distinct excursions (at 29 and 36 m depth) suggesting strong leaching of Sr. The chemical index of alteration (CIA, molar ratio of 100×Al2O3/Al2O3+K2O+Na2O) varies in the range 35-60, with the lower values (~ 40) typical of basic igneous rocks and higher values (~60) typical of recycled sediments rich in clay. Down core variation in molar ratio of TiO2/Al2O3, a provenance indicator, in the range (0.04-0.08), suggests variation in sediment source. Data presented here aided by OSL age data is likely to provide insights as to how large sedimentary basins such as the one represented by the„buried‟ channel in the Ghaggar plains werefilled up over Late Quaternary periodin response to climate change. 69