Page 1. The 3rd International Conference on Water Resources and Arid Environments (2008) and the ... more Page 1. The 3rd International Conference on Water Resources and Arid Environments (2008) and the 1st Arab Water Forum Remote Sensing and GIS in estimating Groundwater Balance in semi-arid regions Haris H. Khan, Aadil ...
Page 1. The 3rd International Conference on Water Resources and Arid Environments (2008) and the ... more Page 1. The 3rd International Conference on Water Resources and Arid Environments (2008) and the 1st Arab Water Forum Remote Sensing and GIS in estimating Groundwater Balance in semi-arid regions Haris H. Khan, Aadil ...
A modified DRASTIC model in a geographic information system (GIS) environment coupled with an inf... more A modified DRASTIC model in a geographic information system (GIS) environment coupled with an information-analytic technique called ‘rough sets’ is used to understand the aquifer vulnerability characteristics of a segment of the lower Kali watershed in western Uttar Pradesh, India. Since the region is a flat plain, topography (T) is removed as a potential control. Other parameters are the same as in DRASTIC, hence the new model is termed as DRASIC. The rough set technique is employed to provide insight into the relative vulnerabilities of different administrative units (blocks) within the study area. Using rough sets, three important factors are computed: strength, certainty and coverage. Strength indicates how the vulnerability characteristics vary in the entire area, certainty gives the relative fractions of low, medium and high vulnerability regions within a particular block, and coverage computes the percentage of a particular vulnerability state in each block. The purpose of the work is to demonstrate the utility of this integrated approach in classifying different administrative blocks in the study area according to their aquifer vulnerability characteristics. This approach is particularly useful for block-level planning and decision making for sustainable management of groundwater resources.
This study attempts to simulate the spatial heterogeneity of infiltration in a drainage basin usi... more This study attempts to simulate the spatial heterogeneity of infiltration in a drainage basin using digital elevation models. Infiltration capacity is one of the controlling factors in the formation of stream channels. Channel formation is also a function of the slope and the contributing area. Natural stream channels, if properly graded and adjusted to the present climate, reflect the interactions of local slope, contributing area, and permeability of surface materials. Channel networks can be delineated from a Digital Elevation Model (DEM) using a variety of algorithms using different thresholds for channel initiation. These algorithms delineate a channel network on the basis of local slope, curvature, and contributing area, without considering the permeability of surface cover. Hence, the difference in the structure of the two drainage networks, i.e. the surveyed drainage network obtained from field observation and the simulated network generated from the DEM, is indicative of the spatial heterogeneities in the permeability of the surface cover as shown in this paper. Spatially variable drainage density maps corresponding to the two networks have been used here to obtain normalized difference maps that characterize the potential infiltration anomalies within the catchment. The simulated spatial pattern is compared with the actual infiltration measurements in the field using infiltration tests. Strong positive correlation between the observed and modeled infiltration confirms the effectiveness of this technique in the rapid assessment of potential infiltration variability.
In this study, the hydrodynamics of lower Ganges basin in India has been monitored using radar al... more In this study, the hydrodynamics of lower Ganges basin in India has been monitored using radar altimetry data from environmental satellite (ENVISAT) mission and microgravity data from the Gravity Recovery and Climate Experiment (GRACE) mission. River stage time series have been constructed for different virtual stations on the lower Ganges. Time series for the integrated water volume changes from microgravity measurements have also been constructed to characterize the seasonal and interannual fluctuation patterns in water storage and flux. The ENVISAT dataset indicates an average seasonal river stage fluctuation of 8 m in the lower Ganges River. The GRACE dataset reveals a seasonal fluctuation ranging from 0.18 to 0.40 m in the vertically integrated total water storage in the lower Ganges basin. The two independent datasets show broad similarity in the lower Ganges basin and outline the importance of space-based techniques for monitoring continental water resources.
Groundwater flow modelling and mass transport simulation were carried out to determine the Nitrat... more Groundwater flow modelling and mass transport simulation were carried out to determine the Nitrate and Total Dissolved Solid (TDS) migration within the shallow unconfined aquifer of the upper Anga’a river watershed of Yaoundé city, Cameroon. The MODFLOW code calibrated for February 2008 groundwater levels was used to simulate the steady state distribution of hydraulic head. Simulated hydraulic heads were similar to observed values along the watershed in model validation. The nitrate and TDS transport were described by the convection equation and solved using MT3D. The pollutant fate andtransport model (MT3D) reproduced the spatial pattern of observed nitrate concentrations in model calibration and validation. Groundwater and plume velocities were 0.26 and 0.21 m per day respectively. Simulating the contaminant migration from the recharge area shows that the plume may take more than 50 years travel time to reach the central part of the basin from which decision analysis can be made for generating key criteria to secure any water quality from contamination. The application of groundwater modelling tool in this study has shown excellent perspectives for monitoring and protecting aquifer system from spatial and temporal pollutant migration that addresses the concern of changing natural groundwater recharge, population growth and economic development in the study region.
This study attempts to assess the influence of changing land-use patterns on the groundwater qual... more This study attempts to assess the influence of changing land-use patterns on the groundwater quality of the hard rock aquifer system in the Maheshwaram watershed, near Hyderabad, India. The study area is a rapidly urbanizing region with land development progressing at a fast pace. To study the impact of this rapid urbanization and overall land-use transition, a groundwater quality index (GQI) was prepared within a geographical information system (GIS). The GQI integrates the different water quality parameters to give a final index value that can be used for spatio-temporal comparisons. The land-use transitions were closely monitored from 2003 to 2008 using multispectral satellite images. The land-use pattern has changed drastically with an increase in the built-up area at the expense of other land uses. The analysis reveals a rapid deterioration of groundwater quality related mainly to the increase in built-up land with unsewered sanitation and poultry farms. Seasonal variability of the groundwater quality was also assessed. Mean GQI decreased from 84.16 to 83.26 over a period of 5 years from 2003 to 2008, while seasonal variability of water quality increased. GQI and Seasonal Variability of water quality were integrated in GIS to yield a groundwater sustainability map, in terms of water quality. Zones of sustainable and unsustainable groundwater use were demarcated for better decision making related to municipal land allotment in this rapidly urbanizing region.
Page 1. The 3rd International Conference on Water Resources and Arid Environments (2008) and the ... more Page 1. The 3rd International Conference on Water Resources and Arid Environments (2008) and the 1st Arab Water Forum Remote Sensing and GIS in estimating Groundwater Balance in semi-arid regions Haris H. Khan, Aadil ...
Page 1. The 3rd International Conference on Water Resources and Arid Environments (2008) and the ... more Page 1. The 3rd International Conference on Water Resources and Arid Environments (2008) and the 1st Arab Water Forum Remote Sensing and GIS in estimating Groundwater Balance in semi-arid regions Haris H. Khan, Aadil ...
A modified DRASTIC model in a geographic information system (GIS) environment coupled with an inf... more A modified DRASTIC model in a geographic information system (GIS) environment coupled with an information-analytic technique called ‘rough sets’ is used to understand the aquifer vulnerability characteristics of a segment of the lower Kali watershed in western Uttar Pradesh, India. Since the region is a flat plain, topography (T) is removed as a potential control. Other parameters are the same as in DRASTIC, hence the new model is termed as DRASIC. The rough set technique is employed to provide insight into the relative vulnerabilities of different administrative units (blocks) within the study area. Using rough sets, three important factors are computed: strength, certainty and coverage. Strength indicates how the vulnerability characteristics vary in the entire area, certainty gives the relative fractions of low, medium and high vulnerability regions within a particular block, and coverage computes the percentage of a particular vulnerability state in each block. The purpose of the work is to demonstrate the utility of this integrated approach in classifying different administrative blocks in the study area according to their aquifer vulnerability characteristics. This approach is particularly useful for block-level planning and decision making for sustainable management of groundwater resources.
This study attempts to simulate the spatial heterogeneity of infiltration in a drainage basin usi... more This study attempts to simulate the spatial heterogeneity of infiltration in a drainage basin using digital elevation models. Infiltration capacity is one of the controlling factors in the formation of stream channels. Channel formation is also a function of the slope and the contributing area. Natural stream channels, if properly graded and adjusted to the present climate, reflect the interactions of local slope, contributing area, and permeability of surface materials. Channel networks can be delineated from a Digital Elevation Model (DEM) using a variety of algorithms using different thresholds for channel initiation. These algorithms delineate a channel network on the basis of local slope, curvature, and contributing area, without considering the permeability of surface cover. Hence, the difference in the structure of the two drainage networks, i.e. the surveyed drainage network obtained from field observation and the simulated network generated from the DEM, is indicative of the spatial heterogeneities in the permeability of the surface cover as shown in this paper. Spatially variable drainage density maps corresponding to the two networks have been used here to obtain normalized difference maps that characterize the potential infiltration anomalies within the catchment. The simulated spatial pattern is compared with the actual infiltration measurements in the field using infiltration tests. Strong positive correlation between the observed and modeled infiltration confirms the effectiveness of this technique in the rapid assessment of potential infiltration variability.
In this study, the hydrodynamics of lower Ganges basin in India has been monitored using radar al... more In this study, the hydrodynamics of lower Ganges basin in India has been monitored using radar altimetry data from environmental satellite (ENVISAT) mission and microgravity data from the Gravity Recovery and Climate Experiment (GRACE) mission. River stage time series have been constructed for different virtual stations on the lower Ganges. Time series for the integrated water volume changes from microgravity measurements have also been constructed to characterize the seasonal and interannual fluctuation patterns in water storage and flux. The ENVISAT dataset indicates an average seasonal river stage fluctuation of 8 m in the lower Ganges River. The GRACE dataset reveals a seasonal fluctuation ranging from 0.18 to 0.40 m in the vertically integrated total water storage in the lower Ganges basin. The two independent datasets show broad similarity in the lower Ganges basin and outline the importance of space-based techniques for monitoring continental water resources.
Groundwater flow modelling and mass transport simulation were carried out to determine the Nitrat... more Groundwater flow modelling and mass transport simulation were carried out to determine the Nitrate and Total Dissolved Solid (TDS) migration within the shallow unconfined aquifer of the upper Anga’a river watershed of Yaoundé city, Cameroon. The MODFLOW code calibrated for February 2008 groundwater levels was used to simulate the steady state distribution of hydraulic head. Simulated hydraulic heads were similar to observed values along the watershed in model validation. The nitrate and TDS transport were described by the convection equation and solved using MT3D. The pollutant fate andtransport model (MT3D) reproduced the spatial pattern of observed nitrate concentrations in model calibration and validation. Groundwater and plume velocities were 0.26 and 0.21 m per day respectively. Simulating the contaminant migration from the recharge area shows that the plume may take more than 50 years travel time to reach the central part of the basin from which decision analysis can be made for generating key criteria to secure any water quality from contamination. The application of groundwater modelling tool in this study has shown excellent perspectives for monitoring and protecting aquifer system from spatial and temporal pollutant migration that addresses the concern of changing natural groundwater recharge, population growth and economic development in the study region.
This study attempts to assess the influence of changing land-use patterns on the groundwater qual... more This study attempts to assess the influence of changing land-use patterns on the groundwater quality of the hard rock aquifer system in the Maheshwaram watershed, near Hyderabad, India. The study area is a rapidly urbanizing region with land development progressing at a fast pace. To study the impact of this rapid urbanization and overall land-use transition, a groundwater quality index (GQI) was prepared within a geographical information system (GIS). The GQI integrates the different water quality parameters to give a final index value that can be used for spatio-temporal comparisons. The land-use transitions were closely monitored from 2003 to 2008 using multispectral satellite images. The land-use pattern has changed drastically with an increase in the built-up area at the expense of other land uses. The analysis reveals a rapid deterioration of groundwater quality related mainly to the increase in built-up land with unsewered sanitation and poultry farms. Seasonal variability of the groundwater quality was also assessed. Mean GQI decreased from 84.16 to 83.26 over a period of 5 years from 2003 to 2008, while seasonal variability of water quality increased. GQI and Seasonal Variability of water quality were integrated in GIS to yield a groundwater sustainability map, in terms of water quality. Zones of sustainable and unsustainable groundwater use were demarcated for better decision making related to municipal land allotment in this rapidly urbanizing region.
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