Mysore Janardhana

Amol - Ghaemshahr plain in Mazandaran province of Northern Iran hosts a two - tier aquifer system. At places, groundwater has been induced to salinization by seawater intrusion, upconing of palaeoseawater and evapotranspiration processes thus rendering the water unusable. This paper attempts to develop a conceptual model of the hydrological system of the coastal aquifer of the Amol - Ghaemshahr plain. General Modelling System (GMS) was used to integrate log data and to construct a solid model inturn, to generate a 3D model of the hydrostratigraphy of the region. GMS borehole cross sections drawn depict three layer aquifer system- the upper unconfined, middle aquitard and the lower semiconfined aquifers. After calibration, the values of hydraulic conductivity of the upper and the middle impervious layers respectively are 1.9 - 10 m/day and 0.1 m/day, and for the bottom layer 1.9 - 10 m/day. Rivers, lateral inflow and agricultural return flow equally contribute for the recharge of the...

An attempt has been made to evaluate the geotechnical characteristics of volcaniclastic rocks in Taiz city of Republic of Yemen for slope stabilisation of the existing civil structures and new construction purposes. The aim of this paper is to define the quality of volcaniclastic rock mass into several “classes” based on which the concerned civil engineer can take suitable measures for the stabilisation of the rock mass itself.Classifications are made based on field analysis and laboratory measurements. Finally, the indirect method of assessing the quality of the rock mass is also adopted. Rock quality assessment based on two attributes (1) properties of intact rock and (2) joints has been made by determining the Uniaxial Compressive Strength (UCS), Rock Quality Designation (RQD) index and Rock Mass Rating (RMR) system. The volcaniclastic rocks in the study area are represented by tuffs, ignimbrites, breccias and volcanic agglomerates rocks. All these volcanic materials are mainly o...

Lack of data on the hydrogeochemistry of coastal aquifers around the south Caspian Sea warranted the present hydrochemical and quality assessment studies. The study involving classical integrated methods, multivariate statistical analyses, and GIS applications was carried out on the groundwater encountered in coastal Sari–Neka plain, Mazandaran Province, Northern Iran. The present survey indicates that the groundwater encountered at majority (~ 68%) of the sampling locations is of Na+–SO42− category and constitutes deep meteoric percolation type and the same at the remaining ~ 32% of the sampling locations relates to Na+–HCO3− category and belongs to shallow meteoric percolation class. The groundwater situated at ~ 64% and ~ 36% of the sampling locations belongs, respectively, to freshwater and brackish water categories. The groundwater is specified by Na+ > Ca2+ > Mg2+ > K+ and HCO3− > Cl− > SO42− > NO3−. It pertains to Ca2+-Mg2+-HCO3−, mixed, and Na+-Cl− hydrochemical facies. Reverse cation–anion-exchange process was found dominant at majority (~ 76%) of the sampling sites. Dissolved solids were originated chiefly from connate brine water confined to the aquifer sedimentary beds, dissolution of aquifer materials, ion-exchange, and different anthropogenic sources. Groundwater encountered at ~ 71% and ~ 27% of the bore well locations belongs to good and excellent categories of drinking water, while that at ~ 73% of the sampling locations pertains to (C3S1) irrigation water class of Richards (Diagnosis and improvement of saline and alkali soils (USDA. Agriculture handbook, Vol. 60). U.S. Department of Agriculture, Washington DC, 1954). The results of the present study are useful for planning sustainable management and protection of the groundwater in coastal areas, especially around the Caspian Sea, and serve as a database for international researchers.

Engineering properties of the rocks play an important role for designing urban infrastructures in natural hazard prone areas. The entire Taiz city in Yemen is built on volcanic flows and their variants. This paper presents the first report on the description and the engineering characteristics of the Tertiary basaltic lava rock masses in and around Taiz city, Yemen. Geoengineering assessment was made by well established direct and indirect approaches. The direct approach involved the evaluation of physical and mechanical characteristics as well as discontinuity measurements of 23 representative outcrops and field tests. The indirect approach is comprised of characterization of rock masses using Rock Mass Rating (RMR) system and determination of Geological Strength Index (GSI), shear strength parameters (c, φ), compressive strength (σcm), tensile strength (σtm) and deformation modulus (Erm) of the jointed basaltic lava flow rock masses using the generalized Hoek–Brown criterion emplo...

Gravity and magnetic surveys were conducted in an area about 5000 km² covering offshore region of the Qamar basin in the eastern part of Yemen. An attempt is made to address the gravity and magnetic signatures in term of structural features. In addition, seismic section (NIM-QAM-92-201) compiled by Nimir services limited, 1992 were used to illustrate subsurface structures in sedimentary sequences. Combined gravity and magnetic modeling along section QAM-92-201 by Geomodel 2.5D inversion technique suggest the thickness of sediment to vary from 3.2 to 5.3 km in the Qamar basin (offshore), and the basement rocks are divided into blocks because of existence of several faults extending from basement rocks to sedimentary rocks owing to strong tectonic activities. So the study area may be divided into several major blocks along the Qamar Gulf. It can be concluded that the sedimentary processes were affected by basement tectonics as revealed by the seismic section.

Groundwater is a natural resource for drinking water. Assessment of ground water quality status in Mysore city by using water quality index (WQI) method was carried out. From the sampling locations spread throughout city, 53 groundwater samples were collected both in pre-and post-monsoon seasons. WQI has been determined by subjecting the samples to comprehensive physicochemical analysis. For calculating the WQI, the following 13 parameters have been considered: pH, EC, TH, TDS, Ca 2+ , Mg 2+ , Na + , K + , CO 3 2-, HCO 3 -, SO 4 2-, Cl -and NO 3 -. The WQI for the groundwater samples ranges from 42.61 to 109.51 and from 39.82 to 166.19 for PRM and POM seasons respectively. The results of some of the water samples show values over the permissible limits of WHO and BIS standards for drinking waters for parameters such as calcium and magnesium cations, nitrate and sulphate anions, and also in the global parameters: salinity and TDS. The elevated value of WQI has been found to be mainly...

The Qamar basin is an onshore/offshore basin in Yemen comprising post-Palaeozoic sedimentary formations resting unconformably on Precambrian basement. An attempt to bring out structural features of the basin is made based on the data compiled by marine gravity survey. The Bouguer anomaly data has been separated and regional and residual anomaly maps have been produced by applying Finite Element Method (FEM). The study suggests a series of faults with a graben at the central part of the basin.

ABSTRACT Amol-Ghaemshahr plain, Mazandaran province, Iran, is bestowed with a large two-tier aquifer system (area: 1100 sq.km) confined to detrital sediments of Quaternary age. Upper unconfined aquifer is located in 10 to 60 m (av. 25 m) thick detrital sediments. The unconfined aquifer is underlain by a detrital sedimentary impervious layer varying from 4 m to 62 m (av. 19 m). Confined aquifer located below the impervious sedimentary layer is found in 50 to 200 m (av.150 m) thick detrital sediments. It is underlain by sand and silt horizon with salt water(brine). Groundwater from 40 shallow and 33 deep bore wells drilled, respectively in the confined and unconfined aquifers reveal the presence of two hydrochemically differing facies. In comparison with the groundwater of the unconfined aquifer, the groundwater from the confined aquifer contains, on average, lower concentrations of Ca2+, Mg2+, K+, HCO3, SO4 -, NO3 - and total ions and higher concentrations of Na+ and Cl-. Groundwater from the confined aquifer consists of Ca-HCO3, Na-Cl, Na-HCO3 and Ca-Cl type waters, whereas the same from the unconfined aquifer is made up of Ca-HCO3, Ca-Cl and Na-HCO3 type waters. Presence of Na-Cl type groundwater in the confined aquifer is mainly due to intrusion (upconing) of saline water from the saltwater-bearing sandy clay horizon underlying the confined aquifer as a result of over pumping. Groundwater from 9 bore wells from the confined aquifer and 7 bore wells from the unconfined aquifer is unfit for drinking purposes owing to the presence of one or more among 4 parameters (viz., EC, TH, Na+ and HCO3 -) in excess of the maximum permissible limits. On the bivariate SAR versus EC diagram, groundwater from 40 bore wells from the unconfined aquifer plot in the Richards' C3S1 (n=39) and C4S1 (n=1) water classes. Groundwater from 33 bore wells from the confined aquifer belongs to Richards' C2S1 (n=7), C3S1 (n=20), C3S2 (n=4) and C4S2 (n=2) water classes. Quality-wise, the groundwater from the unconfined aquifer belongs practically to "marginally good" water class, whereas the same from the confined aquifer consists of "good", " marginally good", "bad" and "very bad" water classes. Keywords: Two-tier aquifer, Groundwater, Hydrochemical facies, Water quality, Amol-Ghaemshahr plain, Northern Iran.