Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

M. Thangarajan ¹, V. S. Singh ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

With the growing needs of water, particularly in developing countries, groundwater resources are being exploited indiscriminately. Evolution of pumping schemes for the development of groundwater resources has become an imperative need to minimise the environmental hazards. This, in turn, requires a reliable estimation of hydrogeological parameters and quantitative appraisal of interference between wells. Pumping tests using a distributed battery of wells may give a representative estimate of aquifer parameters valid over a large area.

One such study was carried out in the Neyveli basin, Tamil Nadu (India), using pumping test data on wells distributed over a total distance of about 2 km. The spread of observation wells was about 4 km. The pumping was continued till a steady state condition was achieved which was monitored through continuous recording of water levels in the observation wells. The drawdowns at any observation point due to pumping of a number of wells is calculated using the principle of superposition. Forward modelling has been employed for the estimation of aquifer parameters through comparison of computed and observed drawdowns. This approach, besides enabling estimation of hydrogeological parameters, can also provide a first-order basis to design an optimal spatial pattern of wells and pumping rate to achieve a specified drawdown in a certain area.

Keywords

Hydrogeology, Aquifer Parameters, Neyveli Basin, Tamil Nadu.

Full Text

     

M. Thangarajan ¹, V. S. Singh ¹, M. Sriman Narayan ²

Affiliations
1 National Geophysical Research Institute, Hyderabad-500 007, IN
2 Public Works Department, Government of Tamil Nadu, Chennai - 600 005, IN

Abstract

Hydrodynamics of groundwater flow regime in a hard rock region and its quantification are not yet fully understood. This is mainly due to several uncertainties involved in quantifying the hydrogeological parameters, Numerical techniques are found to be potential tools in interpreting hydrogeological parameters in hard rock regions as well as studying the aquifer response for given input/output stresses.

One such study was carried out in Palar river basin, Tamil Nadu, where pumping tests carried out on large diameter wells were interpreted using a numerical technique. The aquifer parameters (transmissivity - T and storage coefficient - S) evolved through pumping tests were then used to characterize the groundwater flow regime.

Keywords

Groundwater, Hard Rock Terrain, Hydrodynamics, Palar Basin, Tamil Nadu.

Full Text

     

P. N. Ballukraya ¹, V. S. Singh ²

Affiliations
1 Department of Applied Geology, University of Madras, Chennai, IN
2 NGRI, Hyderabad, IN

Abstract

No Abstract.

Full Text

   

R. K. Prasad ¹, N. C. Mondal ¹, V. S. Singh ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad-500007, IN

Abstract

Groundwater resources potential has been evaluated in Kurmapalli watershed, Andhra Pradesh, India using Geographic Information System (GIS) technique. It allows manipulation and analysis of individual layer of spatial data. It is used for analyzing and modeling the interrelationship between the layers. Various thematic maps have been prepared for geology, geomorphology, slope, drainage-density and lineaments of the study area using GIS technique. These thematic maps have been integrated with the help of GIS. Appropriate weightage has been assigned to various factors controlling occurrence of groundwater to assess the total groundwater potential in each segment of the study area. The results show that there are five categories of groundwater potential ranging from very good to poor. The categorizations of groundwater potential zones are in general agreement with the available yield data of the 438 existing dug wells, bore wells and tube wells. This depicts the favourable prospective zones in the study area for evaluation of groundwater potential.

Keywords

Hard Rock Aquifer, Aquifer Yield, Evaluation of Groundwater Potential, GIS, Spatial Analyst Tool.

Full Text

     

D. V. Sarwade ¹, V. S. Singh ¹, S. C. Puranik ², N. C. Mondal ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN
2 Kamatak University, Dharwad - 580 003, IN

Abstract

Estimation of aquifer parameters namely transmissivity (T) and storativity (S) are vital for the evaluation of groundwater resources. To estimate the accurate aquifer parameters, there are several methods (i e hydrograph analysis pumping test, etc). In Asian and Southeast Asian countries large diameter wells are abundant and they are often cost effective means to conduct pumping test as one can use the farmer's pump to perform this test. There are several suggested methods to estimate aquifer parameters through pumping test data, in which, curve matching and numerical methods are widely used. In this paper we have given special emphasis to pumping tests and data interpretation, which were carried out at 12 locations in a basaltic terrain at Belgaum city, Kamataka, India. The data is interpreted by using both analytical and numerical methods, and compared with them The results of analytical methods have shown up to 35% error involved in the calculated drawdown as well as residual drawdown in comparison with the field observations, whereas it is less than 45% m the case of numerical method Hence the present study shows that the numerical method IS found to be more accurate than the analytical curve matching method for estimating the aquifer parameters.

Keywords

Hydrogeotogy, Unconfined Aquifers Pumping Test, Analytical And Numencal Methods Transmissivity, Storage Coefficient, Belgaum City, Kamataka.

Full Text

     

V. S. Singh ¹, M. Thangarajan ¹

Affiliations
1 National Geophysical Research Institute, Uppal Road, Hyderabad - 500 007, IN

Abstract

Kodaganar river basin is a hard rock terrain where the upper shallow weathered part followed by deep fractured rocks form the aquifer system The area is drought prone and indiscriminate exploitation of groundwater over decades has resulted in depletion of water level Therefore, assessment of groundwater potentia1 is warranted which in turn requires the knowledge of aquifer parameters The common practice of determining the aquifer parameters is by carrying out pumping test on wells and further by interpreting the time drawdown data In the present study the aquifer parameters are determined through pumping tests on dug wells duly taking into account the actual field conditions while interpreting the data Numerical method has been adopted to carry out forward modelling of pumping test data to estimate aquifer parameters.

Keywords

Hard Rock Terrain, Aquifer Characteristics, Numerical Method, Kodagana River Basin, Tamil Nadu.

Full Text

     

V. S. Singh ¹, S. C. Jain ¹, T. V. Rao ¹, M. N. Rao ¹, B. C. Negi ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

Shales/limestone, which are devoid of primary porosity, often act as the potential aquifers when they are fractured and/or weathered. An integrated approach employing photogeologicil, hydrogeological and geophysical investigations has now been attempted to delineate groundwater potential zones in such shaley limestone terrain at the southern part of Chandrapur District of Maharashtra. This cost-effective approach, which was focussed at sites delineated from aerial photo interpretation has helped in drilling of good yielding wells in an otherwise unpromising shaley limestone terrain.

Full Text

   

V. S. Singh ¹, M. Thangarajan ¹

Affiliations
1 National Geophysical Research Institute, Uppal Road, Hyderabad, 500 007, IN

Abstract

Aquifer parameters viz. transmissivity (T) and storage coefficient (S) are a pre-requisite for the assessment of groundwater resources in an area. A large number of dugwells tapping the top phreatic aquifer (comprising mostly weathered material) are being utilized for irrigation and/or domestic purposes. Use of such wells makes the estimation of aquifer parameters easy and cost effective. A case study in Vaippar river basin, a hard rock region in Tamil Nadu (India) is presented.

Keywords

Hydrogeology, Aquifer Parameters, Pumping Test, Large Diameter Wells, Recovery Data, Tamil Nadu.

Full Text

     

V. S. Singh ¹, M. Thangarajan ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

In many situations pumping tests are carried out without observation well and drawdown/recovery, data recorded in the pumped well itself. Although, the time drawdown/recovery data are, being precisely recorded in the pumping well, the interpretation of such data often gives ambiguous results due to non-accountabiiity of well loss and well storage in many situations. This is particularly true in the case of low permeable aquifer. In order to overcome such difficulties, finite difference, method is used to estimate aquifer parameters. Field examples are presented to illustrate the above method.

Keywords

Hydrogeology, Aquifer Parameters, Pumping Test, Well Storage, Well Loss.

Full Text