Estimation of Aquifer Parameter in Basaltic Region through Aquifer Performance Test: A Case Study of Laxmi and Sheri Nala Basin (KR 40 watershed) Around Sangli, Maharashtra (India)

摘要

The estimating the aquifer parameters is an essential part of the groundwater studies to understand the origin and movement of groundwater which are the fundamental questions that addresses both the temporal and spatial aspects of ground water and water supply related issues in arid and semi arid climatic regions. As the study area i.e. Laxmi and Sheri nala basin (KR 40 Watershed) falls in semi arid region where water scarcity is the main problem, ultimately the groundwater is the major source. Thus the estimation of aquifer parameters is essential task is needed to carried out in the study area. There are several methods to estimate the accurate aquifer parameters (i.e. hydrograph analysis, Aquifer performance test etc.). In early days, these parameters are estimated either by means of in situ test or performing test on aquifer samples brought in the laboratory. The most common in-situ test is Aquifer performance test (APT) performed on wells, which involves the measurement of the fall and increase of groundwater level with respect to time. The alteration in groundwater level is caused due to pumping of water from the well i.e. drawdown and recovery. Theis (1935) was first to propose method to evaluate aquifer parameters from the pumping test on a bore well in a confined aquifer. It is essential to know the Specific capacity (C), transmissivity (T), storativity (S) and Specific yield (Sy) for the characterization of the aquifer parameters in an unknown area so as to predict the rate of drawdown of the groundwater table surface throughout the pumping test of an aquifer. The determination of aquifer's parameters is an important basis for groundwater resources evaluation, numerical simulation, development and protection as well as scientific management. Hence in the study area total nine aquifer performance tests (APT) has been carried out and accordingly the study area divided into high, moderate and lower groundwater potential zones.