Envisaging the Sustainability of an Aquifer by Developing Groundwater Flow Model for a Part of ChoutuppalMandal, Nalgonda District, Telangana, India

Abstract

Recurring droughts and increased exploitation of groundwater to meet the growing water needs have resulted in the decline of regional groundwater level and drying weathered zone in a part of the Choutuppal Mandal, Nalgonda district, Telangana, India. In this study, a preliminary steady state groundwater flow modelling has been carried out by using Visual MODFLOW Classic Interface (Build 4.6.0.168), well inventory data from the existing 20 observation wells and a base map for the subsurface structure in order to evolve the future pumping schemes. The area spreading about 0.43 km2 is conceptualized as a two-layered model consisting of a weathered layer overlying a fractured aquifer. The model has been digitized into grids of 5m×5m in each layer. The integrated finite difference method has been utilized to discretize the groundwater flow equation and simulate groundwater flow with the help of calculated parameters along with the boundary conditions and acting stresses. Results show that the computed groundwater levels are in good agreement with the observed heads, and groundwater is flowing from the South to the North direction. The estimated velocities vary from 0.01 to 1.95 m/d. The optimum pumping schemes have also been simulated up to the year 2022. It has been observed that the maximum pumping rate should not go beyond 24 m3/day. Since the drinking water demand (10-15 m3/day) in the study site is below this limit, it can be inferred that the aquifer will sustain and provide enough drinking water.