A Study Of Ground Water Modeling For Shallow Aquifer, In Gandhinagar District, Gujarat

Abstract

Surface water flow and subsurface flow have traditionally been investigated separately and simulators have been developed over the years, to model each of these systems. Growing interest in conjunctive water management, and need for simulations of surface/subsurface flow and their interactions has lead to the linking of models of the respective domains. Groundwater is important and precious freshwater found under the earth's surface. For effective groundwater management, quantitative and qualitative status of groundwater is usually assessed using various groundwater models. However, these models usually suitable for major aquifers and application in minor aquifers are always lag behind due to the requirement of extensive and detailed groundwater data. Since all groundwater bodies are significantly important, GIS functionality was explored in this study to model groundwater using minimal and accessible input data. GIS was used to represent the subsurface geology particularly the aquifer system and to model groundwater flow. The model was used to estimate the groundwater recharge for the Gandhinagar, Gujarat area. This study of Gandhinagar area, using MODFLOW, showed pertaining to the eight layer of the calibrated model. The first layer is a thin soil cover layer of about 3 m uniform thickness. Top layer is kept under unconfined water Table condition, where as the next layers are given the scope of transforming between water Table to confined state and vice versa depending upon the fluctuation of the computed water level with respect to the bottom boundary of the top layer. Other layers are confined or semi-confined having soil type of sand and clay one after another. Model is calibrated with the steady state condition and validated for the transient conditions and groundwater flow condition and recharge analysis is carried out.