MODFLOW Based Groundwater Budgeting Using GIS: A Case Study from Tirunelveli Taluk, Tirunelveli District, Tamil Nadu, India

Extensive use of freshwater resources for day-to-day human consumption will cause alarming situations in environmental water balancing. Groundwater is considered as the primary source for living organism due to limited availability of surface water systems in arid and semi arid regions. An attempt is made in this study, to develop numerical simulation of groundwater flow and quantification of groundwater availability in Tirunelveli taluk using Remote Sensing and GIS techniques. The study area lies between eastern longitudes of 77°32′16″ and 77°48′8″ and northern latitudes of 8°40′12″ and 8°56′34″ with a spatial extent of 558.4 sqkm. The initial input parameters of MODFLOW such as boundary conditions and layer properties are prepared from data issued by Public Works Department. The data consists of groundwater level, aquifer property and lithology. Topographic map was received from Survey of India. SRTM DEM was downloaded from USGS web archives and resampled the above data using ArcGIS environment. ModelMuse package of USGS was used to develop the quantitative three dimensional steady and transient state flow model of groundwater system, based on the available hydrological field data. The calibration process of ModelMuse simulated groundwater flow result was carried out using, field based well water level data collected for the study period using ModelMate package. The simulated results have shown the over extraction activity of groundwater resource (103.696 m3) is performed in the study area. This study also demonstrates that integration of Remote Sensing, GIS, traditional fieldwork and mathematical models is a powerful tool in understanding the demand and supply of groundwater.