Evaluation of groundwater prolific zones in the unconfined basaltic aquifers of Western India using geospatial modeling and MIF technique

A study on sub-watershed scale covering an area of 593 sq km representing basaltic terrain was performed with the aim of finding the areas with groundwater potential using geospatial modeling and multi-influential (MIF) method. Various thematic layers of influential parameters were generated with GIS-based modeling approach. ASTER-GDEM image having 30-m pixel resolution was acquired to construct the digital elevation model (DEM); further, the drainage network and slopes were generated using DEM. The published district resource map of geology was referred to prepare the geology and geomorphology layers. Totally, 57 dug wells were inventoried and groundwater level fluctuation map was created using pre- and post-monsoon water levels. The ranks were allotted to specific factor of each influential layer, and weights were given to subclass, based on the degree of influence using MIF. Superimposition of all the thematic layers in ArcGIS was carried out to obtain the potential zonation map. Further, it has been observed that the excellent to very good category covers 29.11%, very good to good 20.96%, good to moderate 22.31%, moderate to moderately poor 23.07% and moderately poor to poor 4.55% of the total area. The resultant zonation map was validated with groundwater level fluctuation values, and it clearly showed that the high-yielding dug wells were located in the high potential zones. Thus, the evaluation of groundwater prolific zones would play a key role in sustainable development and judicial planning of this resource in the study area.