Identification of groundwater recharge zones using comparative analysis of drainage networks

Groundwater, being limited extent in hardrock terrain is undeniably a precious resource for livelihood. In the hardrock terrain of Bundelkhand craton, India where seasonal rainfall is mostly discharged through surface runoff, it is necessary to check and delay the surface runoff to mitigate water table decline caused due to overgrowing demand for groundwater. The objective of this study is to identify suitable places for groundwater recharge where the process of recharge to the groundwater offers better results than the vicinity as per the prevailing hydrogeological conditions. This objective has been achieved employing geospatial  techniques using DEM and toposheet of the Betwa Basin of the Bundelkhand craton. In this present study, a comparative analysis has been carried out by superimposing a drainage network extracted from the toposheet over a simulated drainage network derived from the DEMs such as SRTM, ASTER and ALOS PALSAR to visualise the clustering tendency of the two data sets. The comparative analysis reveals a mismatch of the two datasets at some places which are visible on all the DEMs considered indicating potential groundwater recharge zones. Such mismatch has appeared at places where the degree of infiltration is significant enough to alter the course of the existing drainage network recorded on the toposheet from the simulated one because of the assumption of the surface to be insulated. This study proves to be a quick and reliable method for the identification of groundwater recharge zones for hard rock terrains which are regularly experiencing water scarcity.

Keywords: DEM, toposheet, drainage network, hardrock terrain