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, 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 as to drinking and irrigation purposes. The objective of this study is to identify suitable places for groundwater recharge where the process of recharge to the groundwater offers optimum results as per the prevailing hydrogeological conditions. This objective has been achieved by remote sensing and GIS based techniques using DEM and toposheet of the Narain watershed of the Bundelkhand region. In this present study a comparative analysis has been carried out by superimposing drainage network extracted from the toposheet over simulated drainage network derived from the DEM to visualise the clustering tendency of the two data sets. The comparative analysis reveals a mismatch of the two datasets at some places having randomness number less than 1 indicating potential groundwater recharge zones. Such mismatch has appeared at places where the degree of infiltration is significant enough to divert the course of the existing drainage network from the simulated one because of the assumption of the surface to be insulated. This study proves to be a quick reliable method for the identification of groundwater recharge zones for hard rock terrain.