Geoinformatics based detection and delineation of paleochannels in hard rock terrain of Koel River Basin, Jharkhand, eastern India

Paleochannels evoke interest in view of their geological/tectonic history, the origin of their sediments composition, and prospecting for groundwater resources. The present study demonstrates the delineation of paleochannels in hard rocky terrain in parts of the Koel river basin in the Jharkhand state in eastern India. High-resolution optical satellite data Sentinel-2 and Synthetic Aperture Radar (SAR) data from Sentinel-1 have been used to carry out the visual interpretation for the identification of paleochannels in the prospects of groundwater resources. Six major paleochannels locations were identified based on flow direction, flow accumulation, drainage, closed depression area, normalized difference water index (NDWI) (pre and post-monsoon seasons), and Topographic Wetted Index (TWI). The abandoned courses were recognizable as curvilinear or meandering segments of dry channels by using the drainage map. Pre and post-monsoon NDWI exhibited water storage zones, which were generally filled after monsoon season by rainwater along the paleochannels. TWI more than 1.3 and depression more than 30 depicted wetted zones along with the delineated paleochannels locations. Both the satellite-derived (NDWI) and digital elevation model (DEM) derived (i.e. TWI, depression area, drainage) indices indicated the presence of six major paleochannels, which were further corroborated with radar data and field-based data. Areas of low topography with dendritic drainage, depth and flow direction was studied which controls the recharge potential of groundwater and pattern were investigated where the chances of occurrence of groundwater are more. This comprehensive study concluded that satellite-based information can be useful for demarcating paleochannels over hard rocky terrains and TWI performed better compared to other parameters (NDWI, drainage, and morphometric study) as an indication of potential groundwater prospects. [Display omitted] •Sentenal-2 and Synthetic Aperture Radar (SAR) data have been used to carry out visual interpretation for identification of paleochannels.•Satellite based indicator and hydrological parameters were used to identify major paleochannel locations.•The study revealed the usefulness of geoinformatics for paleochannels delineation in hard rock terrain.•This unique study could be beneficial for the extraction of ground water recharge zones by demarcating paleochannels in hard rock terrain.