Topographically and hydrologically signatures express subsurface geological structures in an arid region: a modified integrated approach using remote sensing and GIS

This study aims to investigate the ability of remote sensing sensors to map subsurface fault zones with the support of hydrological information collected from boreholes. We first extract linear features crosscut and drain the study area and its adjoining mountainous areas from the Phased Array type L-band Synthetic Aperture Radar (PALSAR), the Landsat 8 images and a set of slope and shaded relief maps derived from the PALSAR DEM using visual interpretation and D8 algorithm. To delineate displacements of subsurface faults were then, interpreted from interpolated maps of groundwater level and aquifer thickness. The subsurface faults are well evident in the form palaeochannels, abruption change in flow direction and the change in the groundwater table and aquifer thickness. The extracted surface linear features were compared against those that exist in the geological map. The result showed that the subsurface geological structures can be indicated from remote sensing and hydrological data.