Structural and Lineament Mapping on Satellite Images for Deciphering Hydrogeologic Situation in Banas River Basin, Rajasthan, India

Structural and Lineaments in Banas river basin of eastern Rajasthan are mapped and classified into various categories using satellite images. In all,174 lineaments are recognized (including those, which are closely distributed or parallel, numbered as group of lineaments) belonging to various categories as curvilinear structural ridges, topographic escarpments, straight active river segments, straight dry channels, previously mapped major lineaments and previously mapped major faults. Some of the regional lineaments e.g. major faults are represented by combination of few of these categories. It has been found that in general, there is a appreciable correlation of the lineaments with major lithologic contacts, major faults and major stream courses. The lineaments of hydrogeologic significance are termed as hydrogeofractures e.g. Great Boundary Fault, as either they are occupied by the straight channels or water bodies within their intersection zones, The lineament intersection density map prepared for 20Km X 20Km grid presents 9-level density zones, which indicate the aquifer situation improving with successive increase in density level. The maximum occurrence of lineaments E-W direction reflects the response of tectonic reactivation in the Quaternary period. The lineaments besides having their hydrologic importance are also seismically significant