Neotectonic Control on Drainage System in Gangetic Plain, Uttar Pradesh

Study of remotely sensed data and SOl topographical maps with some field observations has helped in the identification of lineaments controlling the drainages, using various indications like displacement of Siwalik hills, skewness of fan surfaces, preferential alignment of river channel, knick points, distorted meanders, abrupt change in river courses, escarpments and asymmetrical terraces. The northern part of the Gangetic plain, the Piedmont zone shows two major lineaments, i.e. NNE-SSW and NW-SE, developed as conjugate strike slip features, with some evidences of gravity component. The NW-SE direction of the conjugate system is very prominent in Central Alluvial Plain and has controlled the major drainages. These lineaments have caused abrupt change in flow directions of many streams; and in parts, have behaved as gravity fault with NE blocks as downthrown side. The drainage in the Marginal Alluvial Plain (southern part) is essentially controlled by the reactivated basement lineaments of predominantly SW-NE direction. The drainage of northern and central part of Gangetic plain is controlled by newly developed lineaments formed due to compressional stresses of the Himalaya while drainage in southern part is controlled by reactivated basement lineaments.