Identifying areas of differential uplift using steepness index in the Alaknanda basin, Garhwal Himalaya, Uttarakhand

摘要

In this paper an attempt has been made to identify places of high surface uplift in the Alaknanda valley using the steepness index method. Locations that are undergoing faster surface uplift are marked by convex river profile and high steepness index(ks) values. Conventionally, the Main Central Thrust (MCT) is known to be the zone of high uplift (incision), which accords well with our analyses. The second zone of relatively higher surface uplift is identified south of the MCT around Chamoli, Nandprayag and Karnprayag. These locations are traversed by the Chamoli, Nandprayag and the Alaknanda faults respectively. Our preliminary study suggests that for future earthquake risk evaluation, detailed geomorphological and seismotectonic studies should beundertaken in this area.