Geomorphic indices for determining neotectonic activity in the Panyor River sub basins, India

In the present study, an attempt has been made to assess the neotectonic activity within the 20 sub-basins of the Panyor river using geomorphic indices. The geomorphic indices like asymmetry factor, transverse topographic symmetry factor, hypsometric integral, stream-length gradient index, drainage basin shape index, ratio of valley floor to valley height and mountain front sinuosity were estimated and the values range from 36.61 to 63.82, 0.12 to 0.54, 0.46 to 0.50, 0.68 to 3.89, -0.29 to 1.76, 75.27 to 1198.93 and 1.42 to 5.81, respectively. Further, the index of relative active tectonics (IRAT) was derived from the geomorphic indices and it ranges from 1.17 to 2.29. Based on the IRAT values, the Panyor sub-basins were grouped into three classes based on the neotectonic activity viz. very high (1.0-1.5), high (1.5-2.0) and moderate (2.0-2.5). The IRAT classes determined indicate that the neotectonic activity has a strong control in subbasin 5 and it spatially increases from the southwestern part of the basin to the northeast.