Geomorphic indices
for determining neotectonic activity in the Panyor River sub basins, India
Muthamilselvan A., Megaladevi G., Dharani M. and Reji Prasad M.R.
Disaster Advances; Vol. 18(8); 33-47;
doi: https://doi.org/10.25303/188da033047; (2025)
Abstract
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.
