Geomorphological analysis of tropical river basins in southern Kerala using hypsometric indices and neotectonic proxies

Evolutionary geomorphologic stages of tropical river basins of southern Kerala, southwest India were investigated through the state-of-the-art hypsometry analysis and its attributes of 19 river basins (19 RBs). The empirical methodology act as an important tool to understand the relative relief asymmetries with respect to area and enlightens neotectonic controls. Present study on 19 RBs implies that underlying structures control the hypsometric curve (HC). Regression analysis of the basin areas (BA) and hypsometric integrals (HI) showed a positive correlation (R2 = 0.536) for BAs of 500 km2 (n = 4, P = 0.01), the relation becomes weak or negative. Inflection (I) points on the hypsometric curve (HC) of RBs showed least variation implying a slight disparity between the aspect of landform and its evolutionary state. For apprehending the RB evolution, the RBs have been classified into three zones based on major tectonic features. The expedient outcome of this study is the potential and rewarding application in the design and implementation of measures for conserving soil and water in RBs considered. This hypsometric analysis along with neotectonic evidence is together endowed best tool to understand the river basin behaviour and their response to various calamities. Further, it will give an insight to policy makers for future changes on land use.