Morpho-tectonic Analysis of an Upstream Sub-basin of the Cauvery River from Bhagamandala to Shivanasamudra using Geomorphic Indices using GIS

The Cauvery sub-basin, with an elevation of 2029 meters, is a mountain range that has been uplifted during the Cretaceous period and is bordered by the Western Ghats. The two northern mountain fronts and the southern front of the Cauvery sub-basin are defined by faults near the origin point (catchment area). We conducted a morpho-tectonic analysis by assessing the properties of geomorphic indices to uncover variations in rock uplift. In particular, the study contrasts the northern and southern mountain fronts' valley height to floor ratio, area-height correlations (hypsometric curve), and mountain front sinuosity (Smf). The high land in the sub-basin and key faults in the northern part of the Western Ghats (with an average height of approximately 2029 meters), indicate the uplift of both geomorphic units as part of a single extensive crustal block. The asymmetry factor indicates that there are imbalances in the Cauvery River, with an increased slope toward the sub-basin's left side. Transverse topographic symmetry also suggests that the sub-basin experiences tectonic activity at both the source and endpoint, where Shivanasamudra falls is located. Likewise, other morpho-tectonic indices reinforce the observation that both the starting and ending points are tectonically active. Finally, river profiles reveal that the sub-basin's left section displays the most notable river entrenchment, likely due to uplift. Our geomorphic assessment indicates that the Western Ghats within the Cauvery sub-basin region exhibit tectonic activity, characterized by a series of faults along the mountain's leading edge. The presence of Pseudotachylites connected to the fault system indicates that neo-tectonic processes also have an impact on the Shivanasamudra falls, which are situated at the end of the research region.