Hypsometric Analysis of Terrain Evolution and Erosional Stages of the Thamirabarani River Basin Using GIS and Remote Sensing

Abstract

Hypsometric analysis provides an effective quantitative approach for understanding geomorphic evolution and erosion dynamics of river basins. The present study evaluates the terrain characteristics and erosional stages of the Thamirabarani River Basin, Tamil Nadu, India, using Remote Sensing (RS) and Geographic Information System (GIS) techniques. A 30 m resolution Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) was utilized to delineate the watershed and its sub-basins, extract drainage networks, and derive elevation parameters. Hypsometric curves were generated based on the relationship between relative area and relative elevation, while the hypsometric integral (HI) was computed using standard empirical methods. The results indicate that the Thamirabarani River Basin exhibits an HI value of 0.47, corresponding to a mature stage of geomorphic development. The S-shaped hypsometric curve further confirms a balanced state between erosion and deposition processes, suggesting moderate landscape dissection and progressive stabilization. Spatial analysis reveals that higher elevations in the Western Ghats are less affected by erosion, whereas low-lying regions are more vulnerable due to increased runoff and anthropogenic influences. The study highlights the significant role of geological structure, climatic conditions, and human activities in controlling erosion processes and terrain evolution. The findings emphasize the need for targeted watershed management strategies, including soil and water conservation measures, to mitigate erosion and enhance sustainability. The integration of GIS-based analysis with hypsometric techniques provides a robust framework for assessing watershed conditions and can be applied to similar river basins for effective environmental planning and management.