Geospatial Analysis Of Denudational Processes In Auranga River Basin

Abstract

Denudation is a geomorphic process involving the breakdown, erosion, transportation, and eventual deposition of rock and soil materials from higher to lower elevations. The present study investigates the spatial patterns and intensity of denudational processes in the Auranga River Basin, located across parts of Gujarat and Maharashtra, using topographic maps and satellite-based Digital Elevation Models (DEMs) from 1966–67 and 2018. The analysis was conducted through GIS-based spatial modeling, particularly the cut-and-fill tool, to quantify surface changes over time. The Auranga basin, covering approximately 800 km², reveals significant erosion (1596.64 km²) and deposition (711.95 km²), with only 0.0016 km² remaining unchanged. Sub-basin level assessment indicates the highest erosion in the Tan and Man river sub-basins (319.52 km² and 313.06 km² respectively), followed by varying degrees of material removal and deposition in Nirpan, Lower Tan, Vanki Nadi, and Lower Auranga sub-basins. These changes correspond with physiographic features such as dissected hills, slopes, and riverbanks. The results emphasize the dynamic geomorphological transformation of the basin, driven by natural agents including weathering, mass wasting, erosion, and fluvial transportation. This spatial evaluation aids in understanding landscape evolution, watershed management, and planning for sustainable land use in the Auranga river basin.