Multi-criteria-based Morphometric Prioritization for Soil Erosion Susceptibility and Denudation Rate Assessment of Purulia District, India

Abstract

AbstractThe quantitative drainage morphometric analysis is an essential method for understanding the hydrological, geomorphological, geological, and environmental interaction and resultant processes of a particular area or watershed. The present study aims to identify the erosion susceptibility zones and the recent denudational rates by quantitative measurement of morphometric characteristics over the granitic terrain of the Purulia district, West Bengal, India. Erosion susceptibility and denudation rate are measured based on multi-criteria morphometric prioritization and hierarchical anomaly index using remote sensing and GIS techniques. In this study, the ASTER digital elevation data, and Survey of India topographical maps are used to delineate relief, slope, and structure of drainage system such as stream pattern, stream network, stream order, stream length, and others significant linear, relief, and aerial aspects of the sub-watersheds. For the analysis, 27 numbers of sub-watersheds are delineated using digital terrain analysis techniques that cover the entire studied district. Based on the relationship with erodibility, different prioritization ranks are recognized following the estimation of compound values. All the morphometric parameters reveal the interrelations between hydrological processes and their associated geomorphic landforms. Notably, similar drainage pattern and their dominant first-order streams are associated with steep terrain of some sub-watersheds and significantly responsible for more surface erosion. Therefore, high elevated western and southern hilly landscape areas are identified as high erosion susceptibility zone with high-intensity denudation and which also influenced by underlying lithology, associated landforms, and land-use patterns. The rest of the central and northeastern parts of the district have a lesser susceptibility to soil erosion and lower denudation rate which associated with flatted topography with a very gentle slope and hard rock terrain.KeywordsDrainage morphometryRemote sensing and GISSoil erosion susceptibilityHierarchical anomaly indexDenudation