Sub-watershed Prioritization for Soil Erosion Potentiality Estimation Based on Integrated Approach of Morphometric Analysis, Hypsometric Analysis and R- Factor: A Study of Pagladiya River Basin

Abstract

Abstract

Prioritisation of sub-watersheds for the purpose of soil erosion estimation within the Pagladiya watershed has been carried out through three significant approaches—morphometric analysis, hypsometric analysis, and the R factor (RUSLE model). Significantly, the watershed is segmented into 6 small sections of sub-watersheds (Sb-W1 to Sb-W6) using hydrology tools in ArcGIS. In the morphometric analysis approach, 14 variables are considered to assign priority rankings based on compound values, where Sb-W1, Sb-W2, and Sb-W3 are identified as high-priority sub-watersheds. An inter-correlation matrix is also used to gain a detailed understanding of how the morphometric variables are related to each other and how these relationships influence soil erosion. For the R factor (RUSLE model), CRU 2024 rainfall data is utilised to estimate soil erosion due to rainfall. This analysis reveals high priority in Sb-W1 and Sb-W3. Sb-W1, Sb-W4, and Sb-W5 are categorised as high priority based on hypsometric integral. Again, by integrating all three approaches, Sb-W1 is found as a common high-priority area. Significantly, Sb-W1 followed by Sb-W3 (total area 580.65 km²) requires urgent soil conservation measures, while the remaining sub-watersheds should be regularly monitored to prevent future soil erosion.