Linkage between Morphological Parameters and Erosion Rate Based on RUSLE for the Prioritization of Sutlej Catchment

Abstract

Quantification of basin characteristics from morphometric analysis helps understand the physical process of erosion. This study performed morphometric analysis and uses the revised universal soil loss equation (RUSLE) on a pixel basis to estimate the space–time variability of soil loss in order to prioritize erosion-prone areas. The morphometric factors considered in the study included linear, areal, and relief aspects of the basin. Average annual soil loss was estimated using the RUSLE model for 21 years (1995–2005) and then used to correlate with morphometric parameters to find out the prioritization criteria for the Sutlej catchment. The Sutlej basin, covering an area of 21,595 km2, is a fifth-order dendritic drainage basin. Its mean bifurcation ratio is 4.06. Based on the values of morphological parameters, prioritization was being done for eight subwatersheds of the Sutlej basin. It was found that the average annual soil loss was strongly correlated with the time of concentration, drainage density, and texture ratio, but not with other morphological characteristics. The study suggested that indices based on morphometric parameters should not be preferred alone for prioritizing catchments prone to erosion. This research works shows the nexus between morphological parameters and their direct relationship with the erosion to prioritize the Sutlej catchment and its subwatersheds. Unlike previous applications, this integrated methodology not only enhances the accuracy of erosion risk evaluation but also addresses the limitations of relying solely on morphometric factors. The results reveal significant correlations between certain morphometric factors and soil loss, emphasizing the need for a multifactorial approach. Additionally, the present study contributes new insights into subwatershed prioritization for targeted erosion control efforts. These innovative findings advance the field by providing a more comprehensive and effective strategy for predicting and managing soil erosion in diverse geographical contexts. Correlation of morphological parameters with erosion rate based on RUSLE can play a significant role to prioritize the watersheds, which is not enough single handedly to demarcate the erosion-prone areas in the catchment for further treatment to conserve the soil loss in the respective region.