Predicting the spatial patterns of soil erosion hazard using RUSLE and frequency ratio in the Silabati River Basin, eastern India
Ratan Pal, Narayan Jana
Abstract
This research employs the Revised Universal Soil Loss Equation (RUSLE) and Frequency Ratio (FR) models to estimate current soil erosion rates and project future erosion areas in the Silabati River Basin. The average rate of soil erosion was estimated at 4.35 tons/ha/year, significantly below its maximum permissible rate (T) of 12.5 tons/ha/year. However, 12.03% of study area exceeded this threshold. Nineteen soil erosion conditioning factors were taken into account to evaluate soil erosion susceptibility including Rainfall, Elevation, Slope of surface, Aspect of the slope, Topographic curvature, Lithology, Geomorphology, percent of Sand, Silt, Clay and Soil Organic Carbon, Land Use/Land Cover, Vegetation Concentration, Drainage density, Topographic Wetness Index, Terrain Roughness Index, Stream Power Index, and Distance to roads and rivers. High erosion-susceptible locations tend to be found in the upper river basin, where high elevation, steep slopes, high sand and silt content, low clay, and soil organic carbon concentration make it particularly prone to erosion. Moderately vulnerable areas include locales near rivers and lower basin regions with steep slopes and agricultural activities that occupy most of the terrain. The central regions are characterized by dense vegetation that provides erosion protection and are the least vulnerable to erosion. The Receiver Operating Characteristic (ROC) curve was utilized as a validation technique of erosion susceptibility model. The Area Under Curve (AUC) value of 87.40% underscores the model's accuracy in classifying erosion-susceptible zones within the studied area.