Appraisal of Soil Conservation Capacity Using NDVI Model-Based C Factor of RUSLE Model for a Semi Arid Ungauged Watershed: a Case Study

Abstract

Revised Universal Soil Loss Equation (RUSLE) model and Geographic Information System (GIS) have been used to map and quantify vulnerability of soil erosion in a semi arid ungauged Jhagrabaria watershed of Allahabad district of state Uttar Pradesh, India. The spatial pattern of average annual soil erosion rate was estimated by integrating different thematic layers at GIS platform. GIS vector layers including, rainfall erosivity (Ro), slope length and steepness (LS) factor, soil erodibility (K), conservation practices (P), and cover management factor (C) have been estimated using satellite data and Normalized Difference Vegetation Index (NDVI), respectively. The resultant map of average annual soil erosion shows a maximum soil loss in range of 0.3 to 0.6 t ha−1 year−1 (82.41 km2 and 54.92% of watershed area). While maximum soil loss ranges from > 9.0 t ha−1 year−1 (0.67 km2 and 0.45% of watershed) was reported under hillocks (lower part) of the study area. The work outlines that the vegetation cover arrests the soil erosion in the region. The study provides spatial erosion risk maps of 30 m. These maps will be useful in developing better strategies for land planning and management in the environmentally sensitive small hillocks areas.