Soil erosion vulnerability assessment in the eco-sensitive Himalayan region using modeling approach

Abstract

Soil loss due to erosion has a huge impact on worldwide economy and environment. Himalayan region is extremely vulnerable to erosion due to rugged terrain, erratic precipitation and excessive anthropogenic pressures. This study attempts to assess the spatial distribution of soil loss for managing soil disintegration rates in the western Himalayas using GIS modeling approach. Factors affecting soil erosion were assessed and mapped using primary data from the field and secondary data. Map layers were developed for each identified factors and modeled using weighted overlay analysis. The rainfall-runoff erosivity, soil erodibility, topographic, cover management and support parameters varied around 361.75 MJ mm/ha/h/yr, (0.024 - 0.051) t ha h/ha/MJ/mm, 0 to 585.372, 0 to 1 and 0 to 1 respectively. The yearly soil disintegration rate varied between 0 and 6098.44 t ha/yr. The maximum area (137165.30 ha) of the district’s total area (146295.142 ha) was under the less vulnerable class and the minimum (259.92 ha) was under the severely vulnerable category. The findings reported 70.24% of the area was under the less vulnerable class, followed by extremely vulnerable (10.48%) > highly vulnerable (7.40%) > severely vulnerable (7.19%) > moderately vulnerable (4.69%). The maximum (810 t/ha) and minimum (15 t/ha) mean soil loss was found under severely vulnerable and less vulnerable categories. The findings will provide site specific data regarding soil loss and vulnerability for effective management of soils in the eco-sensitive region.