Soil erosion assessment using revised universal soil loss equation model and geo-spatial technology: A case study of upper Tuirial river basin, Mizoram, India

Abstract

Soil erosion is one of the major environmental problems in northeast India, and identifying areas prone to severe erosion loss is therefore very crucial for sustainable management of different land uses. Tuirial river basin, where shifting cultivation is a major land use, is prone to severe soil erosion and land degradation, linked to its fragile geo-morpho-pedological characteristics. Though several models are available to estimate soil erosion the Revised Universal Soil Loss Equation (RUSLE) is more appropriate and practical model that can be applied at a local or regional level. The objective of the study was to estimate annual soil loss in the upper Tuirial river basin by using RUSLE where various parameters such as rainfall erosivity factor (R), soil erodibility factor (K), slope length (L), slope steepness factor (S), crop management factor (C) and practice management factor (P) were taken into consideration. Land use land cover (LULC) derived from Satellite data of Sentinel 2A Digital Elevation Model (DEM) were integrated into the model. Our results revealed that the river basin has an average annual soil loss of 115.4 Mg ha−1 yr−1, and annual sediments loss to the tune of 6.161 million Mg yr−1 from the basin. About one-fourth (24.78%) of the total basin could be classed as very high to very severe soil erosion prone area that need immediate conservation measures. Besides, the erosional activities were perceived directly proportional with the slope values in the basin. However, regardless of the rugged mountainous terrain of the basin, the unscientific practice of shifting cultivation, associated with high intensity of rainfall is the principal cause of soil erosion. The results of the study is expected to contribute to adaptation of appropriate soil and water conservation measures in the basin area, and similar studies may also be extended to other unexplored areas for proper watershed management in state of Mizoram.