Analysis of spatial and temporal changes of RUSLE-K soil erodibility factor in semi-arid areas in two different periods by conditional simulation

Abstract

ABSTRACT Soil erosion is the most important soil degradation process threatening semi-arid and arid areas. In this study, the change in the RUSLE-K soil erodibility values due to changed climatic conditions over a 10-year period was used as a tool to investigate soil erosion potential with Sequential Gaussian Simulation (SGS) method in the Mogan catchment in Turkey. For this purpose, soil erodibility values were determined for soil samples taken from the same coordinates in 2000 and 2010, and erosion susceptibility distribution maps were produced. The results showed that even though land use practices remained unchanged, soil erodibility values changed spatially and temporally, with the relationship dependent on climatic factors. More specifically, the effects of decreased precipitation, exacerbated by increased evaporation and more prolonged dry periods, made some areas in the catchment more susceptible to erosion. The vulnerability soils in the catchment increased markedly, with the area classified as subject to ‘very severe erodibility’ increasing more than threefold, from 762 ha to 2477 ha. This study has reinforced the need for ‘minimal disturbance’ land use, supplemented by monitoring that incorporates meteorological and soil test data, to minimize soil erosion and maximize the sustainability of agricultural activities in semi-arid and arid areas.