Spatiotemporal dynamic of soil erosion in the Roraya River Basin based on RUSLE model and Google Earth Engine

The Roraya River Basin is an important water conservation area in Sulawesi. The soil erosion status in this study was investigated using Revised Universal Soil Loss Equation (RUSLE) on Google Earth Engine (GEE). Soil erosion modulus, a characteristic of the spatiotemporal variation of soil erosion intensity, is calculated and analyzed from various multi-source data. The research results show that (1) the average soil erosion modulus in the Roraya River Basin in 2001–2021 was 307.22 t · h−1 · year−1. This shows that around 25% of the Roraya River Basin requires soil protection measures as the region faces a significant risk of erosion; (2) the trend in the range of soil erosion in the Roraya River Basin in 2001–2021 tends to vary, initially stable, then decreases and increases significantly with increasing altitude and slope (western plateau). A striking trend occurs in various classes of vegetation cover and rainfall erosivity where the increase in soil erosion is caused by both and this applies in reverse, thus encouraging the dynamic development of soil erosion: (3) RUSLE model integrated into GEE can handle vegetation cover factors and conservation measure factors. This is a reliable soil erosion monitoring tool on a wide scale.