Simulation of Soil Erosion on the Yunnan–Guizhou Plateau Under Future Climate Scenarios Based on the SSPs-RUSLE Coupled Model

Soil erosion on the Yunnan–Guizhou Plateau (YGP) has a significant impact on the water sources and ecological safety of Southeast Asia and South China. With the influence of climate change, this erosion has been altered, which will create uncertainty regarding soil erosion management and social development in China and Southeast Asia. However, existing research still lacks simulations of soil erosion in large-scale regions, as well as a systematic understanding of the spatiotemporal characteristics of future soil erosion under climate change. Therefore, a coupled model of the Shared Socioeconomic Pathways (SSPs) and the Revised Universal Soil Loss Equation (RUSLE) at the regional scale of the YGP is proposed in this study. By analyzing the erosion patterns in the YGP, this research determines the optimal future scenario and corresponding mitigation strategies, thereby offering a localized practical reference for soil erosion control in the YGP and its alignment with the UN SDGs. The results show the following: (i) Temporally, soil erosion on the YGP will improve in the future. The overall soil erosion moduli of the YGP decrease by 196.86, 367.03, and 391.72 t/(km 2 ·a) under the scenarios of SSPs1-1.9, SSPs2-4.5, and SPPs5-8.5, respectively. (ii) Spatially, soil erosion in the southwestern and central-northern parts of the YGP will be significantly improved in the future. The soil erosion moduli of the karstic and non-karstic areas gradually become close to each other, with the difference in soil erosion moduli between them in SSPs1-1.9, SSPs2-4.5, and SSPs5-8.5 being reduced from 671.65 t/(km 2 ·a) to 623.79, 592.21, and 611.92 t/(km 2 ·a), respectively. (iii) Among the different SSP scenarios, the SSPs2-4.5 scenario aligns most closely with the principles of sustainable development, making it the most desirable pathway. To ensure the long-term effectiveness of soil erosion control under changing climate and socioeconomic conditions, future strategies should take the SSPs2-4.5 scenario as a core reference and implement resilient portfolios of mitigation measures.