China National Surface Weather Station (CNSWS) version 3.0 dataset

We used daily precipitation data from the China National Surface Weather Station (CNSWS) version 3.0 dataset, available at https://data.cma.cn. The CNSWS network spans the entire country, with more than 78 meteorological stations situated within the alpine canyon region of southwest China. This dataset includes daily records of key meteorological variables, such as precipitation, evaporation, and relative humidity since 1960. For this study, we used daily precipitation data from 38 carefully selected stations covering the period from 1980 to 2019 were used. Two primary criteria guided the station selection: (1) data reliability to ensure consistency and accuracy in the time series and (2) geographical representativeness to capture variability in elevations and erosion-sensitive zones within the study area. Each station reports daily rainfall totals for a 24-hour period from 12:00 p.m. on the previous day to 12:00 p.m. on the current day, following CNSWS standards. In this context, stations with significant data gaps or inconsistent records were excluded to ensure temporal reliability. A detailed list of the station metadata is provided in Supplementary Table S1. To ensure data integrity, daily precipitation values underwent a quality control process as described by Shen et al. (2014), focusing on completeness, continuity, and anomaly detection. The spatial distribution of the selected stations reflects the complex terrain and ecological zones of the region, covering both lowland and highland areas, which are critical for understanding soil erosion.