Spatial-temporal pattern of cropland soil erosion in China over the past four decades

        China’s croplands are facing serious threats of soil erosion, calling for long-term and spatially-explicit assessment to ensure food security and sustainable agricultural development. However, the complexities of topographical, meteorological, and land cover and management factors, which are key determinants of soil erosion, pose big challenges for estimating cropland-related soil erosion in China over an extended time span, especially across diverse agricultural regions and different crop types. 
        To address this issue, this study combines the Revised Universal Soil Loss Equation model with high-resolution remote sensing datasets to investigate the temporal-spatial evolution of crop-specific soil erosion in China from 1980 to 2018 at a 30 m resolution. When calculating the RUSLE factors, in addition to using well-established methods that have been validated in national and global studies to calculate the crop-specific land cover and management factors for croplands, efforts were made to localize the rainfall erosivity factor and the support practice factor. The rainfall erosivity factor was calculated using a rainfall erosivity model derived from daily rainfall data observed at China’s meteorological stations, coupled with a more accessible global daily rainfall raster dataset. Furthermore, the support practice factor for croplands was categorized based on slope, which could reflect the relationship between cropland topographical characteristics and the benefits of soil and water conservation. 
        The results show that about 60% of China’s croplands experienced slight erosion over the past four decades. Regions with strong and severe erosion intensity are predominantly located in the southern provinces. However, due to the agricultural policy implementations, agricultural shifts, and variations in crop planting patterns, it was revealed that soil erosion intensity in most regions has shown a downward trend. Specifically, in terms of agricultural zoning, the cropland soil erosion rate in the Sichuan Basin has decreased sharply. Moreover, different crop types exhibited differentiated spatial patterns in the cropland-related soil erosion rates. Overall, grains exhibit the highest erosion intensity, while fiber crops have the lowest.
        In summary, this study constructed a high-resolution, long-term dataset of cropland soil erosion in China and analyzed its temporal-spatial dynamics and influencing factors. The outcomes can help facilitate a more comprehensive understanding of soil erosion mitigation and provide a solid foundation for sustainable agricultural production.