Hydraulic erosion-induced soil loss
critically undermines soil fertility, leading to vegetation degradation,
reduced crop yields, and increased flood and pollution risks, thereby
threatening food security, ecological integrity, and economic stability. Existing
soil erosion estimations using the Revised Universal Soil Loss Equation (RUSLE)
model are constrained by the absence of high-resolution (30 m) nationwide
rainfall data, significant spatial and temporal inconsistencies among
multi-source data, and limited regional adaptability of empirical RUSLE
parameters. To address these challenges, we developed the first 30 m resolution
Hydraulic Soil Erosion Dataset (CSWED) for Chinese mainland, spanning from 1990
to 2022. This was achieved by implementing a Random Forest (RF) interpolation
method to generate 30 m annual rainfall data and designing a multi-equation
combined vegetation cover management factor tailored to China’s diverse soil
characteristics. The mean absolute error (MAE) compared to the China Soil and
Water Conservation Bulletin was 9.48%, and the CSWED illustrates good
consistency with collected runoff plot observation data, significantly
surpassing the accuracy of existing publicly available datasets. Our analysis
reveals a predominant influence of slope length, steepness, and support
practice factors on soil erosion, coupled with a synergistic effect of
vegetation cover and topography. Notably, soil erosion in Chinese mainland
has exhibited an overall decreasing trend from 1990 to 2022, with significant
reductions in light, moderate, and severe erosion categories by 31.70%, 22.24%,
and 44.74%, respectively. Also, the sensitivity of soil erosion in 2022 was
dominated by strong sensitivity and moderate sensitivity, accounting for 74.149
% and 14.072 %. Then, the decrease in cropland area creates a decrease in soil
erosion of 123.54 t/hm2 from 1990 to 2022, while for every additional hectare
of forested area, soil erosion was reduced by 58.67 t. Special attention should
be given to the substantial expansion of soil erosion brought on by extreme
rainfall in the Middle and Lower Yangtze River (MLYR) and Southwest China
(SWC), where mean soil erosion was 11.71 t/(hm2 a) and 15.79 t/(hm2 a),
respectively, accounting for 60% of the national total.
Details at: https://www.sciencedirect.com/science/article/abs/pii/S0034425725000859