鄂东北土壤侵蚀时空演变及其影响因子定量评价

为定量揭示鄂东北土壤侵蚀时空演变特征及其影响因子的贡献，基于RUSLE模型和2000—2020年遥感影像数据探究土壤侵蚀强度的时空变化，并结合地理探测器模型识别土壤侵蚀主导因子及其交互作用效应。结果表明：2000—2020年鄂东北土壤侵蚀模数呈波动减小趋势，2020年的土壤侵蚀模数较2000年下降62.82%；侵蚀强度以微度和轻度侵蚀为主，二者面积之和占总侵蚀面积的82%以上；微度侵蚀面积占比上升，轻度、中度、强烈、极强烈和剧烈侵蚀面积占比呈波动下降趋势；中部和东北部土壤侵蚀明显改善，东北部土壤侵蚀模数仍较高；耕地是土壤侵蚀的主要地类，其土壤流失量占总流失量的74.82%~82.42%；15°~35°坡度区间分布着69.33%的极强烈侵蚀土壤和85.55%的剧烈侵蚀土壤；土壤侵蚀影响因子解释力（q值）表现为植被覆盖度>坡度>海拔>土地利用类型>降雨，植被覆盖度是影响鄂东北土壤侵蚀变化的主要因子，植被覆盖度和坡度之间的交互作用对土壤侵蚀强度的解释力最大（32.28%）；植被覆盖度小于0.3和坡度大于35°的区域发生土壤侵蚀的风险最高。近20年间鄂东北土壤侵蚀明显改善，这主要得益于封山育林、退耕还林等水土保持措施的实施以及多因子协同治理。

Spatiotemporal evolution of soil erosion and quantitative evaluation of its influencing factors in northeast Hubei

To quantitatively reveal the spatiotemporal evolution characteristics of soil erosion and the contribution of its influencing factors in northeast Hubei, the spatiotemporal changes in soil erosion intensity were explored based on the RUSLE model and remote sensing image data from 2000 to 2020, and the dominant factors and interaction effects influencing soil erosion were identified using the geodetector model. The results showed that the soil erosion modulus in northeast Hubei exhibited a fluctuating decreasing trend from 2000 to 2020. The soil erosion modulus in 2020 decreased by 62.82% compared with that in 2000. The erosion intensity was dominated by slight and mild erosion, and the areas of the two erosion intensities accounted for >82% of the total erosion area. The proportion of slight erosion increased, and the proportion of mild, moderate, strong, extremely strong and severe erosion showed a fluctuating downward trend. The soil erosion status in the central and northeastern regions was significantly improved, and the soil erosion modulus in the northeastern region remained high. Cultivated land is the main land type of soil erosion, and its soil loss accounts for 74.82%–82.42% of the total loss. Strong and severe erosion accounted for 69.33% and 85.55%, respectively, in the slope range of 15°–35°. The explanatory power（q）value of soil erosion influencing factors is expressed as vegetation coverage > slope > altitude > land use > rainfall. Vegetation coverage was the main factor affecting the change in soil erosion in northeast Hubei, and the interaction between vegetation coverage and slope had the greatest explanatory power for soil erosion intensity（32.28%）. Areas with vegetation coverage <0.3 and slopes >35° had the highest risk of soil erosion. In the past 20 years, the soil erosion in northeast Hubei has clearly improved, which is mainly due to the implementation of soil and water conservation measures such as closing hillsides to facilitate afforestation and returning farmland to forests, and multi-factor collaborative management.