【摘要】 为探讨北方土石山区土地利用/覆被的变化对土壤侵蚀的影响,作者基于RUSLE和土壤侵蚀强度指数,分析1990—2015年北京市潮白河流域土地利用/地表覆被变化特征,模拟区域内不同时期不同土地利用/覆被情况下的土壤侵蚀变化规律。结果表明:1990—2015年,在相同的植被盖度等级下,耕地—林地转化区和耕地—草地转化区的土壤侵蚀模数呈减少趋势,均值分别减少362. 32 t/(km2·a)和259. 54 t/(km2·a),而林地—草地转化区的土壤侵蚀模数均值呈增加的趋势,为230. 94 t/(km2·a)。总体来看,北京市潮白河流域内林地和草地的土壤侵蚀强度指数大于耕地,并在2005年达到最大值,分别为201. 57和190. 10。这主要是林草地质量退化致使土壤侵蚀等级较高区域的面积较大,尽管耕地向林草地转移减少了部分侵蚀,但林草地区域的土壤侵蚀防治仍不可忽视。该研究成果有望为北京市山区土地资源的优化配置和有效控制土壤侵蚀提供一定的应用参考。更多还原

【Abstract】 [Background]Regional soil erosion changes are highly correlated with changes in land use/cover,but the influence of land use/cover changes on the soil erosion is different in various regions. A large number of related researches have been carried out in the Loess Plateau and the southern red soil area,but the studies on the northern soil and rock mountain areas are relatively less. However,the soil erosion in the northern soil and rock mountain areas is also serious,and most of them are caused by land use/cover change. Therefore,it is significant to explore their influences of land use/cover changes on the soil erosion to offer the references of land use planning and water and soil conservation for the government. [Methods]This study selected Chaobai River Basin in Beijing as study area. Using 30-year average annual rainfall data,soil attribute data,high-resolution DEM data,besides various years’ remote sensing data and land use data,and the experimental methods of RUSLE and soil erosion intensity index methodology were applied to estimate the tempo-spatial distribution of soil erosion and soil erosion intensity index of the Chaobai River Basin in Beijing. On the above basis,the changes of soil erosion under different land use/covering conditions in different periods were finally calculated. [Results] The soil erosion modulus in the cropland to forestland conversion area and the cropland to grassland conversion area under the same coverage grade condition showed a decreasing trend,and the mean decreased by362. 32 t/( km2·a) and 259. 54 t/( km2·a) from 1990 to 2015,while the soil erosion modulus in the forestland to grassland conversion area showed an increasing trend of 230. 94 t/( km2·a). However,the soil erosion intensity index of forestland and grassland in the Chaobai River Basin of Beijing was overall greater than that of cropland,and reached the maximum in 2005,which were respectively 201. 57 and190. 10. This was mainly because the degradation of forestland and grassland quality resulted in soil erosion deterioration. Although the transfer of cropland to forestland and grassland reduced part of the erosion,the soil erosion control in forestland and grassland areas cannot be ignored. [Conclusions]The research results can provide a certain technical reference for realizing the optimal allocation of land resources in Beijing mountainous areas and effectively controlling soil erosion. The government should not only pay more attention to the prevention and control of soil erosion on sloping cropland,but also strengthen the supervision of soil erosion on low-efficiency plantations with low coverage and incomplete vertical structure,and grassland erosion in the early stage of returning cropland and unmanaged grassland after abandoned tillage.更多还原