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在RS与GIS支持下,选用RUSLE模型估算土壤侵蚀量,利用转移矩阵分析土地利用及土壤侵蚀变化特征,引入土壤侵蚀强度指数分析土壤侵蚀效应,在此基础上,对88子流域进行回归分析,建立土地利用结构与土壤侵蚀定量关系。结果表明:1986～2010期间,研究区土地利用类型以耕地为主且呈减少趋势由63%减少到59%,土地利用类型变化主要由耕地和草地向其他地类转出为主;土壤侵蚀状况有所好转,侵蚀类型以微度为主,所占比例由60.7%上升到61.7%,强度以上所占比例由16.9%降到16.6%,土壤侵蚀等级变化显著,中度、强度和极强度变化率为50.54%、50.8%和47.34%,主要由较高强度和邻近较低强度转入为主;土壤侵蚀强度随土地利用类型变化而变化,当发生不合理变化由林地→耕地时,侵蚀强度指数由154.3增到259.3,结构合理化由耕地→林地时,侵蚀强度指数由233.2降到145.1;回归方程结果显著,检验误差为0.024%,有一定可靠性。因此,优化土地利用结构是控制土壤侵蚀的有效途径,通过建立土地利用结构与土壤侵蚀量的定量关系可为动态监测土壤侵蚀状况提供简单方法。
With the support of RS and GIS, the RUSLE model was used to estimate the amount of soil erosion, the transfer matrix was used to analyze the characteristics of land use and soil erosion, and the soil erosion intensity index was introduced to analyze the soil erosion effect. On this basis, Establishing quantitative relationship between land use structure and soil erosion. The results showed that during the period from 1986 to 2010, the land use types in the study area mainly consisted of cultivated land and decreased from 63% to 59%. The change of land use types was mainly from cultivated land and grassland to other land types; the soil erosion status As a result, the erosion types are mainly micro-degree, with the proportion increasing from 60.7% to 61.7% and the proportion above the intensity decreasing from 16.9% to 16.6%, and the soil erosion level changes significantly with moderate, intense and extremely strong The rates of change were 50.54%, 50.8% and 47.34%, respectively, which were mainly transferred from higher intensity and lower adjacent intensity. The intensity of soil erosion changed with the change of land use types. When irrational change occurred from forest land to cultivated land, erosion The intensity index increased from 154.3 to 259.3. When the structure was rationalized from arable land to woodland, the erosion intensity index decreased from 233.2 to 145.1. The regression equation was significant with the test error of 0.024% and a certain degree of reliability. Therefore, optimizing land use structure is an effective way to control soil erosion. By establishing quantitative relationship between land use structure and soil erosion, a simple method for dynamic monitoring of soil erosion can be provided.