The soil erosion in Datong River basin was estimated and quantitatively evaluated in order to provide a scientific and rational basis for soil and water conservation and environmental protection of the basin. Based on the revised universal soil loss equation(RUSLE), supported by remote sensing and geographical information system techniques, the situation of soil erosion in Datong River basin was estimated, and the differences in soil erosion under different land use types and different slope was discussed. The results showed that the erosion area in Datong River basin was 12683.66 km2, accounting for 83.83% of the total basin area, and the annual mean soil erosion modulus was 6274.76 t/km2. The erosion intensity was overall dominated by micro and slight degree erosion. Soil erosion was mainly concentrated in the grassland, whose erosion area accounting was up to 55.50%, followed by shrubbery. In the range of 0~25° slope, the soil erosion area increase with the increase of slope gradient until to a certain value, after which the erosion area decreased, but reaching the maximum value when the slope gradient greater than 25° . The micro degree erosion occurs mainly in the range of 0~10° slope, and the area of moderate erosion and above all reached the maximum value when the slope gradient greater than 25°. Irrational human activities, such as excessive deforestation, overgrazing and urban sprawl were the main cause of soil erosion. And to moderately control human activities and to improve vegetation coverage were the focus of future water loss and soil erosion prevention in Datong River basin.%对大通河流域的土壤侵蚀进行估算和定量评价,以期为该流域的水土保持和生态环境保护工作提供科学合理的依据.基于修正的通用土壤流失方程(RUSLE),运用遥感和地理信息技术,对大通河流域土壤侵蚀状况进行估算,并探讨了不同土地利用类型和不同坡度下土壤侵蚀的差异性.结果表明,大通河流域土壤侵蚀总面积为12683.66 km2,占流域总面积的83.83%,年均侵蚀模数为6274.76 t/km2.侵蚀强度整体表现为微度侵蚀和轻度侵蚀.土壤侵蚀主要集中在草地,侵蚀面积占比高达55.50%,灌木林次之.在0~25°坡度范围内,侵蚀面积随着坡度的增大呈先增加后逐渐减少的趋势,但在>25°时达到最大侵蚀面积.微度侵蚀主要发生在0~10°坡度范围内,中度以上侵蚀等级的侵蚀面积均在>25°坡度范围时达到最大值.林草过牧滥伐、城镇无序扩张等不合理的人类活动是引起土壤侵蚀的主要原因,适度控制人类活动、提高植被覆盖率,是流域内今后土壤侵蚀治理及水土流失防治的重点.
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