三江平原不同流域水土流失变化特征分析

Soil Erosion Change Characteristic of Different Watersheds of Sanjiang Plain during the Past 50 Years

运用地理信息系统(GIS)结合美国通用水土流失方程(USLE),根据研究区现状合理选择USLE中水土流失各因子的计算方法,求算出三江平原1954年、1976年、1986年以及2000年的水土流失状况图。通过与2000年遥感普查结果进行对比,验证了方法的有效性。分别对三江平原六个流域水土流失变化情况进行分析,认为土地利用方式对水土流失有重要影响,农田开发是造成水土流失面积增加、强度增强的主要原因。土地垦荒活动强度降低以及部分旱地改种水田后,水土流失面积增加的幅度明显下降。

By reasonable selection of different factors in the Usual Soil Loss Equation （USLE）, the serial of soil erosion maps of Sanjiang Plain in 1951, 1976, 1986 and 2000 are obtained under the support of GIS. The calculated result is approved to be valid comparison with the result of the second remote sensing survey for soil erosion of China in 2000. Then the change of soil erosion of the 6 watersheds in the Sanjiang Plain is analyzed to indicate that the way of land use impacts soil erosion significantly, and the reclamation is the main reason for the area increase intensity and of the soil erosion. The expansion rate of soil erosion slowed down obviously after the reduce of wasteland reclamation and replanting some dry land to paddy field.