基于遥感和GIS的黄土丘陵区土壤侵蚀变化监测分析--以静宁县水保世行贷款二期项目区为例

基于遥感融合影像和GIS技术,采用通用土壤流失方程RUSLE作为评价模型,计算了静宁县世行贷款二期项目区1998和2004年的土壤侵蚀量,并结合土壤侵蚀强度分级标准,生成土壤侵蚀强度等级图.结果表明,项目区2004年土壤侵蚀面积237 km2,侵蚀级别属强度侵蚀;项目区76.6%的泥沙来自于占总面积仅38%的极强度和剧烈侵蚀区域;6年间项目区平均侵蚀模数从1998年的9 559.4 t/km2下降到2004年的9 340.3 t/km2,侵蚀面积减少了1.62%;土壤侵蚀强度类型的主要转化过程是轻度和中度转化为微度.经分析,项目区25°以上的坡度土壤侵蚀量大于15 000 t/km2,是水土流失治理的关键;在不同的土地利用类型中,耕地侵蚀量最大.

Monitoring and analysis for soil erosion on Loess Hilly regions using GIS and RS--A case study of loess plateau Jingning project area

Based on merged remote sensing image and geographical information system technology,the model of soil erosion degree,the soil erosion amount of Jingning project area of Loess Plateau Watershed Rehabilitation Project was calculated.Results showed that:the annual average soil erosion amount in 2004 was 9 340.3 t/km~2 and it belonged to intensive degree erosion;Soil erosion intensity map was obtained according to the soil erosion intensity classification;the serious eroded area(sediment is higher than 10 000 t/km~2)was 38 %,but contributes 76.6 % sediments of total project area.The eroded area of project area decreased by 1.62% during the past six years.Soil loss on the land where slope was over 25,was more than 15 000 t/km~2,and it is the key factors to solution dealing with soil erosion.In different land use types,soil loss on farmland was nearly three times than on the woodland.The method of soil erosion investigation will provide quick,quantitative and scientific basic data for strategies of soil erosion prevention and soil protection.