卫星遥感技术在永定河流域(河北)土壤侵蚀调查评价中的应用研究

The Application of Satellite Remote Sensing Technique on The Survey of Soil Erosion In Northwest Hebei

利用 Landsat- 5TM图像 ,在分析土壤侵蚀影响因素的基础上 ,首先进行与土壤侵蚀相关密切的各单项要素的解译 ;其次 ,以土壤侵蚀在 TM图像上的综合反映为标志进行基本侵蚀图斑的综合解译 ;第三步通过选定的土壤侵蚀强度评判模型 ,对每个基本侵蚀图 ,由不同权重的各单项要素给出其分值 ,最后根据综合分值确定每个图斑的土壤侵蚀强度等级。研究结果表明 ,冀西北地区土壤侵蚀是非常严重的 ,以轻度侵蚀为下限的侵蚀区面积占全区面积的 65%。两大地貌单元区相比 ,盆地区更严重于山地区。但多时相对比研究也表明 ,近十几年的治理工作取得了明显成效 ,土壤侵蚀的总趋势是向减缓方向发展。

On the basis of analyzing all the factors effectting soil erosion,first,each factor relative to soil erosion is interpreted using landsat\|5TM image.Second,all basic erosion pattern spots are interpreted according to comprehensive features of soil erosion on TM image too.Third,for each basic soil erosion pattern spot,through a multi\|factor judgment model used for judgemet soil erosion degrees,a numerical value representting soil erosion degree of the spot is worked out by all the factors on the spot with different weight on soil erosion.Final,all the spots obtain their numerical value,and the degrees of all the spots are determined by the value.The study result shows that the soil erosion in Northwest Hebei is very seriously.With the exception of slight degree,the total areas of the others different kinds of erosion degrees account for 60.5 per cent of the whole area.The soil erosion of the basin areas is more serious than the mountain areas.Multi-temporal comparison analysis has discovered that the general trend of soil erosion is weakening because of continued soil erosion control for over ten years.