我国低山丘陵区水土流失及生态环境背景分析

我国是一个以山地为主的国家，山地多为大江大河的源头，而低山丘陵为这些大江大河支流的发源地，这些区域的水土流失必然会带来环境问题。以TM影像为数据源，以GIS为技术支撑，从DEM中获取低山丘陵层，以此为MASK层，提取水土流失及相应的生态环境背景各层，包括土地利用、坡度、降水、均温、植被等生态背景层，这些背景层是多年数据的平均，然后把水土流失层与环境背景各层分别叠加，分析不同环境背景下水土流失状况，从而为治理水土流失提出科学依据。

Analysis of Soil Erosion Environment Background in China Hills

There is more than 70% mountains in China, and these mountains are the resources of rivers, such as the Yangtze River, the Yellow River.Moreover, these hills are resources of branches of main rivers.Soil erosion in these areas will lead to river environment change, and causes more disasters, such as flood.With RS and GIS supported, the authors analyse features of soil erosion environment background in these hilly areas, then some points are suggested for controlling soil erosion.The steps are as follows.First, extracting hill coverage from DEM with the elevation less than 1 000 m according to traditional method.Second, setting hill coverage as a mask in ARC/INFO to get environment background coverage, that is slope coverage, NDVI coverage, etc.Third, coming these coverages with soil erosion coverage in ARC/INFO.Some treatments for controlling soil erosion are presented.