基于TM影像的沙化土地动态变化研究——以榆林市榆阳区河口水库周边地区为例

TM Image Based Study on Dynamic Changes of Land Desertification——A Case Study on Hekou Reservoir Area of YuLin City

以榆林市榆阳区河口水库周边地区1999年和2004年两期TM影像为基础数据,在ERDAS IMAGINE平台上,通过对研究区遥感影像进行预处理、建立解译标志、人工判读并分类等,得到了河口水库周边地区沙化土地动态变化分布图。结果表明,1999年到2004年期间,河口水库水域面积明显增大。周边5km范围内,沙化土地明显逆转,部分流动沙地和半固定沙地向固定沙地转化,使耕地面积减少,林地增加。

Taking two sets of TM images of Hekou reservoir area acquired in 1999 and 2004 as the basic data, through conducting the remote sensing image pre-processing on ERDAS IMAGINE platform, establishing interpretation keys, reading manually, classifying and carrying out other procedures, we have obtained the distribution map of desertification dynamic changes of Hekou reservoir area. The study result shows that from 1999 to 2004, the total water area of Hekou reservoir increased notably, the desertification within its 5km surrounding area reversely changed evidently, part of the flowing sandy land and semi-flowing sandy land transformed into immobile sandy land, the area of arable land decreased and the forest area increased. The area of the flowing sandy land decreased in think such a situation is mainly caused by human factors.