中文摘要：

利用LandsatTM遥感卫星影像反演植被指数和地表反照率，并由此构建了植被指数和地表反照率组成的特征空间，最后利用该特征空间对张掖绿洲及其附近区域的沙漠化现状和程度进行了定量评价。利用野外调查的定位数据对结果进行检验，总体精度达到82％。该方法可以在遥感图像处理软件下实现沙漠化现状与程度的自动识别，而且指标简单、易于获取。与单纯使用遥感光谱信息进行分类相比，对于沙漠化现状与程度的分类和分级具有更好的效果。

英文摘要：

In this study, the Landsat TM image of Zhangye Oasis and its adjacent areas were used to retrieve the vegetation index and land surface albedo. A spectral feature space composed of normalized difference vegetation index and land surface albedo was construeted to evaluate present status and degree of desertification quantificationally. The classification error was evaluated by the data acquired from field survey. It indicated that the method was helpful to the extraction of desertification and the overall accuracy of about 82% was satisfying. Compared with the classifying method of only using spectrum information, the method using NDVI-albedo feature space produces a better effect on the classification of the present status and degree of desertifieation, and the result was tested.