采用LandsatETM +多时相影像,在地类光谱特征分析的基础上,用分层分离的方法,提取出沙化土地信息。以全国沙漠化普查地类划分标准中的植被覆盖度为确定沙化土地程度的依据,通过建立NDVI和实测植被覆盖度的回归模型,确定不同程度沙化土地对应的植被覆盖度与NDVI的对应关系,用NDVI阈值进行划分,得到沙化土地程度图。 Using Landsat ETM + multi-temporal images, based on the analysis of the spectral features of the landform, the desertified land information was extracted by the method of stratified separation. To determine the degree of desertified land based on the national vegetation cover of desertified census land classification, the corresponding relationship between vegetation coverage and NDVI of different degrees of desertified land was established by establishing a regression model of NDVI and measured vegetation coverage NDVI thresholds are divided to obtain the degree of desertified land map.