基于NDVI-Albedo特征空间的沙漠化动态变化研究——以准格尔盆地南缘为例

土地沙漠化是干旱区主要生态环境问题之一,也是干旱区农业发展的重要制约因子。以新疆农八师石河子垦区150团为研究区域,基于TM遥感影像,计算了归一化植被指数(NDVI)、地表反照率(Albedo)等指标,通过建立NDVI—Albedo特征空间,对研究区沙漠化的等级进行划分。将研究区的沙化土地分为极重度、重度、中度、轻度沙漠化土地,并通过地面调查验证,对其精度进行了评价。对2000,2005和2010年3期数据进行分类处理,并对这3期的沙漠化信息进行了分析。结果表明,利用该方法的分析精度满足研究要求;研究区通过10a的发展变化,其沙漠化状况得到了有效改善。

A Study on Dynamic Changes of Desertification in South Edge of Junggar Basin Based on NDVI-Albedo Features

Desertification is not only one of the most serious ecological environment problems but also the limiting factor of the development of agriculture in arid areas. This paper took the area of 150 regiment in Shihezi City of Xinjiang Uyghur Autonomous Region as the study area, and used TM images to derived the normalized difference vegetation index(NDVI) and surface Albedo, and to classify desertification grade of study area by establishing NDVI-Albedo feature space. Desertified land in the study area can be divided into very severely desertified, severely desertified, moderately desertified, and mild desertified. The accuracy of the monitoring was tested with the ground investigation, and the result showed that the accuracy meet the requirement of the study. With the same method, we classified desertification area in 2000, 2005 and 2010, and analyzed the dynamic changes of desertification three periods. The analysis showed that the development of desertification has been effectively controlled after 10 years.