文章应用EOS-MODIS数据对松嫩平原的荒漠化问题进行了研究。首先计算出标准化植被指数(NDVI)和植被覆盖指数(VCI),反演求得荒漠化指数(D1),得到荒漠化面积;采用多种方法和复杂步骤,首次获得了松嫩平原碱质荒漠化、沙质荒漠化的面积,分别为160.30×10^4hm。和50.56×10^4hm^2,分别占该区面积的24.35%和7.84%;应用数字高程模型(DEM)对荒漠化的分布规律和成因进行了分析和讨论,指出松嫩平原以碱质荒漠化为主,当前荒漠化的发展程度已处于临界状态,对区域可持续发展构成了严重威胁,亟需采取行之有效的防治措施。
In the past ten years, based on the RS data from TM/ETM satellite and the 3S technique, the formation and distribution of the salinization and alkaline desertification (AD) of the Songnen Plain caused by such factors as climate, human culture and global changes and so on had been studied. Based on these analyses, EOS - MODIS data were applied to the macroscopical study on desertification of the Songnen Plain in this paper. The red band and near infrared band of MODIS were suitable to monitor and analyze the surface vegetation activity. Vegetation Coverage Index (VCI) was calculated by Normalized Difference Vegetation Index (NDVI), then Desertification Index (DI) was obtained by inversion and was used in the desertification study. The results showed that the area of desertification in the Songnen Basin was 351.14×10^4hm^2 , which accounted for 15.18% of the total area. As to the hinterland in the plain, the desertification area was 210. 86×10^4 hm^2 , and 32.21% of the hinterland. As MODIS -NDVI data could not identify AD and sandy desertification(SD) directly, it was put forward in the paper that the method of supervised classification and unsupervised classification to use MODIS image to interpret AD and SD. The results showed that the AD area in the hinterland was 160. 30 ×10^4hm^2 , which accounted for 24.35% of the area, and SD area was 50. 56×10^4hm^2, and accounted for 7.84%. In addition, Digital Elevation Model (DEM) was used to analyze the distribution of desertification and to discuss the formation cause and development trend as well.