塔里木盆地南缘绿洲植被生境质量变化的研究——以策勒县为例

Studies on the Vegetation Variations of CeleOasis in the South of Taklamakan Basin

本文主要研究目的是以策勒研究区 1 990年的 LANDSAT TM图像和 1 998年的SPOT- HRV图像为基础底料编制规一化植被指数图 (NDVI) ,并根据极端干旱区绿洲特有的生态特征和已有的研究成就 ,找出植被指数灰度级与盖度级的对应关系并把规一化植被指数 (NDVI)转换成植被盖度图 ,最终利用植被盖度数字图像所提供的各盖度级的数量和空间分配状况来评价 90年至 98年期间植被环境质量的变化 。

The main purpose of the paper is to workout NDVI according to LANDST TM image of 1990 and XI multi-spectral SPOT image of 1998 in Cele. Based on the ecological characters of arid oasis and its research achievement, corresponding relations of plant index grade and cover grade were found and NDVI was transformed into plant cover graph. Finaly, variations of vegetation environment quality from 1990 to 1998 was evaluated according to distribution of quantity and space condition rendered by plant cover digital images, and exploiting and managing ways were pointed out. By comparing 2 period of plant cover grade images with local statistic materials, the paper pointed out that the trend of sandy desertification in Cele oasis derived from the two important reasons which are severe influences of nature and humanity. So, in order to ameliorate the local ecological environment, people lived in Cele country should esteblish well developed shelter-belts to preserve their homeland and reduce the degree of sandy wind offensive, develop social economy, carry out sustainable development.