关键词: NDVI, 盖度图像, 盖度级, 覆盖类型

Abstract: The main purpose of the paper is to workout NDVI according to LANDSAT TM image of 1990 and XI multi-spectral SPOT image of 1998 in Qira.In the foundation of ecological character of arid oasis and research achievement,corresponding relation of plant index pixel grade and cover grade are found and NDVI is transformed into plant cover graph.Finally,variation of vegetation environment quality from 1990 to 1998 is evaluated according to distribution of quantity and space condition rendered by plant cover digital image and exploiting and managing ways are pointed out.Comparing the two period plant cover grade images with local statistics materials,the paper points out that the development of Cele oasis sandy desertification is controlled by two important reasons which are severe influences of nature and humanity.Therefore,in order to ameliorate the local ecological environment,people lived in Cele County should work hard to plant numerously to preserve their hometown and reduce the degree of sandy wind offensive,develop social economy.

Key words: NDVI, cover image, cover grade, coverage type