基于RDVI的尉犁绿洲植被覆盖动态变化研究

植被覆盖度是绿洲生态环境变化的最重要标志之一。本文在尉犁地区地形图数字数据和土地利用图数字数据的基础上 ,通过遥感技术 ,使用不同年份同一季相的 TM图像数据为基础底料编制重规一化植被指数图 ( RDVI) ,根据尉犁绿洲的生态环境特征 ,并结合实地调查分析的结果 ,研究植被指数灰度级与盖度级的对应函数关系 ,将其转换成植被覆盖度图。最终利用植被覆盖度度度图像所提供的各盖度级的数量和空间分配状况来评价图像所包括时段 ,即 1 991年至 2 0 0 0年期间植被环境质量的变化 ,并阐明原因 ,为该区域的生态环境综合治理提供科学方法和依据。

Study on Dynamic Change of Yuli Oasis Plant Cover Based on RDVI

Plant cover is one of the most important sign of oasis ecological environment change.The main purpose of the research was to workout RDVI according to LANDSAT TM image of same season of l991 and 2000 in Yuli,on the basis of the digital relief map and digital land use map of Yuli County.On the foundation of ecological character of arid oasis and research achievement,corresponding relations of plant index pixel grade and cover grade were found and RDVI was transformedinto plant cover image.Finally,variation of vegetation environment quality from 1991 to 2000 was evaluated according to distribution of quantity and space condition rendered by plant cover digital image, and exploiting and managing ways were pointed out.Comparing the two period plant cover grade images with local statistics materials,it was pointed out that the development of Yuli oasis sandy desertification was controlled by two importment factors which were severe influences of nature and humanity.Therefore,in order to ameliorate the local ecological environment,people lived in Yuli County should work hard to plant numerously to preserve their hometown and reduce the degree of sandy wind offensive,develop social economy.