哈密地区绿洲植被遥感监测及其变化原因分析

植被作为生态环境的重要组成部分,是人类生存环境变化的一个敏感指示变量.选取2002-2005年连续4年7月份的MODIS 250 m×250 m的遥感影像,在EOS/MODIS资料接收处理系统、卫星遥感应用系统平台以及 MAPGIS6.5的支持下,通过预处理、几何校正、归一化植被指数(NDVI)提取以及最大值合成,对东疆哈密地区的植被盖度进行了计算,并按 NDVI 值的大小将地表植被分为3类,计算出了不同植被覆盖的面积,比较了逐年不同盖度植被的面积变化,结合哈密地区的资源分布图进行比较,研究表明:哈密地区2002-2005年低覆盖的植被盖度减少较快,且该区域大多为牧草地,这也说明在那些原本就是低植被覆盖的牧草地区域,脆弱的生态环境正遭受到不断的破坏,正在走向沙化、荒漠化,这主要是由于降水量、人为因素以及载畜量所造成的.

Vegetation remote sensing inspection and analysis of the cause of vegetation change in Hami Oasis

Vegetation as an important part of environment was a sensitive variable indicating the change of the survival environment of human being.Choose a consecutive 4 years Modis data,250 m resolution image of July since 2002 to 2005;based on the EOS/MODIS data incept and dispose system,satellite remote sensing application system and MAPGIS6.5,by using pre-processing,geometry rectification,extract NDVI and composite the maximum value;after that,calculate the vegetation coverage in Hami region,and divide the vegetation into three parts according to the value of NDVI,and got the area of different vegetation coverage.Moreover,compare them with the resource distribution chart of Hami region and the results showed that: the cover of low vegetation coverage area reduced quickly,because this area mostly belonged to grassland,it showed that the brittle environment was suffering continuous destroy.These low vegetation coverage areas were lean to desertification.We concluded that the rainfall, human factor and flock rate had the main influence on it.