【摘要】 选取都江堰市2007年9月18日和2008年7月18日两个时相的TM数据,在辐射校正相关理论的指导下,对遥感影像进行辐射校正,主要是将图像的DN值转换为表观反射率,再使用归一化植被指数(NDVI)对图像进行密度分割、分类等处理,提取植被盖度信息。根据区内植被发育特点,将之分为无植被覆盖、低植被覆盖、中植被覆盖和高植被覆盖4级,通过震前和震后对比分析,研究发现地震活动的强弱直接导致了区内植被盖度不同程度的变化。更多还原

【Abstract】 TM remote sensing data of September 18,2007 and July 18,2008 were collected in the view of radiation correction theory by first doing remote sensing images radiation correction which can changes DN value to the apparent reflectance,then using NDVI processing to do density partition and classification,and finally getting the vegetation cover information.Considering the vegetation characteristics,classifying vegetation cover into none,low,medium and high four categories.The research showed that Wenchuan Earthquake has made huge effects on vegetation coverage change.更多还原