基于南京市1988年和1998年两期TM影像,首先用辐射水准归一化法将1998年影像校正到1988年影像的辐射水平上,再经过几何校正、训练区纯化等预处理,对两期影像分别用最大似然法进行分类,然后在Arc/Info的GRID模块中编写AML语言,对得到的两期土地利用分类图进行叠置运算,提取出土地利用动态变化信息。分析结果表明,10a间南京市耕地面积大量减少,林地面积有所增加。
This research was carried out with two phases of remotely sensed images covering Nanjing City in 1988 and 1998 respectively to monitor the land use change. At first, two images were normalized at the same radioactive level of 1988's TM image, registered with high geometric accuracy less than 0. 5 pixel errors and purified training regions, after pretreatment of TM data. Then maximum likelihood classification is applied for both images. Finally the GRID model of Arc/Info software is used to algebraically calculate two classified maps with AML codes and obtained information of land use change. Through analyzing the result indicates that in the past period of ten years arable land decreased largely was mainly due to urban extension, and forest increased was due to some protective policies and activities of forestation.