洪泽湖湿地类型变化分析

以洪泽湖湿地为研究区，结合归一化植被指数（NDVI）、最优调节土壤植被指数(OSAVI) 和缨帽变换后的亮度指数（BVI）、绿度植被指数（GVI）、湿度指数(WVI)，基于知识规则对洪泽湖湿地进行分类试验。通过建立洪泽湖湿地分类的分类模型，以区分不同湿地类型，并利用1973年、1984年和2006年3个时相多波段MSS/TM数据对洪泽湖淡水湖泊湿地进行分类。结果表明：基于知识规则的分类方法简单易行，且易于剔除提取地物时的干扰信息；多种指数参与到分类中能够提高分类的总体精度；在1973—2006年这33年间，洪泽湖敞水区和湿地植被急剧减少，亟待采取有效的措施进行保护。

Analysis of long-term change in Hongze Lake wetlands

Wetlands have been paid great attention around the world for its particularity and importance in ecological environment,so nowadays wetland research has been in a hot field.Hongze Lake is rich in wetland resources and is of great significance in the regional eco-environment.In this paper,Hongze Lake was taken as the study area.Combining with normalized difference vegetation index(NDVI),optimized soil adjusted vegetation index(OSAVI) and the soil brightness vegetation index(BVI),greenness vegetation index(GVI),wetness vegetation index(WVI) of tasseled cap transformation.The classification has been carried out based on knowledge rules.By using classification model tailored for the classification of Hongze Lake wetlands,wetland types were effectively distinguished.Then the classification was applied to MSS and TM images of 1973,1984 and 2006 in Hongze Lake.The results showed that the classification method based on knowledge rules is simple and easy to eliminate interference information in classification.The use of the mentioned indices in decision model can increase the overall accuracy of classification.Our study showed that the coverage of open water and wetland vegetation in Hongze Lake drastically reduced over the past 33 years from 1973 to 2006.It is necessary to take effective measurements for the protection of Hongze Lake wetlands.