南京市区土地覆被及生态环境遥感动态监测

Eco-environment Monitoring in Nanjing City Based on CBERS-2 and TM Image

随着城市的发展,城市的生态环境质量状况越来越引起人们的关注。以南京市区为研究区域,在对2000年TM和2004年的CBERS-2星进行影像特征分析的基础上,提取不同年份的土地覆被信息,进而分析土地覆被和生态环境的动态变化。得出如下结论:2000年土地覆被以居民地、水田和旱地为主,2004年则以居民地、旱地和林地为主,且水田大面积减少,居民地面积增加明显;土地覆被发生变化的部分以水田和旱地为主。从土地覆被类型变化率的角度,水田和公交建设用地变化最快,动态度分别为-8.61和5.17。不同类别之间的转化较为复杂,八大类别之间有20对转换关系(其中裸岩没有参与转换)。两年的生态环境质量值(EV)分别为:0.3871和0.3799,它表明南京市区的生态环境质量下降程度很小;生物丰度指数提高了10.43,说明南京市区生物丰富程度有很大改观;两年的植被覆盖指数相差较大,说明植被覆盖减少显著。

With urban development, the quality of eco-environment in city is being paid more and more attention. This paper takes Nanjing city as an example. On the basis of analyzing TM image in 2000 and CBERS-2 image in 2004, the land cover information in different years can be extracted by man-machine interaction. The result of a- nalysis of the variations of land covers and eco-environment show that in 2000, the main parts of land use are resi- dential area, paddy field and dry land while in 2004, the main parts are residential area, dry land and woodland. The paddy field reduces greatly and the inhabitant area increases obviously. The main parts of change in land use types are paddy field and dry land. In terms of changing rates of land covers, paddy field and transportation land change most quickly, and their dynamic degrees are - 8.61 and 5.17. The different category changes are com- plex, and 20 pairs of transformation relations exist in eight major classes （except naked rock）. The values of EV in these two years have been computed, being 0. 3871 and 0. 3799. The results show that eco-environmental quali- ty in Nanjing is descending slightly. Moreover, biological abundance index increases by 10. 43, indicating that the biological diversity changes a lot positively during four years. Vegetation cover index decreases by a big margin, indicating that the vegetation cover reduces obviously.