基于遥感生态指数的上海南汇东滩海岸带湿地生态格局变化评价

Evaluation of ecological pattern change of Nanhui Dongtan wetland in Shanghai based on remote sensing ecological index

摘要:

海岸带湿地作为海陆系统的交错地带，生态功能日益凸显。然而，近年来沿海发达城市为满足经济的高速发展，大规模围垦开发严重挤压了海岸带区域的生态空间。以上海南汇东滩湿地为研究对象，取2000、2006、2012和2018年共4期的Landsat遥感影像，借助遥感生态指数（remote sensing based ecological index，RSEI）对研究区生态格局进行客观、定量、可视化的监测与评价。结果表明：（1）2000、2006、2012和2018年RSEI指数均值分别为0.295、0.227、0.405和0.489，进一步分级处理后，发现研究区生态环境质量主体由“较差”上升为“良好”，“优”与“较优”等级均有所增加，湿地生态环境质量略向好的方向发展；（2）对2000—2018年间RSEI指数进行差值变化检测，研究区内生态环境状况“变差”、“不变”、“变好”的面积占比分别为12.41%、53.32%和34.27%，以“不变”为主；（3） RSEI可以较好地反映2000—2006与2012—2018年间人类活动造成的海岸带生态频繁变化的现象，具体表现在RSEI指数明显减小与增大，该结果显示RSEI指数对南汇东滩湿地生态分析具有一定适用性。通过生态格局变化的可视化表达，可以较好揭示城市海岸带湿地生态演化进程，避免生态风险，实现城市可持续发展和科学管理。

Abstract:

As a staggered zone of land and sea system, the ecological function of coastal wetland is increasingly significant.However, in recent years, in order to maintain the rapid economic development, developed coastal cities have carried out large-scale reclamation and development, which has seriously compressed the ecological space of coastal zone. Taking the Dongtan wetland in Nanhui, Shanghai as the research object, Landsat remote sensing images were taken from 4 issues in 2000, 2006, 2012 and 2018, and based on the remote sensing ecological index(RSEI)to monitor and evaluate the ecological pattern of the research area in an objective，quantitative and visual way. Results show:(1)The mean of RSEI in 2000，2006，2012 and 2018 is 0.295, 0.227, 0.405 and 0.489. After the classification treatment, it was found that the ecological environment quality in the study area rose from “poor”to “good”, and both “excellent”and “better” increased, which shows the ecological environment quality of the Dongtan wetland was slightly improved.(2)According to the image differencing method of RSEI between 2000 and 2018, the area proportion of the eco-environmental status in the study area of “degradation”,“no change”and“improved”is 12.41%,53.32% and 34.27%, and main body is“nochange”.(3)The RSEI has suitability to Dongtan wetland. Through the visual expression of the change of ecological pattern, the ecological evolution process of urban coastal wetland can be better revealed, and avoid some ecological risks，to achieve sustainable development of cities and scientific management.