Integration of remote sensing data and GIS for diagnosis of coastal ecosystem degradation: A case study of Chongming Dongtan wetlands, Shanghai, China

Along with rapid urbanization and economic growth in China, intensified land use has resulted in large-scale loss of wetlands area and ecologic service functions. This study was conducted in Dongtan wetlands on the eastern shore of Chongming Island in Shanghai in eastern China, which is the largest island found in the Yangtze River estuary. Remote sensing images and field observation data were applied to diagnose the degradation of Chongming Dongtan wetlands ecosystem, by constructing a Health Distance (HD) model on the platform of GIS. The results indicated that the eastern part of the wetlands showed a relatively healthy condition and became the most suitable habitats for rare water birds and migratory birds, while the northern and southern parts were diagnosed as subhealthy and unhealthy and exhibited symptoms of degradation, mainly due to the consequences of human activity. The findings provided baseline information for sustainable use of coastal resources and effective ecological protection and restoration, and demonstrated the feasibility and effectiveness of the integration of remote sensing and GIS with field data for habitat mapping and large-scale ecological assessments of coastal ecosystem.