The Ecosystem Health Assessment Of Dongtang Area In Chongming Island Based On RS And GIS

Nowadays, the global environmental change has become a worldwide hot issue. Since the major reason for global environmental change is the land use change and its effects to the ecological environment and ecosystem health issues naturally become the focuses of researchers. In this paper, we took Chenjiazhen-Dongtan area in Chongming Island as an study area to research the relationship between the land use and ecosystem. As typical of estuarine tidal wetland areas, Dongtan has typical comprehensive ecosystems, such as the estuaries, bays, wetlands, farmlands, towns, et al. Moreover, there are more and more human activities in Dongtan, and the confliction between the urban development and the wetland protection is becoming more and more serious. So, Dongtan becomes the ideal study area to study the relationship between the land use and ecosystem health.In this paper, the remote sensing (RS), geographic information system (GIS) and other mathematical methods and technologies were employed to study the ecosystem pattern in Dongtan area in Chongming Island, Shanghai. The Landsat TM images of 2000,2003,2005 and 2008 were applied to interpret and analyst the land use in respect year. With the technology of GIS, the land cover change, spatial ecosystem structure, land use transfer matrix, the dynamic change of the ecosystems and the fractal characteristics of the typical ground objects were calculated and analyzed based on RS. These analyses could reflect the comprehensive change of study area in the past 8 years. With the outputs, a multi-objective planning model was constructed integrating the economical benefits, social benefits and the ecosystem benefits. The model optimized the composition of the surface feature, and tried to seek the optimist sustainable development way of the ecological environment in the study area. In addition, the Cellular Automata-Markov (CA-Markov) model was applied to predict the land use change in the study area. As well, we also compared the land use change predicted by CA-Markov model and the multi-objective planning model. Finally, on the basis of ecological condition of the study area, the study area was divided into four typical ecosystems:urban, farmland, wetland and coastal area. At the same time, 8 factors were selected according to biodiversity, environmental pollution, economic output and other aspects of the study area. The criteria systems were constructed repetitively for the 4 typical ecosystems and the factors'weights were defined on the combination of experts estimation and index weights method. We evaluated the ecological health of the study area from patch scale and the regional scale respectively on the basis of the Pressure-State-Response (PSR) model.In addition, a Dongtan eco-management system was designed in this paper. It provided the functions of data query, statistical charts, thematic maps, layer annotation and so on. Moreover, it was a technology platform for decision-makers to decide the development of Dongtan area in Chongming Island.