GIS Based Decision-making Support System Of Wetland Health Assessment

Located at the east of Chongming Island, Dongtan wetland is an ecological sensitive region of global importance. Interfered with human activities, its ecosystem health is faced with threat. So it is necessary to make quantitative research on its health assessment. This study took Dongtan wetland of Chongming Island as research area and selected indicators like topography and geomorphology, environment, biology and human interference according to press-stat-response model. Based on theory of ecosystem health, this study divided the health condition of research area into five levels and built an index system of wetland health assessment in Dongtan, Chongming Island. Combined with GIS and neural network model technologies, the study took grid as evaluation unit, and then established a neural network model of wetland ecosystem health assessment to quantitatively analyze the health conditions of Dongtan wetland. This model could provide decision-making support and scientific basis for rational utilization and protection of wetland sources. The dissertation consists of seven parts.Chapter one is a summary of various research on ecosystem health assessment on estuary wetland, as well as the effect and development of 3S technology to wetland ecological management. The research background and significance was supported by these theories and research methods were displayed in diagram.Chapter two is the theoretical basis of my research, including conception of ecosystem health, index system and health assessment methods. Principles and advances of estuary wetland research were also analyzed with the characteristics and health standards of estuary wetland. Theory of landscape ecology and its indices were under consideration in my research of health assessment index system.Chapter three addresses the characteristics of physical geography, biodiversity and ecological environment in Chongming Island. Meanwhile, emphasis was given on the structure and function of ecosystem, landform and vegetation evolution in Dongtan werland. Chapter four analyzes the restraint factors of wetland ecological health and current index system. Press-State-Response model was selected to build the health assessment index system of Dongtan wetland. All the indices were quantized and standardized.Chapter five is the technological support of my research. BP neural network was utilized to establish the distributed neural network model for health assessment on wetland ecosystem, after comparing with types, structures and principles of different artificial neural network. This model was applied on. Dongtan wetland and the result displayed the health conditions of Dongtan wetland in different areas from space. Generally, Dongtan wetland is comparatively health, but areas with better health condition occupied only 30% and others are in a general condition. Furthermore, the wetland ecosystem health has a descending trend. So, it is necessary to strengthen management of wetland and make a sustainable development of wetland ecosystem.Chapter six is the design and development of decision-making support system of wetland management in Chongming Island. Computer language as Visual Basic and component of MapObject 2.3 were used with database to develop six sub-systems (data management sub-system, index management sub-system, information inquiry sub-system, spatial analysis sub-system, comprehensive assessment sub-system and result display sub-system) of the whole system. Furthermore, in the support of decision-making support system of wetland ecosystem, users can easily manage and plan the prospect and development strategy of coastal wetland.Chapter seven is a conclusion of my research. The innovation points and ideas for improvement were listed for further research.To build a healthy ecosystem has become the main target of wetland management. Health assessment of wetland can help to prevent degenerative succession, furthermore, effectively manage wetland ecosystem toward sustainable development.