The Characteristics Of Multi-functional Landscape And The Response Of The Water Enviroment Of The Wetland In Ubanization Area

Urban wetland is one of the very important urban ecosystem and landscape, which can sustain the urban multi-functional landscape.However, the urbanization developed quickly, and the wetland ecosystem environment was suffered the practical or potential threats. How to follow the process of urbanization and to reveal the characters of landscape multi-function is very important to research the relationship between the urbanization and the urban wetland. Several discipline theories and methods,which including the theories of geography, landscape ecology, environmental science and the methods of RS, GISet al,were used to study the theory of the urban wetland and the multi-functional landscape in the new city of Xianlin, Nanjing. The main research findings include:(1) Based on the conception and connotation of urban multi-functional landscape, the diversity and heterogeneity of landscape in the New city of Xianlin were explained. The results showed that the landscape structure changed significantly, and the mutli-functional landscape had shaped.We had also regionalized the area into four units, social functional area (21.4%), social-aesthetic functional area (13.9%), aesthetic-ecologic-social functional area, productive-social functional area (41.5%).(2) Based on the wetland ecosystem, catchment and landscape functional area, Urban wetlandmulti-scaleClassification system was establishedto reveal the relationship between urbanization and water quality. First of all, the wetlands were divided into2main class, and3subclass, and8small class.(3) The basic characteristic of urban wetland showed that the water level and water quality waved significantly in different seasons, and the water quality heterogeneity varied among different wetland. The water quality in a disordered status in Urban controlled wetland, while the water quality would be worse when the the human effect index got bigger in Rural controlled wetland. However, the water quality was better in the Urban controlled wetland than that in Rural controlled wetland. Both of the two type wetland water level got changed significantly when the human effect index got big at some extent.(4) Urban wetland water quality was defferent at varied scales. The wetland shape and plant types were the main fators which influenced the water quality at ecosystem scale. At catchment scale, there was a threshold between water qultity and HEI. Wetland water quality would be getting worse while the value of HEI reached1.2. The water quality was not good in the productive-social functional areas, because they were suffered from the urbanization and agricultural activity.(5) The coupling results at different scales were analysed. The results showed that, there was a well connected relationship between them at the ecosystem sacle and catchment scales, and their explanation contribution were14.4%,31.4%respectively. There was a very significantly resistance between water quality and urbanization at the high HEIareas at the catchment scale.(6) Suggestions were given at wetland ecosystem scale, catchment scale and the landscape scale on the background of the multi-scale characteristics of urband wetland. Decreasing the impact of the wetland shape and the plants, and optimizing the different land use and the landscape functional area would improve the wetland water quality to realize the urban development and ecosystem environment be harmony and unified.