摘要
Globalization and rapid urbanization have become a hot issue in the contemporary urban development process. City resources’ over-concentration and the environmental problems bring new pressure to urban infrastructure. So the study of green infrastructure planning under the background of eco-city is imminent. From the medium scale of green community, the ecological infrastructure planning is the way of constructing urban ecological grid and its scope of application most focus on metropolis, cities and towns. Compared to large scale, it will has more research significance as its ecological infrastructure carrier distribution is more scattered and random causing from the urban land's fragmentation. The paper studies the multi-functional connotation and four planning principles of ecological infrastructure through the research methods of data collection, case analysis and field research starting from the medium scale of city. The ecological infrastructure planning of green block scale is multi-function and multi-dimensional. In the process of green infrastructure planning, it should be based on the planning principles of multi-disciplinary, multi-level, integrity and sustainability. Finally the article based on the example of Philadelphia ecological storm water infrastructure planning successfully build and implement a Philadelphia's green stormwater infrastructure grid and improve the ecological outlook through the measure of the combination of different groups in the city, the incentive policy guidance, the multidisciplinary planning system and putting forward the concept of measuring quantify of ecological infrastructure - “Greened Acre”. Ecological infrastructure planning method is no longer constrained by the ecological protection but tend to be more functional and multi-dimensional in order to solving complex problems in city.