Study On Urban Green Space System Planning Based On Generative Mechanism Of Spatial Form Of Green Space

The urbanization process was developing rapidly in China. It entered a new urbanization stage now, which demanded a transition form size expansion to quality promoting. Urbanization made the urban system complicated. It resulted in complicated in internal elements and structure of the green space system, and more closely in the relationship with the external environment. All of this put forward new requirements for urban green space system planning.Green space system was an open system. In addition to the interaction of internal factors, there were interaction and mutual restriction between the system and the external environment. Comparative study method was used to analysis the existing problems in the planning of urban green space system and extract the factors affecting the urban green space generation. Deductive reasoning method was used to treat the reality and the developing law and trend in the future dialectically, to analyze the relationship among elements of green space system, as well as the relationship between layout structure and function of green space, to explore the developing process and generation rules of the spatial form of green space system, to clarify the generative mechanism of the spatial form of green space system. The synergistic theory was applied to the green space system planning to discuss the synergistic layout principle and the planning method of urban green space system based on the generative mechanism of the spatial form of the green space. Through the practice test, the scientificalness of the synergistic planning method was proved, and its problems could be found to promote the research work to deepen and perfect.Research contents and results were reflected in the following4aspects:1. Factors of the urban green space generation were summed up.According to the principles of significance, comprehensiveness and systematic, the main factors selected from multitudinous factors which affect the urban green space generation. They were divided into3categories:basic factors, endogenous driving force and exogenous guiding force. The basic factors including the natural resources and human resources conformed the framework of urban green space. Endogenous driving force included recreational function requirements, disaster prevention requirements, landscape requirements and ecological requirements. They were motive power of the green space generation. Exogenous guiding force included the social environment and economic environment. They guided the developing direction of green space.2. The generative mechanism of the spatial form of the urban green space was revealed.It is pointed out that the development of urban green space system was a composite process of self-organization and hetero-organization. In the generative process of the spatial form, through self-organization mechanism in its own laws, and by artificial control, green space system improved continuously by the outside direct intervention. Its mechanism was consists of3aspects. First, appropriated mechanisms complying with land characteristics. The distribution of green space is influenced by natural resources and cultural resources. It can protect the resources. Second, the self-organization mechanism restricted by functional mechanism. In the restriction of recreation, disaster prevention, ecology and landscape functional mechanism, and followed the principle of coordination function, spatial form of green space was self-organized and the structure became more orderly. Third, external regulation mechanism. The social and economic environments were the exogenous guide force to the generation of the spatial form of green space, controlling and guiding the green space generation. Generative mechanism of green space revealed in this research belonged to a blank-filling work in some extent. It was of scientific guidance meaning to urban green space planning.3. A pattern of functional synergy of the urban green space system was established.Based on the functional synergistic mechanism in recreation, disaster prevention, ecological and landscape etc. of the green space and taking multifunctional coordination as the goal, a networking layout pattern of green space system was point out which could exert all functions of urban green space. This model make green space service range to cover the whole city, and make area park to be located in the green belt. A good structure is formed. The green space can also effectively avoid disaster, play ecological and landscape function of green space.4. A method of synergistic planning of green space system coordinating in several aspects was established.By using the system theory to introduce the synergistic viewpoint, on the basis of the generative mechanism of the spatial form of green space, theory and method of the green space system planning were pointed out, which was guided by mechanism, coordinated in internal function and with external environment. It was an innovative attempt. Based on docking with current outline of green space system planning, the function system of green space was decomposed into a classification system of green space that is the current national standard, so as to make the synergistic planning method of urban green space system operable.