Research On Urban Space Development Of Metropolises

With the high-speed development of global economics, the urbanization and sustainable development of cities become worldwide hot issue. Urban space, whose reasonable form would influence the living quality of human beings, is the carrier of all sorts of functions in cities. During the rapid urban expansion on a global scale, the urban spatial form changed dramatically and many sharp problems such as improper land use, loss of arable land, serious destruction of ecological environment, heavy pollution, imbalance of urban function layout and so on. Since the urban spatial development is a dynamic process and each stage has its own characteristics, those research results which we already had may explain and answer those problems decades ago, however, they may not explain those new phenomena and problems which emerged recently in urban spatial forms. The research on urban development stages could not only provide addenda to the old urban spatial form theory system, but also be advantage to guide the complication and implementation of urban planning. On the other hand, for the urban spatial development is a complex process with many factors interacted on each other,combing the influence factors in each stage would be helpful to urderstand the dynamical mechanism behind the urban spatial development and to lead the future development of cities to a healthy direction. Chengdu, as an important metropolis in southwest of China, has typical binary structure of urban and rural areas and also has the ring-layer-spread problems which are representative and valuable. The construction of Tian Fu New Area began in 2011 means that Chengdu has entered a double-center era which changed dramatically the traditional single-center centralized structure of Chengdu. The future development of Chengdu metropolitan space needs further exploration. In this context, the dissertation studied 3 American metropolises and Chengdu, used GIS and Cenllular Automata techniques to undertake the researches on urban spatial developming stages, developing pattern, influence factors and dynamic model of metropolises.During the studying in United States, the author collected a large sum of data, pictures, literature information about typical metropolises in western, midland and eastern part of United States by literature reading, field investigation and deep interview, analysized and processed those data and materials by statistics and mathematical analysis,and finally arranged and explored the urban space developing stages and influence factors in urban growth of different American metropolises in different areas. Both Chicago in the midland and New York in the east were grown from traditional industrial age with a single-center centralized spatial structure and ring-layered sprawl pattern before. On the contrary, Los Angeles, the new metropolis of western Sun Belt, kept the low-density, centerless, flat and distributed spatial pattern from its birth on. Chengdu metropolis was chose as the domestic case for depth exploration. From city planning departments and relative government departments, a mass of pictures, data, literature materials were gathered and analysized on the characteristics in different developing stages and structure of urban space development in Chengdu in many aspects such as general situation, spatial characteristics, developing history and expansion stages, future planning and Tian Fu New Area construction. On this basis the dissertation integrated the developing stages and influence factors of Chengdu metropolis and 3 American metropolises analyzed above, summarized 7 impact factors(IF) which were nature, economy,population, land ues, traffic and communication, planning and policy, society and culture, and analyzed the effects those impact factors affect on the urban space in different stages. The research results could be used as references by relative goverment departments when planning.The urban spatial form evolution is a typical dynamic complex system with a open,self-organizing, dynamic and non-balanced structure and would be influenced by many factors such as politics, economy, society, nature, policy and so on. The evolution of urban spatial form has strong dynamics and complicacy. The macroscopical and static urban model in the history could not meet the needs of current research, so the research on urban spatical evolution dynamic model became the efficient measure and hotspots in urban spatial evolution. Cellular automata, or CA for short, is a grid dynamical model which could calculate from buttom up and from parts to the whole. The urban developing dynamical model based on CA theory has been the hotspot of geographical information research fields. Most researches of CA urban models focused on the geographical information of urban land use, so this dissertation, from a perspective of urban planning, added the natural, economical, social, cultural factors into the urban spatial dimension, used Avenue as a secondary development language to build Multi-factor CA model based on ArcGIS plarform, determined parameters of the MFCA model and designed the optional transformation rules for MFCA. This model, MFCA, could be used to evaluate the historical developing process of urban space and simulate the future development and is the beneficial supplement of current urban cellular dynamical model system.For the urban spatial developing planning of Chengdu, the historical data were used to adjust the parameters in MFCA model and compared the simulating results with the reality of urban space status of Chengdu in 1980,1994 and 2013, which confirmed the usability and reliability of MFCA. On this basis, the future development of Chengdu metropolitan spatial form was simulated and several advice was put forward for its future spatial development, which could be taken by relative government departments for reference.