Study On The Urban Agglomeration's Spatial Organization Oriented By Inter-city Transportation

In the process of urbanization, a remarkable phenomenon is the emergence of urban agglomeration. When the city size and economy develop to a certain degree, the non-agricultural industries gathered in urban area and the other city functions will spread around the city, or the material exchange among cities have become increasingly close to each other, thus the cities (towns) in certain region maintain close social and economic communication, and form the integration of city function areas, which is called urban agglomeration, that share the resources, environment, and infrastructure, with close industrial economic relationship. The emergence of urban agglomeration not only caused the reorganization and change of city geographic space form and scale, but also formed a new flow and distribution capital, industry, labor and otherfactors. Urban agglomeration's spatial organization is also the space distribution and movement of the material elements (space relationship among all material elements) and the activity elements (spatialdistribution of economic, social, cultural activities) in the space of urbanagglomeration.Study abroad on the theory of urban agglomeration's spatial organization can be traced back to E. Hoard's Garden City Theory and the subsequent discussion on the construction of satellite city and new city. Latterly, P.Geddes and L.Munford actively promoted the research on urban and regional development, and recommended to study the urban space issues from the broader area outside of the city. P.Hall, J.Friedman and P.J. Knox explored the characteristics, functions, structure and grading system of big cities all over the world from an aspect of world cities, globalization, and the information technology networks. Since 1980s of the 20th century, Chinese scholars also started research on the spatial organization in big cities. Research focused on the development of big cities under the background of globalization, such aspopulation migration, suburbanization and urbanization in the suburbs;internationalization of Chinese cities or spatial development ofinternational cities; the export-oriented economy of urban agglomeration, . New industrial are and the impact of investment on urban spatial structure.Urban geography, urban economics, economic geography and sociology have contributed more or less to the research on urban spatial organization. Theoretically speaking, the urban geography focus on the three major elements: scale, function and space, and the infrastructurenetwork as well, but the new urban spatial pattern - urban agglomerationhas not been fully studied. Urban economics focus on urban industrial development, industrial restructuring and urban economic developmentstrategies, whereas little study has been done on the spatial distribution of urban economic activities. Economic geography covered certain studies on the combination and spread of economic activities, and theformation of new industrial areas, however, less study is available on the combination between industry distribution and urban spatialorganization. City planning is mostly focused on city space planning, design and integration, and less theoretical study is available on the urban spatial evolution. Urban transportation include meticulous research on the comprehensive urban transportation planning, some researchers are beginning to study the transportation in urban agglomeration, nevertheless, a further understanding is required on the interaction mechanism between urban agglomeration space and inter city transportation.Multi-center structure is a relatively common style and apparently superior to the single nuclear development style as far as the spatial distribution of urban agglomeration is concerned. In western countries, the formation of multi-center urban agglomeration is mainly caused by suburbanization, including the formation of sub-centers (satellite city, new city) and edge city, and formation of multi-center distribution.Although many Chinese and foreign scholars have noted theulti-center distribution has both strong core multi-center group and weak core multi-center group, the study on evolution pattern andhanism of urban agglomeration space has been mainly focused on the evolution from single-center to multi-center. Obviously, urbanagglomerations in China such as the urban agglomeration in Shandong Peninsula urban agglomeration and Changzhutan urban agglomeration have developed following a multi-center collaboration and coexist, co-developing path with respect of the evolution pattern and mechanism.The choice of development path is fundamentally different from that for a single-center model. Considering that with the promotion of economic globalization and regional integration, economic activities are not confined to be inside the urban agglomeration, the international and inter-cluster 'city flow' is not only able to promote the self development of urban agglomeration and spatial evolution, but also can further promote the 'interaction' among urban agglomerations and create a larger scale urban agglomeration, as the megalopolis. The author namethe above three development models of urban agglomeration as: single nuclear fission type, polynuclear symbiotic type and network open spatial organization.As far as the dynamic mechanism of urban agglomeration space evolution is concerned, researchers have conducted theoretical and empirical studies from the aspect of suburbanization, migration, construction of new industrial area and the influx of foreign capital according to the formation and development of various cities. There aretwo limitations of these studies: First, the evolution of urban space is a result of the comprehensive economic and social activities. Therefore, itis a full scale study if only one or two of the factors labor, capital or technology were considered to study the urban space dynamics.econdly, as the urban agglomeration is geographical space consist ofdifferent urban systems, it is biased to study the urban agglomeration space movement from city to city or from inside of the city. The author believes that the evolution of urban agglomeration space is driven by three forces: the first is the combined effect of scale, scope and integration economies from inside cities, has made the labor, capital, technology and other material elements as driving force for the evolution of urban agglomeration space movement. The second is from outside of the cities. The inter-city economic communication causes the flow andand re-distribution of material elements among cities, which is 'projected' on urban regions as different distribution patterns of urban agglomeration; Third is the regulating forces from governments and society. City planning, road construction and other acts of the government, together with the regulation of labor and cash flow by social organizations, have played an important role in the formation of urban agglomeration. The driving force, attraction, and regulating force constitute the dynamical system of the evolution of urban agglomeration space.Transportation, in particular the inter-city transportation plays a unique role in the evolution of urban agglomeration space. Transportation orients the direction of the development of urban space, constitutes the city's spatial development framework. Urban spatial structure appears the asteroid, stretching and other irregular shapes. Transportation development has lowered unit costs of transportation and promoted the spreading of urban economic activities and forming new gathering point in the area of certain regional advantages, and the formation of multi centers. Transportation has contributed the economic communications among cities and towns, and promoted the specialization and evolution of urban division and function. It also drives the development of each center city and the flow and combination of elements among cities. The driving force, attraction force and regulating force have promoted the evolution of urban agglomeration space throughthe transportation network. In addition, the economic development ofurban agglomeration, the size expansion have also raised the requirement for inter-city transportation. Choosing an appropriate mode of transportation is of great significance to promote economic development and urban spatial structure optimization. Following the classical regional theory, the new economic geography and new classicaleconomics, and based on the research by An hu sen, the author has developed models and drawn two important conclusions: 1. The concentric expansion of single center city space results from the market mechanism and wont stop unless there is integration non-economic effect. In light of China's reality, with the rapid urbanization, urban central development, to overcome the disadvantages of spreading development type, it is necessary to increase transportation efficiency and build reasonable, close related multi-center distribution by developing inter-city transportation, and dredging the interaction between center city and satellite city. 2. With the improvement of theransportation efficiency, the uniform distribution has been broken among cities that are geographically close to each other but originally in the independent development. The attraction among cities has been markedly increased, uniform effect appears and urban agglomeration is formed. Cities become increasingly close to each other, and the urban spatial structure reveals a multi-center network-like structure. Considering the planned urban agglomerations in china are facially similar but essentially different, To promote the substantial integration of cities by developing inter-city transportation is of great significance for the development of urban agglomerations, consequently provides a theoretical foundation for the urban agglomeration's spatial organization oriented by inter-city transportation.There are many forms of urban agglomeration transportation, road, railway, aviation and shipping constitutes a complex, network-like urban agglomeration transportation system. Different modes of transportation are needed to guide different spatial organization pattern of the urban agglomeration. The author has studied the formation process of urban agglomerations abroad and the spatial development of domestic cities, and made two conclusions: 1. For the nuclear fission type of single-city development, the key is to resolve the transportation requirement of a large population to live in the center city and work in the satellite city or vise versa. Urban mass transit (UMT) makes the multi-center possible because of its high speed, large capacity, and long distance between stations. It also helps avoid the random spreading of cities along the traffic lines resulted from road transportation. 2. For polynuclear symbiotic urban agglomeration, as urban commuting distance is often longer than 50 kilometers, and the major element flow is material flow, population flow can not exceed lower limit of UMT, therefore UMT is not economic, whereas the construction of highway is a more reasonable choice. In addition, for the trans-international, inter-city transportation urban agglomerations, because of the long distance and geographical obstacles, aviation an shipping can meet the transportation requirement of network like, open urban agglomerations. In this work,the function mechanism of transportation on urban agglomeration's spatial organization was investigated; a creative and systematic analysis was performed on the nuclear fission-urban agglomeration's spatial organization based on UMT, the polynuclear symbiotic -urban agglomeration's spatial organization based on highway transportation and the network like, open urban agglomeration's spatial organization based on aviation and shipping. Using the Paris metropolitan area, Guangzhou, Shenzhen and Hong Kong and other cities as examples, an empirical analysis was performed on different inter-city transportation modes and urban agglomeration's spatial organization. Finally, empirical study was conducted on the spatial optimization of Jinan city and on the Mid-Shandong urban agglomeration's spatial organization centered at Jinan.In summary, this work includes a progressive and systematic study from the inter-city transportation promoting the development of urban agglomeration, namely, the theoretical basis, to the three models for the evolution of urban agglomeration space, the to the dynamic mechanism of urban agglomeration development and the function mechanism of inter-city transportation to the evolution of urban agglomeration space,and finally to the urban agglomeration's spatial organization oriented by different modes of transportation. This research is important as a reference for the study of urban agglomeration's spatial organization and the mode selection of transportation in urban agglomeration.