Study On The Evolution Of Dual-nuclei Cities’Urban Spatial Organization

The global is experience tremendous economic and social transformation, various forces in the city can develop, combine and change during the period that will have a great impact on urban governance mode and space reconstruction of urbanization. New motive forces of industry development, new consumption demand, new function transformation, new diversified investment mechanism and people-oriented and sustainable development conception result in new changes of urban space, new urban space occurs, urban problems tend to show as the "mixture" of centralization and decentralization, over centralized old centres need to be spreaded, and the new formed center need to be centralized, the degree of "centralization and decentralization" always affects the development of the old centers, as well as the new ones.Because of the high carbonization of urban spatial structure in China, dual-nuclei cities start to appear, it means in the historical development of a city, because of a special factor, another important urban built-up area is gradually formed in a certain distance from the main city, the new nuclei has similar scale with the framework of the main city, it also functions similarly to the main city, and gradually affects direction and focus of the overall urban development, urban space organization will be more and more optimal because of new constraints and driving factors.In order to study the double-cored phenomenon deeply and clearly, we will discuss the problem in the aspects of conception, morphology development and dynamic mechanism, space efficiency, succession trend, we also built the theoretical research framework of the spatial organization succession of double-cored cities, by studying many double-cored cities, such as Tianshui、Nanping、Benxi、 Suzhou、Guilin、、Lianyungang、Yixing、Bazhou、and some other small towns where dual-nuclei culture occurred, we collected materials of unban continuous development mechanism, use historical tracks to support my study, finally I will present three kinds of recent urban dual-nuclei development mode, offer substantial help to the government to plan and guide dual-nuclei urban space development, finally I carried out a systematic theoretical analysis future plan on Bazhou dual-nuclei city. This chapter is organized as follows:The first chapter is about new trends of China urban space organization. Analyze the background of the existence of dual-nuclei cities and overview of the urban space organization, summarize previous basic understanding of dual-nuclei morphology, find out the defects of existing theories, determine study methods and direction.The second chapter is about the "core" of dual-nuclei cities. I will summarize the conception of dual-nuclei city with dynamic ideas, analyze core problems of "the old core" and "the new core", and classify dual-nuclei cities according to different induce factors.The third chapter is about the space organization morphology and dynamic mechanism of dual-nuclei cities. Study on the space organization process of constraint type and condition driven dual-nuclei cities respectively, including characteristics of morphology development、succession factors and the dynamic mechanism.The fourth chapter is about space efficiency of the overall urban system. It will study that in the aspect of function efficiency (the respective function organization of the two cores)、economic efficiency(the overall economy of space organization)、environmental efficiency (the ecosystem of regional angle)The fifth chapter is about succession trends and space organization integration. Present the mode of maintaining the independent development of the two cores、double cores linkage ribbon development、 the main city-satellite town development, analyze the condition for development、development mode and advantage and disadvantage of each mod。The sixth chapter is the empirical part. Analyze the background、morphological characteristics、 dynamic mechanism、space efficiency of the dual-nuclei city in Bazhou, learn from the building mode of the new city Marne La Walai in Paris, deduce the future development and mode of cities in Bazhou.Chapter seven is conclusion and prospect.