The Growth Of Cheng Yu Megaregion And Its Spatial Evolution

Megaregion has more comprehensive advantages over the single city, it is beneficial to become the central region.But,previous study are focused on the difference among megaregions,which ignores the gaps at different stages of growth and development about a megaregion.The urbanization is rapid at present in China,megaregion has an important strategic significance for the economic and social development in China.It is necessary to understand the evolution law of Megaregion,which can be avoided the blind development or improper development. This paper identified the basic concept on the basis of reviewing the domestic and foreign research results, then, problems is solved in the process of research, an analysis of quantitative and qualitative, using ArcGIS visualization technology, choose Chuan Yu region as an example, based on the long time scale, from non city to city, from non megaregion to the megaregion, make theory and case verifies.So as to further enrich the research achivement of megaregion.Specifically, the main process of growth can be divided into six stages, which are villages, market towns, towns, central city, metropolitan area and megaregion, and a number of megaregion constituting the megalopolis. Therefore, the definition of megaregion should be established on the basis of metropolitan area. Metropolitan area is the continuous region of mature urbanization, megaregion formed by multiple factors, such as population density, urbanization level, population size, degree of cultural identity, infrastructure, space continuity, connection of the administrative, polarization and diffusion. In addition, megaregion is different from the general urban system, which enjoys the closed relatationship and higer developed level.The case study shows that there is a cross process between separation and combination from ancient to modern times in Cheng Yu region. There is a long time separation between East Sichuan and Western Chongqing before Yuan dynasty, Chongqing city gradually catches up with Chengdu city at the times of Ming dynasty and Qing dynasty.During the Republic of China, withdraw the county and set up the city, that ended the pattern of city attached to the county since ancient times. At the beginning of the establishment of new Chinese, Chuan Yu region experienced a brief partition, then, got together. Chongqing city became a municipality directly under the central government in 1997, Chuan Yu region separated again. At present, the size of the population nearly the same between Chengdu city and Chongqing city, Chengdu City and Chongqing city are the poles of Chuan Yu urban system. But, the other cities which can be called intermediate level city are all collapse.Then, distinguished the difference between municipal district and city proper.On the basis, clarified the metropolitan area in Chuan Yu region. Central city and the periphery of the space range are growing no matter it is metropolitan area of Chengdu or the metropolitan area of Chongqing, and there is a trend of polarization for the two metropolitan areas. Considerated the possibility of growth and expansion for the megaregion, rather than the Cheng Yu megaregion.Cheng Yu megaregion formed at the end of the 90s of the 20th century, which main space body situated between the Chengdu metropolitan area and Chongqing metropolitan area. At the same time, it extended surrounding the metropolitan area. But, the core zone of megaregion is solid, which contains Chengdu, Ziyang, Neijiang, Deyang, Zigong, Meishan, Rongchang, Dazu, Yongchuan, Bishan and the city proper of Chongqing. There are three principal stages for the process of Cheng Yu megaregion, which can be listed as:rudiment, growth and space integration in the future. But, the urbanization of center cities tend to saturate about Chendu and Chongqing, the contribution of county urbanization is enhancing. Of course, spatial integration is benifical for the growth of Cheng Yu megaregion in the process of urbanization.The enterprises of foreign invest are becoming more and more prosperous with the development of economic globalization, which is useful to build world city for Chengdu and Chongqing, it is benifical to enhance the international level of Cheng Yu megaregion and promote Urbanization.According to equations of the relationship between urban population and non agriculture employment population, it indicates that there is a good interactive relationship. Certainly, absorbing Non agricultural employment population mainly depends on enterprise, Listed company is the backbone enterprises among enterprises. Generally speaking, the spatial network pattern of these listing Corporation is similar with the spatial pattern of the Cheng Yu megaregion. However, the flow of production factors and administrative authority are not integrated, as a result, these listing company tend to local investment in Chuan Yu region, witch is bound to affect the spatial megaregion of Cheng Yu megaregion and Chuan Yu region.Finally, the regional status of Cheng Yu megaregion is confirmed on the basis of national strategic planning, megaregion’s economic status, and center city’s strength. Generally speaking, Cheng Yu megaregion will grow into another new growth pole besides Yangtze River Delta megaregion, Pearl River Delta megaregion and Beijing Tianjin Hebei megaregion.