Regional Center City Formation & Developing & Planning Strategy Research Basing On Flow-Space Theory

When we doing research in Pearl River Delta and Yangtze River Delta about city level changing, we find that there are several paradoxes for using traditional location theory which based on site space to explain the reason why center cities grow and develop. In this case, we try to use flow space theory to find out the cause of center cities developing instead of site space theory, indeed, it will make some contributions to building a multiple center area which not only has convenient traffic, but also appropriate city-function. Therefore, we make a model to calculate the flow of the center cities with the methodology of GIS and Principal Component Analysis, besides, we using Hancheng, Shaanxi as an example to prove the hypotheses that we proposed.As the conclusion, we find that the reason why center cities are developing is related with the flow strength, species and efficiency in the area.First, stronger flow make the number of center cities increase. Second, more type of flow make cities more functional which means higher city level in area. Third, efficient cities is more competitive than other cities, and that will lead the cities become center cities.For making center cities better, we need to plan in a more scientific way. Firstly, the plans should be made in a comprehensive method. Secondly, the plans making should base on the problem that the cities have. Thirdly, the planners should distinguish the differences between site space and flow space, so that they can choose the correct theory in planning practice.