Urban Land Use Growth And The Spatial Coupling Based On Gravity Model

Urbanization is a hot issue in our country. In2000, Stiglitse, who Won the Nobel Prize in economics, once said:two things will exert an profound influence on human society process in the21st century, the first is the new technology revolution which is leaded by US, the second is the China’s urbanization. Under the macro background of rapidly urbanization in China, the land use also faces a revolution. the blind expansion of the city not only caused the disruption of land use, the low utilization efficiency of the land resource, also put huge pressure on the protection of the ecological environment and the protection of the cultivated land resource. Scientific urbanization direction and policy will be to achieve the optimal allocation of land resources, and the protection of cultivated land resources. So it is significance and valuable to do the research on urbanization in China. More and more urbanization researcher divert their attention from qualitative research to quantitative research. Gravity model is an important tool for quantitative analysis of the space interaction. It will have broad prospects to apply the gravity model to the quantitative study of urbanization.Tongshan counties in Xuzhou which is a typical suburban district is the research area of this paper. This paper firstly construct the gravity model and the formula of the breaking point.. Secondly, calculate the gravity and gravity breaking point of different towns based on the gravity model and the support of GIS. Thirdly, divide the research area according to the different characteristics of different towns. Fourthly, analyse the coupling relationship between the gravity and the newly-added construction land of the typical town in different subarea. At last,put forward differentiation direction and the suggestion of urban land development and the protection of land resources to different towns. The main conclusions of the study include the following:(1) improved the gravity model with more influencing factor including the construction land scale, development potential and the correction factor of the city level. Put forward the double-gravity hypothesis:the research area are under the influence of two gravity source: Xuzhou city and Tongshan counties.(2) Divide Tongshan into four zones called "double-gravity zone","Xuzhou-Single-gravity zone","Tongshan-single-gravity zone"and "weak-gravity zone","double-gravity zone" is composed of Tongshan Town and Zhangji Town;" Xuzhou-Single-gravity zone" is composed of Liuxin Town, FangcunTown, Yizhuang Town, Shanji Town, Xuzhuang Town, Daxu Town, Maocun Town, Liuquan Town, Liguo Town;"Tongshan-single-gravity zone" is composed of Dapeng Town, Hanwang Town, Sanpu Town,Tangzhang Town;"weak-gravity zone" is composed of Heqiao Town, Huangji Town, Mapo Town,Liuji Town, Zhengji Town.(3) In "double-gravity zone" and "weak-gravity zone", it show a stong coupling on the gravity and the distribution of the newly-added construction land. In "Tongshan-single-gravity zone", it show a general coupling on the gravity and the distribution of the newly-added construction land. In "Xuzhou-Single-gravity zone", it show no coupling on the gravity and the distribution of the newly-added construction land. The distribution of the newly-added construction land is unordered and do not follow the gravity rule..(4) According to the results of the gravity partition and the proving of the coupling relationship, put forward differentiation direction and the suggestion of urban land development and the protection of land resources to different towns:designate "double-gravity zone" as development and construction zone; designate "Xuzhou-Single-gravity zone" as longitudinal development zone and optimal protection zone of the cultivated land resource; designate "Tongshan-single-gravity zone" as horizontal development zone and optimal protection zone of the cultivated land resource; designate "weak-gravity zone" as the main protection zone of the cultivated land resource. Each of the4zones is set different land use direction and land use regulation to achieve optimizing of land-use spatial allocation.