| Since the reform and opening, China has made great achievements in economic development. The household registration system and land use system in late 1980 s have speeded up the population in urban areas. The urbanization in China has improved quickly, which were regarded as one of the two biggest themes in the 21 st century. At the same time, large areas of cultivated land have been damaged by the deteriorating environment, water pollution and air pollution. China has nowadays deepen its reform and opening up policy, quality development has been the focus of all walks of life, and China has entered a new normal of steady economic growth. How to protect our environment while we developing our economy is the highest priority. Urban spatial expansion is the most outstanding feature of urbanization and also an important indicator of urbanization. Oasis city has the weaknesses of limited land area and fragile environment, so the improper spatial development will lead to serious environmental problems. This thesis takes Zhangye city, an oasis city in northwestern China with the arid and semi-arid climate, as an example, to study its urban spatial expansion, so as to provide a scientific development strategy for oasis city space.Taking urban planning as the research object, In accordance with the "characteristics, mechanism, prediction, governance" research train of thought, on the basis of carding the domestic and foreign studies, uses the multi-spectrum remote sensing image data and social economic data to analyze the spatial development, the spatial morphology and expansion and the land use in the process, with the help of Arcgis、Envi、Sleuth model、AI CS6 software and GIS spatial analysis, network analysis and so on. Then, at the basis of the comprehensive analysis of the spatial development of Zhangye city, the thesis analyzes the urban spatial dynamic mechanism, sets four situations to predict the spatial expansion of Zhangye city in 2020 and 2030 and puts forward the management strategies for the spatial development of Zhangye city which are all based on the SLEUTH model. The main structures of the thesis are as follows:(1)Spatial-temporal evolution study of the urban spatial expansion. Founded in the Xixia dynasty, Zhangye city has had a history of more than two thousand years. With Zhonggu Lou as its center, the city has four main streets which divide the city into such four parts. Within a half century, the area of the city has increased from 3.3km2 to 31.12km2 which has been made possible with various development rate from slow expansion to high speed expansion.Before 1990 s, the areas in its east, northeast and northwest have developed more quickly, while the other areas more slowly, which led to the moving of the city center to the northeast. After 1990 s, the areas in its south, southwest and southeast have developed slowly, while the other areas more quickly, which led to the moving of the center to northwest. With the analysis of the old city areas, the spatial distribution of the area 7km away from the old city areas is the smallest and the spatial distribution of the areas 14-17 km away from them is increasing. Overall, before 1980 s, the expansion was from the first and the second circles to the fifth and the sixth circles. After 1980 s, the expansion was from the inner circles to the outer circles. With the further study, the expansion of the city has experienced six phases, such as sporadic type slowly extended stage-sporadic type low speed expansion stage-spread type low speed expansion stage-enclave medium speed extension stage-spread type rapid expansion phase-group high speed expansion stage.(2)Urban spatial morphology model analysis. The spatial morphology model is becoming more and more complicated in the city. The boundary of the city is becoming increasingly irregular and compactness is becoming smaller. Three models of “salutatory”, “filling pattern”, “epitaxy” have co-existed in the process. From 1982 to 2000, epitaxy is the main expansion form, from 2000 to 2006, filling pattern is the main expansion form, and from 2006 to 2014, salutatory and epitaxy are the main expansion form.(3)The land change study during the expansion process. The land expansion occupies the cultivated lands and the grass lands and forest land which are all of great use, sandy land and bare land unused gradually be developed for the urban construction land. The residential land and public facilities have accounted for more land areas, while the Industrial and storage sites have been reduced. The residential land and public facilities dispersed from the old city areas to the edge of the city, which is the “prompter” for the spatial expansion of the city. While the Industrial and storage sites are mainly to the park central distribution, form the new "growth pole", which is the "drive" for the spatial expansion of the Zhangye city.(4)The factors and motivation system of the urban spatial expansion. Natural geography, transportation, social and economic development, urban development are the four main factors of the spatial expansion of the city. The geography is the basis of the overall pattern of the city, water resource and transportation are the factors of the expansion as well. The increase of the population in the city is the direct motivation and the fast development of the economy is the main prompter. The regional development policy, the city panning and the administration plan are the compasses of the spatial development. The social and economic driving force, traffic traction, natural environment constraining force and the government regulation force are the dynamic system of four formation cycle, and the different stages of the main driving force.(5)Urban spatial expansion cellular automata SLEUTH model. The future development of the city takes the environment protection as its priority. Its focuses on developing a city of compactness and adjusting its city planning. The wetland nature reserve, lakes and so on are to be protected by forbiddening city to expand in the north. The cultivated land areas are to be preserved by restricting to expand in the east and south. Explore the unused development development model, guide the city across the river to the development to the west. And actively revitalize the stock of existing urban land, improving the efficiency of economical and intensive use of urban land. The formation of the "east limit, west enter, south control, north ban, internal dig" urban land development direction.(6)The management policy study of the urban spatial expansion. With the expansion of the city, the cultivated land areas are becoming less and less, the distribution of the urban area is uneven and the environment of the city are deteriorating. A more proper system for the expansion should be put forward to optimize the spatial distribution of the city, improve the usage of the land, develop the usage of the land within the city to promote the compactness of the city and encourage the pattern change of the environmental protection, to make the city more comfortable to live in and to provide evidence to the city development of the oasis cities in arid areas in China. |
PDF Full Text Request