Study On The Spatial-temporal Change Characteristics And Influence Factors Of Urban Expansion In Tianjin

Since reform and opening up, China's productive forces has made great progress. Particularly in the eastern coastal region, with the adjustment of industrial structure and the acceleration of industry process, on the one hand, a large number of rural population pour into cities and towns, expanding the original urban scale; on the other hand, through the ways of changing county to city and changing township to town, a large number of cities and towns are newly set up. The population gathers to town, village turn into cities and towns and urban range expands constantly, we call the phenomenon as urbanization. Primary behavior of the urbanization is spatial expansion, which is the direct reflection of urbanization development.Through the analysis and research on the urban expansion; we can understand the essential of urbanization more deeply and offer effective space decision support for sustainable development of the city.On the basis of analyzing and summarizing domestic and international similar research, this papers regards extremely representative Tianjin as the research object and regards LandsatTM image in 1990 and 2000 and 2007 CBERS image data as the basic data, supported by geographical information system and remote sensing technology, extracting land use information in Tianjin,and then mainly studies and analyzes the spatial-temporal variation characteristic and the influence factors of spatial defference of urban expansion in Tianjin using GIS spatial analysis model and other methods.The main content of the thesis includes :(1)Afer preprocessing on the image,which includs band registeration ,geometric celibration,image enhangcing and so on, land use change remote sensing information is extracted firstly,the extraction accuracy is above 80%;then quantitative analysis on the change of land use types and the strcture of urban land occupies other land is carried on;(2)The analysis on the urban expansion rate and the relation between the urban land expansion rate and urban population increasing rate is performed,which separately use single land use dynamic degree model and urban land expansion flexibility coefficient ;(3)The spatial-temporal differentiation characristics of urban expansion is mainly studied. Regard every county of Tianjin as the minimum administrative unit at first, using urban land area and urban expansion intensity index ,the region difference and relevant influence factors of urban expansion is analyzed; then using quadrant position analysis , the position difference of urban expansion in main city zone and near regional town is studied; and then using buffer analysis method, the buffer around the city center is set up, the spatial behavioral characteristic of the urbanization course during different periods in Tianjin is analyzed;at last,the overall mode of urban expansion is comprehensive analyzed;(4)Combined GIS spatial analysis method, the influence factors of spatial difference of urban expansion is studied, the qualitative and quantitative analysis is carried on from respects such as population, transportation, economic development factor,etc. separately.