Comparison Of Remotely Sensed Monitoring,Urbanization Effects And Driving Factors On Urban Expansion Among The Eastern, Central And Western In China

City is originated from human labor division and cooperation. It not only is the product of social division of labor development at a certain stage, and is the crystallization of economic development and social civilization, but also is place with a variety of contradictions collection. Along with the industrialization, city expands rapidly. Although the city’s development has brought the material and cultural prosperity, but also has made some problems, such as consumption of good arable land, environmental pollution, traffic jam.Therefore, the expansion of the city has attracted widespread attention from scholars at home and abroad.Since China is a long-term farming country, it has not attached importance to the development of the city, resulting in the lag development of city. Recently, China is under the rapid urbanization, and urban built-up area expands rapidly, so that the environmental and social problems are particularly prominent. In addition, China has a vast territory, there are greater differences among different regions due to the policy, geographical location and other reasons. Therefore, the comparison of eastern, central and western on urban expansion is very important in China. It provide a reference not only for the decision-making of urban development and land management but also for government scientific guidance to the urban development of eastern, central and western at the macro level, thereby, to coordinate regional developments, and to effectively advance the process of China’s urbanization.This study selected Hangzhou, Hefei and Guiyang as representatives of eastern, central and western cities in China. The main line of space is along the east to the central to the west. The use of remote sensing and GIS technology extract the relevant information about these cities. Combined with statistical data and specific national conditions, this dissertation took urban expansion process monitoring, driving force and expansion effects as a main logic line to compare the expansion features of the urban built-up areas, and to analyse the driving forces and urbanization effects of urban expansion in the study area. Based on the above research achievements, this dissertation put forward some constructive suggestions on land resources management and urban development in China.The main results of this study are as follows:1) The information of the urban built-up areas, the spatial distribution and the change of expansion was obtained by remote sensing images interpreting in this study, and the same indicators for quantitatively measuring the city expansion were used for all the representative cities to make quantitative comparison of expansion process temporally and spatially.The results show that there are differences of the expansion of built-up area in rate and extent in space.First, from the view of the average annual rate of built-up areas expansion, each of three periods has different degrees of increase:minimum, gradually accelerate, and maximum (2005to2009). The expansion of urban built-up area differed obviously in space. Overall, the expansion rate for eastern region is fastest, followed by the central and the west regions. The eastern urban built-up area of Hangzhou City show the three stage characteristics of rapid expansion, high expansion, and high expansion. The three stage expansion characteristics of central Hefei City are moderate expansion, rapid expansion and high expansion. For the Western Guiyang City, the three stage expansion characteristics are slow expansion, moderate expansion and rapid expansion.Second, from the view of urban expansion elasticity coefficient and construction land area per capita, In the three study periods, the pace of the built-up area expansion adapt urbanization for Hangzhou city; during the first two periods, the pace of the built-up area expansion adapt urbanization for Hefei city, but the urban built-up area expansion of in the third period (2005-2009) is obviously too fast for Hefei city; while the urban built-up area expansion of the first period (1993-2001) is obviously insufficient in Guiyang, and the pace of the built-up area expansion during later two periods adapt urbanization in Guiyang.Finally, from the view of land classification of the urban built-up area, green land and water of the urban built-up of east-central--western study area both experienced an increasing trend with the expansion of built-up areas. The green coverage rate increased significantly, but the proportion of water showed a downward trend. 2) This study analysed qualitatively the driving force of the urban built-up areas expansion from the perspective of social, economic and policy factors, and made the grey correlational degree analysis between urban built-up area expansion and the main social economic factors in east-central--western study area such as the non-agricultural population, the number of college students and the total industrial output value et al. The results showed that the driving force of Policy factors play a leading role in the three major factors because of China’s special national conditions, and the implementation of the policy determine the changes of the socio-economic factors. For driving force of urban built-up area expansion, non-agricultural population is maximum in five socio-economic factors, and the total investment in fixed assets is minimum, and the amount of higher education enrollment played an important role; For Hangzhou and Hefei, the driving forces for urban built-up area expansion are in the following order:Non-agricultural population> on-campus college students> industrial output value> GDP> the total investment in fixed assets; For Guiyang. the driving forces for urban built-up area expansion are in the following order:Non-agricultural population> industrial output value> GDP> on-campus college students> the total investment in fixed assets; The correlation degree between the five socio-economic drivers and the built-up area expansion is highest Hangzhou, followed by Hefei, and Guiyang.3) The quantitative analysis of the green coverage rate, the green area per capita and the urban-heat-island ratio index for showed that, from time of view, with the expansion of urban built-up area in the east, central and west of the study area, green area and the heat island area are gradually increasing, and is temporally and spatially consistent with the expansion of the city expansion. Green coverage and green area per capita increased constantly, particularly for the2005-2009period with a significant increase. The urban-heat-island ratio index showed a downward trend, and the area of thermal field variability index≥0.010(poor ecological environment) proportion of total built-up area was reduced, with occurring zone scattered around city from relatively concentrated in the city center, reflecting the increasing emphasis on the improvement of the ecological environment and the rational distribution of green space in the process of city building as a whole, and cities are developed towards ecology trend. From region of view, the fastest increase of green coverage rate, the green area per capita occurred in Hangzhou in eastern region, followed by Hefei city in central region and Guiyang city in western region, reflecting the greening development in Hangzhou and Hefei are better than that in Guiyang. All these results indicate that urban expansion not only did not cause the decrese of ecological environment but also made the ecological environment better than before with the speeding up of the construction of built-up area.In summary, this study think land control policy should not always be homogenously strict, and spatial differences of land control might be supplied. Appropriate land supply is necessary to the guarantee of urban development and improvement of the city’s ecological environment, which is an initiative adaption to the urbanization. The eastern region need vigorously develop the Metropolitan Interlocking Region. The government should focus on solving the problem of employment of graduates from college enrollment via the technical and capital intensive enterprises; the central region should selectively develop Metropolitan Interlocking Region, substantially developing the large and medium-sized cities; western region should selectively develop the large medium-sized cities, and put more effort to develop small and medium-sized city. That is because the central and western regions should focus on solving the urgent problem of employment of a large number of low labor skill labors, probably via the labor-intensive industries.