Research Of Urbanization Level In Southwestern China Based On DMSP/OLS Night-Time Light Intensity Data

Because of the policies of reformation and opening, China’s urbanization process is accelerating, and now in the rapid development stage of urbanization. How to provide the relevant information in time to the urban development, the urbanization problem, and the research of the influence of the urbanization development on the ecological environment become the hot issue of urban development research, which receive extensive attention of the society.This study selected Southwestern China as the study area,1993-2013 as the study period, social-economic statistical data and DMSP/OLS nigth-time non-radiometric calibration light intensity data has been used to extract the information of urbanization through setting the threshold in every city. Then the GIS spatial analysis methods and Remote Sensing image analysis has been used to research the urbanization and its driving mechanism. Because the process of urbanization in Chongqing and Kunming is accelerating, so this thesis extract the information of urbanization in Chongqing and Kunming for analysis and research while reserching urbanization information in Southwestern China.In thesis, DMSP/OLS night-time average light intensity images has been used to construct the compounded night light index which can reflect comprehensive urbanization level of every city in Southwestern China and to analyze their spatial and temporal variation characteristics. CNLI found the practical and operational method to evaluate the comprehensive situation of urbanization process through the modern method, which can weaken such defects on the feasibility and accuracy in traditional method. Relativity analysis between the index of urbanization level and CNLI showed that the method we used was scientific and feasible.In thesis, we extracted spatial information to bulid the operation program, the DMSP/OLS light data model has been used to estimate the overall level of urbanization in the region, the research work has been followed:(1) 1993-2013, the area of Southwestern China and the number of patches continued to increase, Patch Density decreased first then increased, but decreased overall. City in the overall trend to decrease fragmentation and it will reduce and then increase in a certain period. All the above information reflects lower degree of discrete southwest of the city.(2) Among the cities of Southwestern China, Chongqing had the highest level of urbanization, Kunming, Sichuan were followed, relatively Yunnan, Guizhou, Xizang has low level of urbanization.(3) Southwestern China had got an acceleration of urbanization in cities and counties form 1993 to 2003. From the analysis from the macroscopic perspective we know that Kunming is the fastest-growing one among the five cities in Southwestern China, relatively fast cities were Chongqing and Sichuan, relatively slow cities were Yunnan, Guizhou and Xizang.It developed rapidly too form 2003 to 2013. During this period of time Chongqing is the fastest-growing one among the five cities in Southwestern China, relatively fast cities were Kunming and Sichuan, relatively slow cities were Yunnan, Guizhou and Xizang.(4) 1993-2003, the expansion area in Southwestern China was 1529Km2,the rate of city expansion was large, which indicated that the development in vertical direction was more remarkable in the ten years.2003-2013, urban expansion area was 4036 Km, the rate of city expansion and acceleration were also large, which showed mainly horizontal development in Southwestern China.(5) 1993-2013, Chongqing’s built-up area present expansion of the north and the west,which is Yubei district and Bishan county;Kunming’s built-up area present expansion of the south,which is Chenggong district.In this thesis, we used the model of DMSP/OLS night light data to finish the research, the model was currently a good source to observate human activities trajectory and evaluate the urbanization comprehensive level. We found that the model had great advantage and potential in extracting the large scale urbanization information. It is very necessary to do some following research work.