The Research Of Urban Expansion In Xiamen-Zhangzhou-Quanzhou Triangle Area By Using Nighttime Light Imagery

With the accelerated pace of urbanization in China,urban expansion is a very important part of the study of land use and land cover change,which has a far-reaching impact on the sustainable development of the social,economic and ecological environment in the region.Xiamen-Zhangzhou-Quanzhou triangle area is one of the most developed areas in China and Fujian province,which has entered the period of accelerating urbanization,but there is also the problem of out-of-control space expansion.The study of the speed and mode of urban expansion is of great significance for the overall grasp of the process of urban development.The characteristics of remote sensing data which can quickly extract and directly reveal the urban information will play an important role in this kind of research.A large number of studies have shown that,DMSP/OLS and NPP-VIIRS,these two kind of nighttime light data on global scale are effective sources of remote sensing data in monitoring human activities and developing urban researchTaking Xiamen-Zhangzhou-Quanzhou triangle area as the study area,and the DMSP/OLS(1992-2013)and NPP-VIIRS(2014-2017)nighttime light data which suitable for the study areas were selected.Using RS and GIS technology,this study has completed the intercalibration of nighttime light data,urban built-up areas extraction,long time series urban expansion analysis,and analyzed the relationship between the nighttime lightime data and the social and economic indicators.The main contents and conclusions of this paper are as follows:(1)The DMSP/OLS nighttime light data was intercalibated.Due to the OLS sensor does not have on-board-calibrate process,the data we obtained were lacked of comparability between different years.In this paper,the existing research methods were integrated to determine the correction parameters of DMSP/OLS nighttime light data(from 1992 to 2013,a total of 34 images),and the intercalibation of multi-temporal nighttime light data was completed.NPP-VIIRS nighttime light data(from 2014 to 2017,a total of 4 images)were used directly,and the abnormal data were deleted.The treated data could meet the requirement of future using.(2)Using the GIS technology to analyze the nighttime light data in Xiamen-Zhangzhou-Quanzhou triangle area,and the thesis analyzed the dynamic change process of the region’s intensity and DN value in the region during the period of 1992-2013 years.At the same time,a variety of models were constructed to analyze the relationship between the region and the urbanization level,which indicated that the application intensity or gross value of the region could better predicted urbanization in different regions.The main factors of concern should be differentiated according to different cities.(3)The night view index(total DN value)based on NPP-VIIRS data,and the quantitative analysis of the impact of urban expansion on roads and different river basin rivers by using GIS technology to construct buffer zones.The study showed that both of them have an impact on urban expansion,and the influence of the river was greater in this area.In view of the characteristics of urban development in the Min triangle area,this paper reconstructs the urban expansion process of 1992-2017 years in the Xiamen-Zhangzhou-Quanzhou triangle area by using the night light data to extract and expand the urban expansion information.At the same time,it explores the relationship between the night scene index and the urbanization level index and the linear corridor,such as the road and the river flow.It has a certain guiding significance for the sustainable development of the region.