Analysis of the spatial expansion characteristics of built-up area of eight provinces along the grand canal using DMSP-OLS nighttime lights data

摘要

Since the 1990s, the urban sprawl phenomenon has become very obvious in China due to the fast pace of urbanization. The DMSP-OLS image of 1992, 1998, 2003, 2008, and 2013 were used to extract the built-up areas of the eight provinces along the Grand Canal. Then we analyzed the spatial expansion characteristics of built-up area in the eight provinces. The night-time lights threshold for detecting built-up area is determined by built-up area in China Statistical Yearbook, and spatial precision evaluation is made by using the land cover products of ESA CCI. The spatial expansion laws, spatial expansion intensity and spatial expansion type were calculated. At the same time, the relationship between urban expansion and economic growth was analyzed by using the urban area-GDP elasticity coefficient .The results show that the use of DMSP-OLS stable light data can quickly and accurately extract urban built-up areas. Compared with the statistical data, the average relative error is 5.15%. From the perspective of the expansion area, built-up area of each province have been expanded, but the size of the expansion area is different. The cities in Jiangsu, Shandong, and Zhejiang have the largest area of urban expansion. The three provinces ' urban expansion area accounts for 59% of the total area. From the perspective of the spatial expansion intensity, the intensity of 1998-2003 was the largest. However, judging from the urban area-GDP elasticity coefficient, there was an inconsistency between urban area and economic growth during1998-2003. After 2003, the economic benefits of urban land use increased gradually. Urban land use in Beijing and Tianjin is more intensive.