The City Gravity Migration of the Urban Agglomeration in the Middle Reach of Yangtze River Based on DMSP Nighttime Light

The urban agglomerations in the middle reaches of the Yangtze River occupy an important position in the regional development pattern of China. Grasping the spatial and temporal development pattern of urban agglomerations accurately is of great significance for the planning and development of urban agglomerations. This paper selects the DMSP/OLS nighttime stable lighting data from year 1993 to year 2011, extracts the annual urban land area of 33 cities in the city group based on the threshold value, and calculates the total annual nighttime light intensity value and the growth rate of each city. By using the center of gravity model and statistical data, the distances and angles of shifts in the centers of gravity of the three major urban agglomerations in the middle reaches of the Yangtze River are explored. Studies have shown that in the past 20 years, the urban agglomeration in the middle reaches of the Yangtze River have achieved rapid development during the year 1993 to year 2011, and the total nighttime light has increased by about 5 times. The center of gravity of urban agglomerations in the middle reaches of the Yangtze River has gradually shifted from the northwest to the southeast, and the migration distance has gradually become smaller since 2004, and the center of gravity of urban agglomerations has gradually stabilized.