Spatial-Temporal Evolution Characteristics of Urban Expansion in Chengdu-Chongqing Twin-City Economic Circle
Chengdu-Chongqing Twin-City Economic Circle is the fourth-largest urban agglomeration in China,whose spatial and temporal urban expansion characteristics offer references for regional planning and decision making.We extract the urban expansion dynamics(1990-2019)of 45 administrative divisions from the Chengdu-Chongqing area using Google Earth Engine(GEE),compare and analyze the expansion characteristics of these cities based on circular-gradient analysis and inversed S-function.The results show that:1)The urban expansions pose significant spatial differences:Chengdu and Chongqing,the two core urban areas,have the fastest urbanization process and drive the urban development of nearby cities,the small and medium-sized cities have a relatively slow expansion process,and their urban system structure and regional synergy need to be strengthened.2)The urban compactness(Kp)and expansion speed(D)reveal that all urban radiuses expanded over time,the compactness decreased in most large and medium-sized cities but increased in some small cities.3)The urban formation and evolution of the cities can be divided into four types:megacities and large cities are of the high-speed development type,regional central cities are of the agglomeration growth type,medium-sized cities in the Chengdu-Chongqing connection region are of the decentralized development type,and small cities are of the development lag type.
Chengdu-Chongqing Twin-City Economic Circleurban expansionurban formgradient analysisurban land density
万方数据
维普
