Spatiotemporal differentiation and influencing mechanism of urban expansion in the Yangtze River Economic Belt,China
Nowadays,the disordered expansion of urban land has become an important problem on China's urbanization.Urban population growth is widely recognized as a crucial driver of urban spatial expansion.Therefore,it is necessary to clarify the spatiotemporal differentiation characteristics of urban expansion and understand the relationship between urban population size and urban expansion.Based on Landsat TM/OLI remote sensing images and socioeconomic statistics data,this paper identified the urban land in the Yangtze River Economic Belt(YREB),China,between 1990 to 2020.This was achieved by combining object-oriented automatic extraction and human-computer interaction visual interpretation.The study then examined the spatiotemporal differentiation characteristics of urban expansion at difference scales using expansion speed,expansion difference index,kernel density analysis and spatial autocorrelation.Finally,the relationship between urban population size and urban expansion in different regions was investigated using the Two-way Fixed Effects Model.The main results are as follows:(1)After 2015,urban expansion speed decreased significantly in different parts of the YREB.Moreover,the time series characteristics of urban expansion in the cities of the upper and middle reaches were found to be different from those in the lower reaches.The upper reaches had higher expansion speed than the middle reaches after 2010.Spatially,the urban expansion in the YREB shows significant spatial heterogeneity.High-speed expansion areas have shifted from east to west,and the differences in urban land scale between the upper-middle and the lower reaches tend to converge.Urban expansion in the lower reaches exhibits strong spatial dependency,while in the middle-upper reaches,there is no significant spatial autocorrelation.(2)The relationship between urban population size and urban expansion differs significantly among different regions.The upper reaches show a negative correlation,while the middle-lower reaches exhibit a"U-shaped"relationship.This indicates that there is no obvious over-expansion of population size in the upper reaches,whereas there is in the middle-lower reaches.Residents in the middle reaches have demonstrated a higher sensitivity to urban comfort and quality of life.Finally,the study provides regional policy recommendations,aiming to offer scientific references for targeted urban policies and promote high-quality urban development.
urban expansionspatiotemporal differentiationurban population sizefixed effects modelurban expansion difference indexYangtze River Economic Belt
万方数据
维普
