Spatio-temporal heterogeneity of the influencing factors in the expansion of urban built-up areas in Shandong counties
In order to improve the efficiency of urban land use and promote the sustainable development of urban economy in Shandong province,this paper uses exploratory spatial analysis,GW summary statistics and MGWR model to analyze the spatio-temporal heterogeneity of urban built-up areas expansion and its influencing factors based on the urban land expansion datasets of 137 counties in the province in 2010,2015 and 2021.The results show that:(1)The overall county-level built-up area in Shandong was expanding continually with the spatial distribution characteristics that the area was larger in the central and eastern regions of the province than that in other regions,forming an urban sprawl tendency with Jinan and Qingdao as the"dual cores";(2)The driving mechanism of the expansion of the built-up area transformed from"economic urbanization as the main driving force,and population urbanization as the auxiliary driving force"to"population urbanization as the main driving force,and economic urbanization as the auxiliary driving force",having the problem of incongruity and mismatch between the two;(3)The impact of land-average investment on built-up area expansion evolved from an overall negative effect to a situation where positive and negative effects coexist,with 51%of counties and districts showing no significant negative effects by 2021,indicating that more than half of them had lost their potential for intrinsic development of urban construction land;(4)The influences of economic development,fiscal expenditure gap rate,and export dependence were relatively small,but each variable had significant spatio-temporal heterogeneity effects.Among them,economic development transitioned from an overall positive effect to a situation where positive and negative effects coexist and then evolved into an overall positive effect;the fiscal expenditure gap rate transitioned from an overall negative effect to an enhanced situation of positive and negative effects and then reverted to a weakened overall negative effect;and the export dependence transitioned from an overall positive effect to an overall negative effect.In view of the significant spatio-temporal heterogeneity of the driving mechanism for the expansion of the county-level built-up area in Shandong,the coordinated and sustainable development of the urbanization in counties should be promoted through comprehensive and differential policies.
Shandongcounty-level citiesGW modelurban land expansionspatio-temporal heterogeneity