城市蔓延多尺度测度和时空差异研究

Multi-scale measurement and temporal and spatial differences research of urban sprawl

针对既有城市蔓延测度研究中测度单元和尺度单一的问题,该文通过构建本地化的加权城市扩散模型,以北京市为例,探究城区、城区缓冲区、市辖区等不同尺度对城市蔓延测度的影响,并在1km^(2)格网、区县、主体功能区等不同单元上分析2000—2020年的城市蔓延空间差异特征。结果表明:①2000—2020年,高度蔓延地区随时间变化不断向城区外围转移。其中,2000年城区尺度下的城市蔓延程度最高,而2010、2020年则变化为城区3km缓冲区尺度;②城市蔓延受交通辐射影响较大,且高度蔓延地区由高速公路附近区域逐渐向环城市功能拓展区的区域演变;③中心城区蔓延程度呈现降低趋势,其中首都功能核心区中蔓延程度始终保持最低水平。该研究结果可为城市治理、城市更新与国土空间优化提供参考依据。

Aiming at the problem of a single measurement unit and scale in established urban sprawl measurement studies,this paper constructs a localized weighted urban proliferation(WUP)model.Taking Beijing as an example,we explore the effects of different scales on the urban sprawl measurement.We also analyze the spatial variation characteristics of urban sprawl from 2000to 2020on different units.The results show that:①From 2000to 2020,the highly sprawl areas keep shifting to the periphery of urban areas over time.Among them,the highest level of urban sprawl was observed at the urban scale in 2000.And in 2010and 2020,it changed to the 3km buffer scale in urban areas.②Urban sprawl is strongly influenced by traffic radiation.And the high sprawl area gradually evolves from the area near the highway to the area around the urban functional expansion area.③The sprawl degree of the central city shows a decreasing trend.Among them,the degree of sprawl in the core area of the capital function is always kept at the lowest level.This paper realizes urban sprawl measures at different scales in Beijing through a localized WUP model.And it reveals the spatial and temporal variation characteristics of urban sprawl within different study units.The research results can provide a reference basis for urban governance,urban renewal and territorial space optimization.