城市群新冠疫情时空分布格局与分异机制的地理探测

Spatiotemporal distribution pattern of the COVID⁃19 epidemic and geographical detection

自从2019年12月湖北武汉爆发新型冠状病毒(COVID⁃19)以来,疫情在全国范围内迅速传播并蔓延。城市群既是我国新型城镇化主体特定的空间组织形态,也是相互连接的城市网,集合了相当数量不同性质、类型和等级规模的城市,城市群经济发展程度较高、人口密度大,交通发达,是疫情传染扩散-关联的重点区域,因而跨区域感染风险高,联防联控难度大。以疫情集中地区城市群为研究对象,通过核密度分析聚焦重点研究的城市群,从多层空间尺度对疫情在数量、人口迁移和空间分布上进行测度,利用空间自相关分析疫情分布特征,运用地理探测器方法客观地测度城市群疫情发展的差异性主导因素,从景观格局中挖掘相关主导因子,为生态、安全的空间规划和治理提供科学依据和思路。结果显示:①全国范围感染人数核密度高值区的空间分布与长江中游城市群和三大沿海城市群范围耦合,首位核心城市确诊感染数在城市群中占比均较高,城市群疫情扩散分布呈现典型的由核心城市向外辐射的特征,湖北地区迁出的人数对迁往地区的疫情形势构成一定程度的影响;②全国范围的COVID⁃19感染人数和感染增长率分布存在显著空间集聚特征,城市群范围感染人数的空间聚集性从长江中游城市群向其他城市群依次减弱;③地理探测器识别出人口密度、城乡建设、交通、卫生、科技、生态绿地为疫情的主导因素,并且交互后所产生的共同作用增加了对疫情的解释力;④生态与建设用地景观格局对疫情的解释能力较强,其中建设用地的聚集性和生态用地的蔓延性为主要因子。

The epidemic has rapidly spread across China since the outbreak of the novel coronavirus disease 2019(COVID⁃19)in Wuhan,Hubei province in December 2019.Urban agglomerations are not only the main spatial organization forms of China′s new urbanization but also interconnected urban networks that gather a considerable number of cities of different natures,types,and scales.Urban agglomerations with relatively high degrees of economic development,large population densities,and developed transportation are key regions associated with the spread of the epidemic.In these regions,crossregional infection risk is high,and joint prevention and control is difficult.This article takes the urban agglomerations in the epidemic-intensive area as its research object.It focuses on the key urban agglomerations through kernel density analysis;measures the number,population migration,and spatial distribution of the epidemic from multi-spatial scales;uses spatial autocorrelation to analyze the distribution characteristics of the epidemic;and uses the geographic detector method to objectively measure the leading factors of the epidemic in urban agglomerations.The aim of these analyses is to excavate the relevant dominant factors from the landscape pattern to provide scientific basis and ideas for ecological and safe spatial planning and governance.Results show that①the high-kernel density areas of the number of infection cases nationwide is spatially coupled with the four urban agglomerations.The number of confirmed cases in the first core city accounts for a high proportion in the urban agglomerations,and the spread and distribution of the epidemic typically radiates outward from the core city.The outflow of people in Hubei has a certain impact on the epidemic situation in the inflowing area.②There are significant spatial agglomeration characteristics in the number of infection cases and the growth rate of infections nationwide.The spatial agglomeration of the number of infections within the urban agglomerations has gradually weakened from the Middle Yangtze urban agglomeration to other urban agglomerations.③The geographic detector reveals that the population density,urban and rural construction,transportation,health,science and technology,and ecological green space are the dominant factors in the spread of the epidemic,and the combined effect produced by the intersecting factors can increase the explanatory power.④The landscape pattern of ecological and construction land have strong ability to explain the epidemic;aggregation of construction land and extension of ecological land are main factors.