论文标题
COVID-19及其基本机制的通用城市扩散模式
Universal Urban Spreading Pattern of COVID-19 and Its Underlying Mechanism
论文作者
论文摘要
目前,Covid-19的全球状况正在加剧,紧迫地呼吁采取有效的控制和预防措施。了解Covid-19的扩散模式已被广泛认为是实施非药物措施的重要步骤。先前的研究在大规模(例如,国际或州际)场景中调查了这一问题,而城市扩散模式仍然是一个悬而未决的问题。在这里,我们通过利用在中国9个城市中利用197,808个智能手机用户(包括17,808个匿名确认案件)的轨迹数据来填补这一空白。我们在所有城市发现了普遍的扩散模式:确认案例的空间分布遵循幂律样模型,而扩散的质心则存在时间不变。此外,我们揭示了城市中的人类流动性驱动时空传播过程:长期的平均行进距离导致散布半径扩散的高增长率和确认病例的广泛空间扩散。有了这样的见解,我们采用肯德尔模型来模拟Covid-19的城市扩散,这可以很好地适合真正的扩散过程。我们的结果揭示了Covid-19的时空城市演变背后的基本机制,并可用于评估许多政府实施的移动性限制政策的绩效,并估计Covid-19的不断发展的扩散状况。
Currently, the global situation of COVID-19 is aggravating, pressingly calling for efficient control and prevention measures. Understanding spreading pattern of COVID-19 has been widely recognized as a vital step for implementing non-pharmaceutical measures. Previous studies investigated such an issue in large-scale (e.g., inter-country or inter-state) scenarios while urban spreading pattern still remains an open issue. Here, we fill this gap by leveraging the trajectory data of 197,808 smartphone users (including 17,808 anonymous confirmed cases) in 9 cities in China. We find a universal spreading pattern in all cities: the spatial distribution of confirmed cases follows a power-law-like model and the spreading centroid is time-invariant. Moreover, we reveal that human mobility in a city drives the spatialtemporal spreading process: long average travelling distance results in a high growth rate of spreading radius and wide spatial diffusion of confirmed cases. With such insight, we adopt Kendall model to simulate urban spreading of COVID-19 that can well fit the real spreading process. Our results unveil the underlying mechanism behind the spatial-temporal urban evolution of COVID-19, and can be used to evaluate the performance of mobility restriction policies implemented by many governments and to estimate the evolving spreading situation of COVID-19.