Significant negative impacts are observed in productivity, economy, and social well-being because of the reduced human activity due to extreme events. Community resilience is an important concept to understand and quantify the impacts of an extreme event to population activity. Resilience is generally defined as the ability of a system to manage shocks and return to a steady state in response to an extreme event. In this paper, we analyze aggregate location data from Facebook in response to Hurricane Ida. Using changes in the number of Facebook users before, during, and after the disaster, we empirically define and quantify community resilience as a function of the magnitude of impact and the time to recover from the extreme situation. We measure resilience and the transient loss of resilience in population activity for the affected communities in Louisiana. The loss in resilience of the affected communities was explained by three types of factors, including disruption in physical infrastructures, disaster conditions due to hurricanes, and socio-economic characteristics of a community. We find that a greater loss in community resilience is associated with factors such as disruptions in power and transportation services and disaster conditions. We also find socioeconomic disparities in loss of resilience with respect to median income of a community. Understanding community resilience using the decreased population activity levels due to a disaster and the factors associated with loss in community resilience will allow us to improve hazard preparedness, enhance disaster management practices, and create better recovery policies towards strengthening infrastructure and community resilience.

翻译：极端事件导致的人类活动减少对生产力、经济和社会福祉产生了显著的负面影响。社区韧性是理解和量化极端事件对人口活动影响的重要概念。韧性通常被定义为系统应对冲击并在极端事件后恢复至稳定状态的能力。本文利用Facebook的聚合位置数据，分析飓风艾达（Hurricane Ida）的响应过程。通过灾前、灾中和灾后Facebook用户数量的变化，我们以影响幅度和从极端状况中恢复所需的时间为函数，经验性地定义并量化了社区韧性。我们测量了路易斯安那州受影响社区的人口活动韧性及其瞬态韧性损失。受影响社区的韧性损失可由三类因素解释，包括物理基础设施的中断、飓风导致的灾害条件以及社区的社会经济特征。我们发现，社区韧性损失越大，与电力和交通服务中断及灾害条件等因素的关联越强。我们还发现，韧性损失在社区中位收入方面存在社会经济差异。通过理解灾害导致的人口活动水平下降所反映的社区韧性，以及影响社区韧性损失的相关因素，我们得以改进灾害防备、优化灾害管理实践，并制定旨在强化基础设施和社区韧性的更优恢复政策。