Compiling and disseminating information about incidents and disasters are key to disaster management and relief. But due to inherent limitations of the acquisition process, the required information is often incomplete or missing altogether. To fill these gaps, citizen observations spread through social media are widely considered to be a promising source of relevant information, and many studies propose new methods to tap this resource. Yet, the overarching question of whether and under which circumstances social media can supply relevant information (both qualitatively and quantitatively) still remains unanswered. To shed some light on this question, we review 37 disaster and incident databases covering 27 incident types, compile a unified overview of the contained data and their collection processes, and identify the missing or incomplete information. The resulting data collection reveals six major use cases for social media analysis in incident data collection: (1) impact assessment and verification of model predictions, (2) narrative generation, (3) recruiting citizen volunteers, (4) supporting weakly institutionalized areas, (5) narrowing surveillance areas, and (6) reporting triggers for periodical surveillance. Furthermore, we discuss the benefits and shortcomings of using social media data for closing information gaps related to incidents and disasters.

中文翻译：

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来自社交媒体的灾难数据的机会和风险：对事件信息的系统回顾

汇编和传播有关事件和灾难的信息是灾难管理和救济的关键。但是由于采集过程的固有局限性，所需的信息通常不完整或完全丢失。为了填补这些空白，通过社交媒体传播的公民意见被广泛认为是相关信息的有希望的来源，许多研究提出了利用这种资源的新方法。但是，关于社交媒体是否以及在什么情况下可以提供相关信息（定性和定量）的总体问题仍然没有得到解答。为了阐明这个问题，我们回顾了涵盖27种事件类型的37个灾难和事件数据库，对所包含的数据及其收集过程进行了统一的概述，并找出缺失或不完整的信息。收集到的数据揭示了事件数据收集中社交媒体分析的六个主要用例：（1）影响评估和模型预测验证；（2）叙事产生；（3）招募公民志愿者；（4）支持机构薄弱的地区； （5）缩小监视范围，以及（6）报告定期监视的触发因素。此外，我们讨论了使用社交媒体数据来弥补与事件和灾难相关的信息鸿沟的利弊。（5）缩小监视范围，以及（6）报告定期监视的触发因素。此外，我们讨论了使用社交媒体数据来弥补与事件和灾难相关的信息鸿沟的利弊。（5）缩小监视范围，以及（6）报告定期监视的触发因素。此外，我们讨论了使用社交媒体数据来弥补与事件和灾难相关的信息鸿沟的利弊。