Floods cause the most damage of all natural disasters in the United States. Households and communities receive much of their information on flood hazards from maps produced by the Federal Emergency Management Agency (FEMA). These maps have been criticized for many reasons: they use poor data, do not reflect a changing climate, do not capture rainfall flooding, create misperceptions about risk, and are often out of date. We examine this last concern, investigating how long it takes updated county‐level flood maps to be adopted across the country, using a unique nationwide data set from June 2014 to 2017. We find substantial heterogeneity in the time to adopt maps, with multiple outliers where the process far exceeds the time FEMA has estimated should be standard. Many factors may generate delay, including time for new data collection, technical challenges to revised maps, and community opposition. We also find there are differences in appeal rates and the timing of map revisions based on those appeals between inland and coastal counties and between higher and lower income communities. These correlations raise important questions for policymakers and scholars about the equity and accuracy of the nation's current approach to mapping changing flood risk.

中文翻译：

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漫长的采用之路：采用更新的县级洪水保险费率图需要多长时间？

在美国，洪水对所有自然灾害造成的破坏最大。家庭和社区从联邦紧急事务管理局（FEMA）制作的地图上收到许多有关洪水灾害的信息。这些地图因许多原因而受到批评：它们使用的数据不佳，不反映气候变化，没有捕获降雨泛滥，对风险有误解，并且经常过时。我们使用2014年6月至2017年全国范围内的独特数据集，研究了最后一个问题，调查了在全国范围内采用更新的县级洪水地图需要多长时间。我们发现，在采用多种异常值时，采用地图的时间存在很大异质性该过程远远超出FEMA估计的时间应该是标准的。许多因素可能会产生延迟，包括收集新数据的时间，修订地图面临的技术挑战以及社区的反对。我们还发现，基于内陆县与沿海县之间以及高收入和低收入社区之间的上诉，上诉率和地图修订时间存在差异。这些相互关系为政策制定者和学者们提出了重要的问题，涉及该国目前用于绘制不断变化的洪水风险的方法的公平性和准确性。