Flood Insurance Rate Maps (FIRMs) are produced for the National Flood Insurance Program to depict and manage flood hazard in the United States. While past research has portrayed FIRMs as static maps, property residents and community representatives can propose changes to flood zones on FIRMs. These changes add and remove buildings from flood zones on FIRMs, which raises an important question: are there discernable trends or patterns in these alterations to FIRMs? We use Geographic Information Systems FIRM layers and building footprints to quantify the number of buildings moved in and out of the Special Flood Hazard Area (SFHA) for recently updated FIRMs. Our analysis of building additions and removals from SFHAs at county and census tract scales shows there has been a net change of over 20,000 buildings removed from these SFHAs between preliminary and present FIRM iterations. We also find that SFHAs are more frequently altered in places where median home values are higher, buildings are newer, and percentage of white populations are higher. These findings suggest changes to flood zones on FIRMs occur more often where people have greater socioeconomic means, raising questions of equity for future FIRM appeals and revisions.

中文翻译：

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上诉和修改：对最近更新的洪水保险费率图的更改

洪水保险费率图 (FIRM) 是为国家洪水保险计划制作的，用于描述和管理美国的洪水灾害。虽然过去的研究将 FIRM 描述为静态地图，但房地产居民和社区代表可以提议对 FIRM 上的洪水区进行更改。这些变化在 FIRM 上的洪水区增加和移除建筑物，这就提出了一个重要的问题：在这些对 FIRM 的改变中是否有明显的趋势或模式？我们使用地理信息系统 FIRM 图层和建筑物足迹来量化最近更新的 FIRM 进出特殊洪水灾害区 (SFHA) 的建筑物数量。我们对县级和人口普查区的 SFHA 新增和拆除建筑的分析表明，净变化超过 20，在初步和当前 FIRM 迭代之间，从这些 SFHA 中移除了 000 座建筑物。我们还发现，在房价中值较高、建筑物较新和白人人口比例较高的地方，SFHA 的变化更为频繁。这些发现表明，在人们拥有更大的社会经济手段的地方，FIRM 洪水区的变化更频繁地发生，从而为未来的 FIRM 上诉和修订提出了公平问题。