Collaborative Research: Floodplain Management in the United States: Where, Why, and How Policies Have Shaped Flood Exposure Outcomes

近4100万美国人面临洪水的危险，全国各地的洪水易发地区仍在建造新房。联邦、州和地方政府可以利用一系列政策和项目来限制或减少洪泛区的建设，促进安全地区的发展。该奖项支持研究探索为什么一些社区能够使用这些工具在洪泛区发展而不建造，为什么其他社区没有。这组科学家开发了一个指数来识别那些成功地限制了容易发生洪水的发展的社区，并使用案例研究来探索使城镇能够成功地限制洪水暴露的背景、行动和政策。随着气候变化导致更强烈的风暴和更高的海平面，有效地管理洪泛区的发展对美国各地社区的健康、繁荣和福祉越来越重要。这项研究将加强研究人员、政策制定者和公众的努力，以建立充满活力的社区，同时限制极端气候造成的破坏。该项目支持洪水管理背景下的合作和学习，以及培养多样化、包容性的下一代气候适应研究人员和实践者。这个项目有三个组成部分。第一步是测量美国各城市洪泛区的发展情况，填补一个关键的数据缺口。利用房地产数据集、物业买断地点和遥感土地利用信息，我们将2001年至2016年住房单位的净变化和不透水地表的增加与100年的监管洪泛平原相关联，制成表格。然后，根据市政当局面临的洪水风险和总体开发情况，将原始测量值转换为发展指数。通过创建洪泛区发展的标准化措施，这一步骤可以对一系列洪泛区发展结果的社区进行战略性案例选择和调查，这在目前是不可能的。其次，利用地理、社会和经济因素分析洪泛平原发展结果的模式。第三，该项目将通过比较案例研究来解释为什么社区在洪泛区开发结果上存在差异。具体而言，本部分考察了避免或退出泛滥平原的法律和监管工具的采用、目的和实施如何影响泛滥平原的发展结果。市政当局是成对选择的：限制洪泛区发展的和没有限制洪泛区发展的。访谈和文件分析用于评估采用了哪些法律和监管工具，出于什么目的，以及如何实现它们，同时考虑到工具设计和执行。通过首先创建一种衡量发展成果的方法，本项目提供了一种独特的视角，深入了解洪泛区发展的两种模式，以及法律和监管政策如何以及为何影响这些成果。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nearly 41 million Americans are at risk of flooding, and new homes continue to be built in flood-prone areas across the country. Federal, state, and local governments can use a range of policies and programs to limit or reduce construction in floodplains and promote development in safer areas. This award supports research to explore why some communities have been able to use these tools to grow without building in floodplains and why others have not. The researchers develop an index to identify communities who have successfully limited flood-prone development, and use case studies to explore the contexts, actions, and policies that enable towns to successfully limit flood exposure. As climate change leads to more intense storms and higher sea levels, effectively managing development in floodplains is increasingly critical to the health, prosperity, and well-being of communities across the United States. The research will enhance efforts by researchers, policymakers, and the public to build vibrant communities while limiting damage from climate extremes. The project supports collaboration and learning across flood management contexts, as well as the training of a diverse, inclusive next generation of climate adaptation researchers and practitioners.This project has three components. The first step is to measure floodplain development in municipalities across the United States, filling a critical data gap. Using real estate datasets, property buyout locations, and remotely sensed land use information, the net change in housing units and the increase in impervious surface from 2001 to 2016 are tabulated in relation to the regulatory 100-year floodplain. Raw measurements are then converted into development indices by scaling based on the municipality’s exposure to flood risk and total development. By creating standardized measures of floodplain development, this step enables strategic case selection and investigation of communities across a range of floodplain development outcomes, which is not currently possible. Second, patterns in floodplain development outcomes are analyzed using geographic, social, and economic factors. Third, the project will explain why communities differ in floodplain development outcomes using comparative case studies. Specifically, this component examines how the adoption, purpose, and implementation of legal and regulatory tools to avoid or retreat from floodplains shape floodplain development outcomes. Municipalities are selected in pairs: those that have limited floodplain development, and those that have not. Interviews and document analysis are used to assess what legal and regulatory tools were adopted, for what purpose, and how they were implemented, considering both tool design and enforcement. By first creating a way to measure development outcomes, this project provides a unique level of insight into both patterns in floodplain development and how and why legal and regulatory policies influence these outcomes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.