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威胁，全国各地洪水多发地区仍在继续修建新房。联邦、州和地方政府可以使用一系列政策和计划来限制或减少泛滥平原的建设，促进更安全地区的发展。该奖项支持研究，以探索为什么一些社区能够使用这些工具在不在泛滥平原建设的情况下发展，以及为什么其他社区没有。研究人员开发了一个指数，以确定成功限制洪水易发社区的社区，并使用案例研究来探索使城镇能够成功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，有效管理泛滥平原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协作和学习，以及培训多样化、包容性的下一代气候适应研究人员和实践者。第一步是测量美国各城市的泛滥平原发展情况，填补一个关键的数据缺口。利用房地产数据集、物业收购地点和遥感土地利用信息，将2001至2016年间住房单位的净变化和不透水面积的增加与受监管的100年泛滥平原进行了对比。然后，通过根据市政当局面临的洪水风险和总体发展情况进行比例调整，将原始测量数据转换为发展指数。通过创建泛滥平原开发的标准化措施，这一步骤使战略案例选择和对各种泛滥平原开发成果的社区调查成为可能，而这在目前是不可能的。其次，利用地理、社会和经济因素分析了滩地开发成果的模式。第三，该项目将使用比较案例研究来解释为什么社区在洪泛区开发成果上存在差异。具体地说，这一部分考察了法律和监管工具的采用、目的和实施如何影响泛滥平原的开发成果，以避免或退出泛滥平原。城市是成对选择的：那些泛滥平原开发有限的城市，以及那些没有的城市。访谈和文件分析被用来评估采用了什么法律和监管工具，目的是什么，以及如何实施这些工具，同时考虑到工具的设计和执行。通过首先创建一种衡量开发成果的方法，该项目提供了对泛滥平原开发的两种模式以及法律和监管政策如何以及为什么影响这些结果的独特洞察。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.