EAR-PF: Present and future flood mitigation services of wetland infrastructure across scales

暴风雨期间的洪水已经成为城市中的一个主要问题。城市可能会经历这种洪水，原因是路面和屋顶的数量增加，暴风雨的频率增加，更强烈的暴风雨，或者城市和气候的这些特征的综合作用。在全球许多城市，特别是在美国，极端降雨引发的洪水可能会特别伤害那些已经面临经济压力的人、种族和少数民族，以及同时属于这两个类别的人。各城市正试图通过改变城市的建设方式来减少强风暴造成的洪水威胁。美国和世界各地的许多城市都在考虑建设湿地或包括自然湿地，以便将水安全地留在城市里，并从城市中的人们手中移走。然而，这些想法和做法是新的，城市需要了解更多关于城市湿地是否以及如何降低洪水风险的问题。此外，随着当地和全球气候的变化，城市不了解湿地是否以及如何有效地防止城市洪水泛滥。在这项研究中，将对两个拥有丰富湿地的城市(美国俄勒冈州格雷沙姆和智利雷吉奥斯的瓦尔迪瓦)进行研究和建模，以了解拥有湿地的城市在当前和未来如何应对风暴。通过收集湿地可能降低洪水风险的三种主要方式的数据并建立模型，这项研究将呈现内陆城市湿地对洪水风险的影响的整体图景。参与这项研究的研究人员将直接与受洪灾影响的社区合作，以确定过去洪灾风险较高的地区，并教育利益相关者了解他们未来的洪灾风险。从这项工作中吸取的经验教训将通过与洪水风险管理人员的合作被纳入每个城市的洪水风险计划中。冲积性洪水是指当降雨率超过天然和工程排水系统的去除速度时发生的洪水，在地表覆盖率不断增加、频繁发生的强烈风暴、日益强烈的风暴或各种这些特征的城市中，已成为人们主要关注的问题。洪涝灾害可能会给城市造成巨大的经济损失，并导致生命损失。在全球许多城市，特别是在美国，洪灾对边缘化群体以及种族和少数民族造成了不成比例的影响。随着洪灾风险和影响的恶化，城市正在寻求新的发展形式，包括恢复或建设湿地，或将所谓的残余湿地纳入城市结构。然而，城市地区的内陆湿地是否以及如何降低洪灾风险还处于早期阶段，研究通常不会审查适当规模的湿地的累积洪灾风险降低效果：城市。研究通常也不会研究未来气候条件下的洪灾风险，而只研究未来2到10年后的风险。在这项研究中，湿地储存、渗透和蒸散对洪水风险的影响将扩大到美国俄勒冈州格雷沙姆和智利雷吉奥斯的瓦尔迪瓦的整个城市，这两个城市都具有广泛的湿地覆盖范围。数据收集将通过持续监测地表储存和土壤储存和植物蒸腾的概观调查来完成。这些数据将用于重建城市湿地在雨水管理模型中的关键水文功能，进而用于评估典型(10年)和更极端(100年)风暴期间的雨水管理系统的性能。据预测，到2100年，这样的风暴将在这些研究城市变得更加频繁。通过考虑湿地可提供洪涝风险的三种主要水文机制--滞留、入渗和蒸腾作用，本研究的结果将呈现内陆城市湿地对洪涝风险影响的整体图景。通过与每个城市受洪灾影响的社区直接合作，参与这项研究的研究人员将确定过去洪灾风险较高的地区，并教育社区了解未来的洪灾风险。通过直接与研究城市的洪水风险管理人员合作，这项工作的重要教训将被纳入每个城市的洪水风险计划。此外，这将是少数几项试图将绿色基础设施，特别是湿地的影响扩大到城市规模的研究之一。这将是将绿色基础设施中的蒸腾作用扩大到城市规模的第一项研究。这一切都将使用一种其他研究人员或实践者尚未采用的混合方法来完成。这一奖项反映了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。

Flooding during intense storms has become a major concern in cities. Cities may experience this kind of flooding due to increasing amounts of pavement and roofs, an increased frequency of storms, more intense storms, or an assortment of these features of the city and climate. In many cities across the globe, and particularly in the U.S., flooding from extreme rainfall may especially harm people who are already financially stressed, racial and ethnic minorities, and people who fit in both of these categories. Cities are trying to reduce the threat of flooding caused by intense storms by changing how cities are built. Many cities in the U.S. and across the world are considering constructing wetlands or including natural wetlands in order to trap and move water safely away from people in the city. However, these ideas and practices are new, and there is much more that cities need to understand about if and how wetlands in cities can reduce flood risk. Also, cities do not understand whether and how well wetlands might prevent flooding in cities as the local and global climate changes. In this study, two cities with abundant wetlands (Gresham, OR, USA and Valdivia, Región de los Ríos, Chile) will be studied and modeled in order to understand how cities with wetlands respond to storms in the present day and in the future. By collecting data on and modeling three primary ways by which wetlands may reduce flood risk—storing water on the surface, allowing water to seep through the ground, and having plants consume water—this study will present a holistic picture of the impacts of inland urban wetlands on pluvial flood risk. Researchers involved in this study will work directly with communities impacted by flooding to identify areas of high past flood risk and educate stakeholders about their future flood risk. Lessons learned through this work will be incorporated in flood risk plans for each city through engagement with flood risk managers.Pluvial flooding, which is flooding that occurs when rates of precipitation exceed rates of removal by natural and engineered drainage systems, has become a major concern in cities with increasing impermeable surface cover, recurring intense storms, increasingly intense storms, or an assortment of these characteristics. Pluvial flooding may cause substantial monetary damage to cities and lead to loss of life. In many cities across the globe, particularly in the U.S., pluvial flooding disproportionately impacts marginalized groups and racial and ethnic minorities. As pluvial flood risk and impacts worsen, cities are looking to new forms of development that include restoring or constructing wetlands, or incorporating so-called remnant wetlands into the urban fabric. However, whether and how inland wetlands in urban areas can reduce pluvial flood risk is inchoate, and studies normally do not examine the cumulative flood risk reduction effect of wetlands at the appropriate scale: the city. Nor do studies typically examine pluvial flood risk under future climate conditions, instead only examining risk 2 to 10 years into the future. In this study, the effects of wetland storage, infiltration, and evapotranspiration on pluvial flood risk will be scaled-up to the whole city in Gresham, Oregon, USA, and Valdivia, Región de los Ríos, Chile, which both feature extensive wetland coverage. Data collection will be accomplished through continuous monitoring of surface storage and synoptic surveys of soil storage and plant transpiration. These data will serve to reconstruct key hydrologic functions of urban wetlands in a stormwater management model, which will in turn be used to estimate stormwater management system performance during typical (10-year) and more extreme (100-year) storms. Such storms are predicted to become more frequent in these study cities by the year 2100. By considering three primary hydrologic mechanisms by which wetlands may provide pluvial flood risk reduction—retention, infiltration, and transpiration—the results of this study will present a holistic picture of the impacts of inland urban wetlands on pluvial flood risk. By working directly with communities impacted by flooding in each city, researchers involved in this study will identify areas of high past flood risk and educate communities about their future flood risk. By working directly with flood risk managers in the study cities, the salient lessons this work will be incorporated in flood risk plans for each city. Furthermore, this will be one of few studies to attempt to scale up the effects of green infrastructure, particularly wetlands, to the city scale. This will be the first study to scale up transpiration in green infrastructure to the city scale. This will all be accomplished using a mixed methodology that has not yet been pursued by other researchers or practitioners.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.