Green Infrastructure: understanding its role in mitigating current and future flood risk in urban areas

仅在英格兰，就有320万户家庭面临地表水泛滥的风险，每年的损失超过3亿英镑。据预测，到2050年代，相关损失的成本可能会增加40%。绿色基础设施（GI）可以通过渗透、截留、蒸腾以及提供临时和更长期的储存来减少进入排水系统的水量。需要证据来了解地理标志在时间和空间上如何、何地以及何时有助于减轻洪水风险。本项目将考虑以下研究问题：*我们如何在我们的洪水风险影响模型中更好地代表绿色基础设施的结构和功能？*我们如何在现有的城市结构中设计绿色基础设施，以最大限度地提高效益和降低成本？*在未来气候条件下，绿色基础设施作为防洪措施的效果如何？该项目将在国家绿色基础设施和城市不同地理标志类型的地点进行一系列对照实验。然后，观测结果将用于CityCAT中可靠且稳健的基于物理的入渗成分，这是一个能够模拟洪水风险的水动力学模型，以及GI在大空间域中以高分辨率降低风险方面的作用。该项目的成果将包括提高对GI性能的理解；评估GI的长期表现和成本，包括管理和维护；并帮助设计未来地理标志战略，以减轻城市地区气候引发的洪水风险。

In England alone, 3.2 million households are located in areas at risk of surface water flooding, with annual damages exceeding £300 million. It is projected that this cost of associated damage could increase by 40% by the 2050s.Green infrastructure (GI) can provide a means of reducing the amount of water entering drainage systems via infiltration, interception, transpiration and providing both temporary and more longer-term storage. Evidence is needed to understand how, where and when GI aids flood risk mitigation over time and space.This project will consider the following research questions:* How can we better represent the structure and function of green infrastructure in our flood risk impact models?* How can we design green infrastructure into the existing urban fabric to maximise benefits and reduce costs? * How effective will green infrastructure be as a flood mitigation measure under future climate?This project will conduct a number of controlled experiments at the National Green Infrastructure Facility and at locations of different GI types across the city. Observations will then be used to inform a reliable and robust physically-based infiltration component in CityCAT, a hydrodynamic model capable of simulating flood risk, and the role of GI in mitigating that risk at high resolutions over large spatial domains. Outcomes from this project will include improved understanding of GI performance; assess long-term performance and costs of GI, including management and maintenance; and aid design of future GI strategies to mitigate climate-induced flood risk in urban areas.