Integrating issues of scale and benefits into a novel planning framework for nature-based solutions to urban flooding

目前，关于蓝绿基础设施、基于自然解决方案的洪水管理以及城市洪水管理的文献大量存在。然而，在干预措施的规模和时间、这些计划可提供的多种效益的评价和平衡以及用于设计和评估这些方法的方法方面存在着重大差距。最近的气候文献表明，下个世纪，世界上许多地区城市洪水的频率和严重程度可能会增加。持续的城市化和在洪泛区建设等趋势也增加了脆弱性和危害的规模，对城市洪水管理系统的需求产生了重大变化。这些因素，加上传统洪水管理的高成本和环境影响，导致在城市洪水管理方面向更加绿色的技术迈进了一大步。大规模的基于自然的城市洪水管理也开始在更发达的国家发展成为一个领域，例如中国的海绵城市概念，之前在赫尔围绕城市地表水管理计划的工作，以及最近在荷兰各地开展的项目。在低收入和中等收入国家，在许多情况下，SuDS或类似的技术已经在城市中实施，要么在全市范围内实施，要么在某些地区实施。该项目将评估这些不同的方法，并了解如何利用干预措施的规模和时机来最大限度地为目标城市地区提供利益。该项目的主要目的是建立一种最佳方法，使用基于蓝绿色基础设施的方法作为城市洪水的解决方案，同时为目标地区提供更广泛的利益。相关的研究问题可能会考虑(1)在城市规划过程的哪个阶段应该整合蓝绿基础设施方法以提供最大的洪水管理效益？这个最大收益水平是多少？(2)以最佳防洪管理为目标如何限制/影响蓝绿基础设施的其他积极效益？如何管理这些权衡？(3)为此目的，应在何种空间尺度上设计蓝绿基础设施？(全市综合规划？区?等等)。(4)上述发现如何受到气候变化可能进展的影响？（增加洪水的频率/严重程度，改变绿色基础设施所需服务的优先次序等）。方法，但可能包括以下方法：(1)利益相关者参与方法，如城市规划者的焦点小组；(2)利用气候模式数据来近似未来洪水事件的震级和频率变化；(3)基于假设修正城市布局的洪水事件水文模拟；(4)利用9m2的降雨模拟器，研究不同绿色基础设施布置下的雨水泛滥情况。该项目目前没有一个主要关注的具体地理位置，任何关于这方面的决定都可能取决于潜在影响伙伴开展业务的地区。该项目旨在支持加强采用蓝绿基础设施和基于自然的解决方案方法，以解决低收入、中等收入和高收入国家（取决于项目所涉及的地点）的城市洪水问题。该项目的主要成果应该是开发蓝绿色城市洪水管理建模的新方法，以及支持工程师和规划者设计干预措施的决策框架。这将有助于在易受洪水影响的城市地区更好地提供生态系统服务。

Currently, extensive literature exists on blue-green infrastructure, flood management through nature-based solutions, and urban flood management. However, significant gaps exist around the scale and timing of interventions, the evaluation and balancing of the multiple benefits such schemes can provide, and the methodologies used to design and assess these approaches. Recent climate literature indicates that the frequency and severity of urban flooding is likely to increase in many areas of the world in the next century. Continued urbanization and trends such as building on floodplains also increase the scale of vulnerability as well as that of the hazards, creating significant changes in demand on urban flood management systems. These factors, combined with the high cost and environmental impacts of traditional flood management, have led to a significant move towards greener techniques in urban flood management. Large scale nature based urban flood management is also beginning to evolve as a field in more developed countries, with examples such as the Chinese sponge city concept, previous work in Hull around the city's surface water management plan, and recent development of projects throughout the Netherlands. In low- and middle-income countries, there are many cases where SuDS, or similar technologies, have been implemented in cities, either citywide or within certain areas. This project will assess these different approaches, and build an understanding of how the scale and timing of interventions can be used to maximise the benefits provided to the targeted urban areas.The main aim of the project is to establish an optimal method for using blue-green infrastructure-based approaches as a solution for urban flooding while providing wider benefits to the target area. Related research questions are likely to consider (1) At what stage of the city planning process should blue-green infrastructure approaches be integrated to offer maximum flood management benefit? What is this maximum benefit level? (2) How does aiming for optimal flood management limit/affect other positive benefits of blue-green infrastructure? How can these trade-offs be managed? (3) At what spatial scale should blue-green infrastructure approaches be designed for this purpose? (Citywide integrated plans? By district? Etc). (4) How are the above findings affected by the likely progression of climate change? (Increasing flood frequency/severity, shifting priorities in the kinds of services desired from green infrastructure, etc.).Methodologies but are likely to comprise the following approaches: (1) Stakeholder engagement approaches such as focus groups of urban planners; (2) Use of climate model data to approximate changes in the magnitude and frequency of future flood events; (3) Hydrological modelling of flood events on hypothetically modified city layouts; (4) Use of 9m2 rainfall simulator to investigate pluvial flooding on different green infrastructure arrangements. This project does not currently have a specific geographic location of primary focus, any decisions on this will likely depend on the areas where potential impact partners are operating.It is intended that this project will support enhanced adoption of blue-green infrastructure and nature-based solutions approaches in order to address urban flooding throughout low, middle, and high-income countries (subject to the locations addressed in the project). The major outcomes of this project should be development of the novel methodologies for the modelling of blue-green urban flood management, and a decision-making framework to support engineers and planners in the designing of interventions. This will allow for the better delivery of ecosystem services within flood-prone urban areas.