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

目前，存在大量关于蓝绿基础设施、通过基于自然的解决方案进行洪水管理和城市洪水管理的文献。然而，在干预措施的规模和时机、评估和平衡这些计划可以提供的多种效益以及设计和评估这些办法所使用的方法等方面存在重大差距。最近的气候文献表明，在下一个世纪，世界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平原上建房等趋势也增加了脆弱性和危害的规模，使对城市洪水管理系统的需求发生了重大变化。这些因素，加上传统洪水管理的高成本和环境影响，导致了城市洪水管理向绿色技术的重大转变。大规模的基于自然的城市洪水管理也开始在发达国家发展成为一个领域，例如中国的海绵城市概念，船体以前围绕城市地表水管理计划的工作，以及最近在荷兰各地开发的项目。在低收入和中等收入国家，有许多情况下，SuDS或类似技术已在城市范围内或某些地区内实施。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间，以最大限度地提高目标城市地区的效益。该项目的主要目的是建立一个最佳方法，使用蓝绿色基础设施为基础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）在城市规划过程中的什么阶段，蓝绿基础设施的方法应该被整合，以提供最大的洪水管理效益？这一最高福利水平是多少？(2)以最佳洪水管理为目标如何限制/影响蓝绿基础设施的其他积极效益？如何管理这些权衡取舍？(3)为此目的，应在多大的空间尺度上设计蓝绿基础设施办法？（全市综合规划？按地区？等）。(4)气候变化的可能进展如何影响上述研究结果？（增加洪水频率/严重程度，改变绿色基础设施所需服务种类的优先级等）。方法学，但可能包括以下方法：（1）利害关系方参与的方法，如城市规划者重点小组;（2）利用气候模型数据估算未来洪水事件的规模和频率的变化;（3）假设修改城市布局的洪水事件水文模型;（4）使用9平方米的降雨模拟器，研究不同绿色基础设施布置的洪泛情况。该项目目前没有一个具体的地理位置作为主要关注点，任何关于这一点的决定都可能取决于潜在的影响合作伙伴正在开展业务的地区。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的城市洪水问题（取决于项目所涉及的地点）。该项目的主要成果应该是开发蓝绿城市洪水管理建模的新方法，以及支持工程师和规划师设计干预措施的决策框架。这将有助于在洪水易发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.