Adaptation strategies to pluvial urban flood risk under UKCP18 climate change scenarios

与夏季对流风暴和冬季锋面风暴有关的强降雨的频率和影响预计将随着未来气候变化而增加。更高强度的降雨在城市地区造成了严重的洪灾挑战，由于现有的基础设施和发展，这限制了缓解选择。地方当局需要在减灾战略中考虑气候变化，目前使用区域气候模型(RCM)，例如英国气象局发布的UKCP09气候预测(Rabb等人，2017年)。这些模型模拟提供了温度、降雨量和湿度等变量在气候变化下可能在区域层面上发生变化的预测。与更传统的全球气候模型(GCM)相比，区域气候模型具有许多优势；它们以更高的空间分辨率(与20-100公里相比，只有几公里)提供信息，并且能够考虑较小规模的大气环流，例如与对流雷暴有关的大气环流，产生更真实的降雨和洪水强度和频率(McGregor，1996；Rabb，2017)。UKCP18气候预测建立在UKCP09的基础上。UKCP18的分辨率甚至更高，提供了更复杂的气候预测，并在区域范围内提供了更详细的信息(Rabb等人，2017年)。RCM数据与水文学和水力模型一起，使人们能够更好地了解气候变化将如何影响径流、河流水文和洪水风险。尽管在气候建模方面取得了这些重大进展，但在以下方面仍然存在重大研究空白：这种提高分辨率的气候理解如何转化为洪灾影响，以及如何在现有的洪灾评估方法和模型中最好地利用这些新数据。该项目将专门解决这一研究差距。除了传统的防洪选择外，可持续城市排水系统(SODS)和最近的自然洪水管理(NFM)方法现在都被用作缓解选择，以应对日益增加的洪水风险。然而，考虑到真正的防洪方案的复杂性，如何在给定的城市集水区最好地利用这两种选择并不总是显而易见的。除了探索气候变化预测外，这个项目还将考察实际防洪计划中使用的一系列缓解方案，由合作伙伴提供工程级洪水模型。这个博士项目为学生提供了一个独特的机会来整合两个相互关联的研究领域，在尖端气候建模和洪水风险评估的界面上工作。CASE合作伙伴WSP(一家主要的工程咨询公司)和利兹市议会(当地主要防洪当局)的支持提供了与防洪专业人员合作并向他们学习的机会，同时最大限度地发挥了研究的影响。学生应该对与气象、气候和洪水风险相关的环境问题有浓厚的兴趣。他们还将在定量科学(数学、物理、工程、环境科学)方面拥有深厚的背景，并具有编程和科学计算的天赋，或非常熟悉编程和科学计算。学生将在Mark Trigg博士(洪水风险和NFM)、Christian Berretta博士(肥皂和排水)、凯瑟琳·伯奇博士(气候建模)、Paul Lambert(WSP，洪水与排水)和Matt Sherwood(LCC，洪水风险)的指导下工作。该学生将直接受益于利兹大学、WSP和利兹市议会之间现有的合作伙伴关系。将提供专门科目、专业洪水和排水模拟软件和方法方面的高级培训。

The frequency and impact of heavy rainfall associated with summer convective storms and winter frontal storms is projected to increase with future climate change. Higher intensity rainfall poses significant pluvial flooding challenges in urban areas, which have constrained mitigation options due to existing infrastructure and developments. Local authorities need to account for climate change in flood mitigation strategies and currently use regional climate models (RCM's) such as the UKCP09 climate projections issued by the Met Office (Rabb et al, 2017). These model simulations provide projections of how variables such as temperature, rainfall, and humidity may change at a regional level under climate change. RCMs have a number of advantages over more traditional Global Climate Models (GCMs); they provide information at a higher spatial resolution (a few kilometres compared to 20-100km) and they are able to account for smaller scale atmospheric circulations such as those associated with convective thunderstorms, producing more realistic rainfall and flood intensities and frequencies (McGregor, 1996; Rabb, 2017). The UKCP18 climate projections build on UKCP09. UKCP18 has an even finer resolution and provides more sophisticated climate projections, with greater detail at regional scales (Rabb et al, 2017). The RCM data, alongside hydrology and hydraulic modelling, enables an enhanced understanding of how climate change will impact streamflow, river hydrology and flood risk. Despite these significant advances in climate modelling, there are still major research gaps in terms of how this enhanced resolution climate understanding translates into flooding impacts, as well as how best to utilise this new data in existing flood assessment methodologies and models. This project will specifically address this research gap. Along with traditional flood defence options, sustainable urban drainage systems (SUDS), and more recently natural flood management (NFM) methodologies are all now being utilised as mitigation options to addressing increased flood risk. However, how best to utilise this combination of options in a given urban catchment is not always obvious, given the complexities of real flood defence schemes. As well exploring climate change projections, this project will also look at a range of mitigation options used in real flood defence schemes, with engineering grade flood models provided by partners.This PhD project provides a unique opportunity for a student to integrate two linked research areas, working at the interface of cutting edge climate modelling and flood risk assessment. The support of CASE partner WSP (a major engineering consultancy) and Leeds City Council (Lead local flood authority) provides the opportunity to work with and learn from flood defence professionals, while maximising the impact of the research. The student should have a strong interest in environmental problems related to meteorology, climate and flood risk. They will also have a strong background in a quantitative science (math, physics, engineering, environmental sciences) and a flair for, or a good familiarity with, programming and scientific computing.The student will work under the supervision of Dr Mark Trigg (Flood Risk and NFM), Dr Christian Berretta (SUDS and drainage), Dr Cathryn Birch (Climate modelling), Paul Lambert (WSP, Flooding & Drainage), and Matt Sherwood (LCC, Flood Risk). The student will benefit directly from an existing partnership between the University of Leeds, WSP and Leeds City Council. High level training will be provided in specialist subjects professional flood and drainage modelling software and methods.