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

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.