Understanding Record Breaking Flood Events

Supervisors: Colin Manning (NU), Hayley Fowler (NU), Paul Young (JBA)

Contact email: Colin.Manning@newcastle.ac.uk

Location: Newcastle

Project Rational: The number of record-breaking flood events globally in recent years and the associated impacts is alarming. The European floods of 2021 had the highest river levels since records began and yielded US$54 billion worth of losses in damages (Tradowsky et al., 2023). The estimated return period for this event (400 years) has substantial uncertainty (95% CI: 250-2,500 years) which can hugely vary depending on data and methodology used. Accurate estimates are hindered by short observational records while model-based approaches (e.g. UNSEEN) that simulate large event sets do not accurately represent relevant processes that contribute to such extremes. Hence, estimating the changing risk of such events and choosing design levels for flood defenses is very challenging.

We propose to develop a process-driven view of risk estimations that invokes a bottom-up approach in which will start with a specified flood level (e.g. flood barrier). Our main research question will be: 'what rainfall volume is needed to exceed a given flood level and what combination of conditions could produce this level? This will aim to envision what such event might look like and identify the main contributing factors, the plausibility of their co-occurrences, and their projected changes in climate simulations.

Methodology: The PhD project will be divided in three parts. Following Fisher et al. (2021), the student will first assess observations to identify record breaking extremes (globally or regionally) that lay far outside the observational record before their occurrence (i.e. events with large risk estimate uncertainties). The student will identify the drivers of these events and potential common factors that contributed to their extremeness.

Secondly, the student will gain a quantitative understanding of the dependence of these factors within observations and climate simulations to gain a quantitative understanding of the likelihood of co-occurring extreme drivers. The student will assess large-ensemble simulations from high-resolution (e.g. UKCP18 Local) and courser resolution climate models (e.g. UKCP18 Global, UNSEEN) to understand if models can produce various aspects of these events (e.g. drivers and observed dependencies). The student will also assess future changes in the drivers and their co-occurrence.

Finally, the student will use this information to produce a qualitative tool through storylines (Shepherd, 2019) using physical plausibility to communicate the factors required for very extreme events (e.g. 1000-year events). This will be demonstrated as a complementary tool to conventional risk estimation methods where they struggle to provide accurate estimates, particularly in a future warmer climate.

Background Reading:
Tradowsky, J.S., Philip, S.Y., Kreienkamp, F., Kew, S.F., Lorenz, P., Arrighi, J., Bettmann, T., Caluwaerts, S., Chan, S.C., De Cruz, L. and de Vries, H., 2023. Attribution of the heavy rainfall events leading to severe flooding in Western Europe during July 2021. Climatic Change, 176(7), p.90.

Fischer, E.M., Sippel, S. and Knutti, R., 2021. Increasing probability of record-shattering climate extremes. Nature Climate Change, 11(8), pp.689-695.

Shepherd, T.G., 2019. Storyline approach to the construction of regional climate change information. Proceedings of the Royal Society A, 475(2225), p.20190013.

FLOOD-CDT
This PhD is being advertised as part of the Centre for Doctoral Training for Resilient Flood Futures (FLOOD-CDT). Further details about FLOOD-CDT can be seen here https://flood-cdt.ac.uk. Please note, that your application will be assessed upon: (1) Motivation and Career Aspirations; (2) Potential & Intellectual Excellence; (3) Suitability for specific project and (4) Fit to FLOOD-CDT. So please familiarise yourselves with FLOOD-CDT before applying. During the application process candidates will need to upload:
• a 1 page statement of your research interests in flooding and FLOOD-CDT and your rationale for your choice of project;
• a curriculum vitae giving details of your academic record and stating your research interests;
• name two current academic referees together with an institutional email addresses; on submission of your online application your referees will be automatically emailed requesting they send a reference to us directly by email;
• academic transcripts and degree certificates (translated if not in English) - if you have completed both a BSc & an MSc, we require both; and
• a IELTS/TOEFL certificate, if applicable.
Please upload all documents in PDF format. You are encouraged to contact potential supervisors by email to discuss project-specific aspects of the proposed prior to submitting your application. If you have any general questions please contact floodcdt@soton.ac.uk.

Apply
Apply for this PhD here: https://www.ncl.ac.uk/postgraduate/fees-funding/search-funding/?code=FLO...

Location: 
Newcastle

d96b37e25c18f40a