Speaker: Prof Onno Bokhove (British-Dutch mathematician/fluid dynamics analyst School of Mathematics, University of Leeds, Leeds, University of Leeds)
Title: Managing river floods in an age of extremes: should we be more worried?
Abstract:
I am an applied mathematician who began considering the science and policy of flooding after participating in a rescue operation in Leeds during the 2015 Boxing Day floods. That flood was of a magnitude expected only once in 200 plus years (on average). But what does ‘once in 200 plus years (on average)’ mean? To express the answer to this question visually, we designed the “Wetropolis flood demonstrator”.Wetropolis conceptualises the science of flooding in a way that assists the experience and visualisation of uncertainty, extreme rainfall and flooding. It is accessible to and directly engages the general public, and it is showcased here at the MPE exhibition.Over the last few years, citizens’ flood-action groups have called me in to provide advice and explain the science of flooding and extremes; this can be a challenging task, and being able to showcase Wetropolis live has been a great help in that regard. Motivated by Wetropolis and the 2015 Boxing Day floods, we created a graphical cost-effectiveness analysis to assess and communicate various flood-mitigation options in a way that would be understandable for both members of the public and decision-makers.Numerous severe (river) flooding events have occurred in the UK over the last two decades. In addition to showing how the Wetropolis flood demonstrator works, I will be addressing various questions that recent flooding events have made more pressing:- Will it really rain more in the future, especially due to climate change?
- How well do we predict precipitation and flooding?
- Can we define extreme precipitation and flooding events? What is a return period?
- How well can we predict precipitation and flooding?
- Just how good are things like beaver dams, natural flood management, and flood-plain storage, at mitigating floods?
- If we aren’t sure, how can we test and discuss the effectiveness of flood-mitigation measures?
- Finally, are we worried enough about future extreme flooding events?