While floods are among the most damaging natural hazards, they have helped shape human
developments over the last millennia, fostering scientific understanding and technological
advances in an attempt for their mitigation. We now more skilfully predict floods at
increasing lead times, through probabilistic hydro-meteorological forecasting. But we are
now facing new challenges.
Have we reached the limits of predictability with seasonal streamflow forecasting? This
thesis contributed to the implementation and design of operational seasonal streamflow
outlooks, as part of the European and the Global Flood Awareness Systems. Openly
available, they give users an overview of potential streamflow changes on sub-seasonal to
seasonal timescales. The analysis of both systems highlighted current limits in seasonal
predictability and the importance of initial hydrological conditions and the land surface
memory. To tackle these limits of predictability, a sensitivity analysis was developed to
guide developments for tangible future seasonal streamflow forecast improvements.
Are technical and scientific advances increasing faster than the rate at which forecasts are
usable for decision-making? As shown by the application of serious games and research
interviews at the Environment Agency (to guide a successful transition to probabilistic
forecasts for flood early warning in England), science (e.g. forecast skill) is not necessarily
a limiting factor for decision-making. Improved communication between scientists and
decision-makers, aimed for instance at understanding the complex landscape in which
decision-makers operate, is key to a successful adoption of the latest science in practice. Art
can help bridge the communication gap, and this thesis culminated in an art exhibition,
‘Gambling with floods?’, at The Museum of English Rural Life (Reading, UK) from 1 to 15
November 2019, created to reach a wide audience.
Overall, this thesis has shown that a closer interaction between decision-makers, scientists
and artists is urgently needed for a co-leadership on improving science for society
