Climate change impact on short-duration extreme precipitation and intensity-duration-frequency curves over Europe

To build future climate-proof water systems and to reduce the failure risk of infrastructure, short-duration extreme precipitation design storms must be updated. However, a robust future projection of such storms on a continental scale has not been presented due to the scarcity of long, high quality sub-daily data both for observations and model simulations. To address this need, we develop current and future precipitation intensity-duration-frequency (IDF) curves for Europe for 0.5-, 1-, 3-, 6-, 12- and 24-hour durations and for different return periods ranging between 1 and 100 years derived from a Generalized Pareto Distribution (GPD). Future IDF curves are developed in the framework of the quantile perturbation downscaling method by applying climate change signals from the EURO-CORDEX RCMs on current IDF curves obtained from high-resolution remote sensing based products. Here we show that rarer sub-daily extreme precipitation events will intensify more than less rare events and that changes may depend on precipitation duration. The frequency of sub-daily extreme precipitation events of 50- and 100-year return periods will be tripled under the high-end RCP8.5 scenario. Such intensification will lead to a substantial uplift (16-27% depending on duration and return period) and steepening (17-25% depending on return period) of the IDF curves under future climate change, calling attention to the vulnerability of the existing water infrastructure systems.