Current and future risks of unprecedented UK droughts

• DOI: 10.5194/egusphere-egu22-704
• Publication Date: 2022-03-26T13:52:17Z
• Authors: Wilson Chan; Theodore Shepherd; Katie Facer-Childs; Geoff Darch; Nigel Arnell; Karin van der Wiel
• Keywords: 13. Climate action; 15. Life on land; 6. Clean water

<p>The UK has experienced recurring periods of hydrological droughts in the past and their frequency severity are predicted to increase with climate change. However, quantifying risks extreme is challenging given short observational record, multivariate nature large internal variability system. We use EC-Earth time-slice ensembles, which consist 2000 years data each for present day, 2°C 3°C conditions, drive GR6J model at river catchments obtain a set plausible droughts. Applying UNSEEN (UNprecedented Simulation Extreme Events using ENsembles) approach show an increasing chance unprecedented dry summers future warming highlight drought characteristics exceeding that severe droughts.</p><p>This study also aims bridge probabilistic “bottom-up” storyline approaches. Physical storylines preconditioned compound events created by searching within ensemble resembling specific conditions have led relevant water resources planning. This includes such as 1) autumns followed winters, 2) consecutive winters (both slow-responding catchments), 3) springs (relevant fast-responding catchments). The can be used understand leading impacts triggered same conditions. Unprecedented sequences synthetic experiments conditioned on these stress-test systems inform decision-making.</p>