Future hot-spots for hydro-hazards in Great Britain: a probabilistic assessment

TLDR

Climate change is increasing hydro‑climatic risk across Great Britain. The study aims to identify future hydro‑hazard hot‑spots across Great Britain due to climate change. Flood and drought hazards were defined with a threshold method, and a nationwide statistical framework quantified changes in frequency, magnitude, duration, and timing between 1961–1990 and 2069–2098 using the Future Flows Hydrology database. Hydro‑hazard hot‑spots are projected to develop along the western coast of England and Wales and north‑eastern Scotland, mainly in winter floods and autumn droughts, with drought hazards increasing more in magnitude and duration. Abstract.

Abstract

Abstract. In an increasing hydro-climatic risk context as a result of climate change, this work aims to identify future hydro-hazard hot-spots as a result of climate change across Great Britain. First, flood and drought hazards were defined and selected in a consistent and parallel approach with a threshold method. Then, a nation-wide systematic and robust statistical framework was developed to quantify changes in frequency, magnitude, and duration, and assess time of year for both droughts and floods, and the uncertainty associated with climate model projections. This approach was applied to a spatially coherent statistical database of daily river flows (Future Flows Hydrology) across Great Britain to assess changes between the baseline (1961–1990) and the 2080s (2069–2098). The results showed that hydro-hazard hot-spots are likely to develop along the western coast of England and Wales and across north-eastern Scotland, mainly during the winter (floods) and autumn (droughts) seasons, with a higher increase in drought hazard in terms of magnitude and duration. These results suggest a need for adapting water management policies in light of climate change impact, not only on the magnitude, but also on the timing of hydro-hazard events, and future policy should account for both extremes together, alongside their potential future evolution.