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Summary There is a vital need for research that links meteorological drought indices with drought impacts felt on the ground. Previously, this link has been estimated based on experience or defined based on very narrow impact measures. This study expands on earlier work by showing the feasibility of relating user-provided impact reports with meteorological drought indices, the Standardized Precipitation Index and the Standardized Precipitation-Evapotranspiration Index, through logistic regression, while controlling for seasonal and interannual effects. Analysis includes four impact types, spanning agriculture, energy and industry, public water supply, and freshwater ecosystem across five European countries. Statistically significant climate indices are retained as predictors using step-wise regression and used to compare the most relevant drought indices and accumulation periods across different impact types and regions. Agricultural impacts are explained by 2–12 month anomalies, though anomalies greater than 3 months are likely related to agricultural management practices. Energy and industrial impacts, typically related to hydropower and energy cooling water, respond slower (6–12 months). Public water supply and freshwater ecosystem impacts are explained by a more complex combination of short (1–3 month) and seasonal (6–12 month) anomalies. The resulting drought impact models have both good model fit (pseudo- R 2 = 0.225–0.716) and predictive ability, highlighting the feasibility of using such models to predict drought impact likelihood based on meteorological drought indices. [ABSTRACT FROM AUTHOR]

Risk management has reduced vulnerability to floods and droughts globally 1,2 , yet their impacts are still increasing 3 . An improved understanding of the causes of changing impacts is therefore needed, but has been hampered by a lack of empirical data 4,5 . On the basis of a global dataset of 45 pairs of events that occurred within the same area, we show that risk management generally reduces the impacts of floods and droughts but faces difficulties in reducing the impacts of unprecedented events of a magnitude not previously experienced. If the second event was much more hazardous than the first, its impact was almost always higher. This is because management was not designed to deal with such extreme events: for example, they exceeded the design levels of levees and reservoirs. In two success stories, the impact of the second, more hazardous, event was lower, as a result of improved risk management governance and high investment in integrated management. The observed difficulty of managing unprecedented events is alarming, given that more extreme hydrological events are projected owing to climate change 3 ., (© 2022. The Author(s).)