Exploring drought‐to‐flood interactions and dynamics: A global case review

Abstract

This study synthesizes the current understanding of the hydrological, impact, and adaptation processes underlying drought‐to‐flood events (i.e., consecutive drought and flood events), and how they interact. Based on an analysis of literature and a global assessment of historic cases, we show how drought can affect flood risk and assess under which circumstances drought‐to‐flood interactions can lead to increased or decreased risk. We make a distinction between hydrological, socio‐economic and adaptation processes. Hydrological processes include storage and runoff processes, which both seem to mostly play a role when the drought is a multiyear event and when the flood occurs during the drought. However, which process is dominant when and where, and how this is influenced by human intervention needs further research. Processes related to socio‐economic impacts have been studied less than hydrological processes, but in general, changes in vulnerability seem to play an important role in increasing or decreasing drought‐to‐flood impacts. Additionally, there is evidence of increased water quality problems due to drought‐to‐flood events, when compared to drought or flood events by themselves. Adaptation affects both hydrological (e.g., through groundwater extraction) or socio‐economic (e.g., influencing vulnerability) processes. There are many examples of adaptation, but there is limited evidence of when and where certain processes occur and why. Overall, research on drought‐to‐flood events is scarce. To increase our understanding of drought‐to‐flood events we need more comprehensive studies on the underlying hydrological, socio‐economic, and adaptation processes and their interactions, as well as the circumstances that lead to the dominance of certain processes.This article is categorized under: Science of Water > Hydrological Processes Science of Water > Water Extremes

Compound and consecutive drought-flood events at a global scale

“…Consecutive and compound drought-flood events are greatly understudied and drought influence on flood dynamics remains mostly unknown (Barendrecht et al 2024). Recent studies on consecutive events have investigated dry-to-wet events regionally (Fang et al 2019, Shi et al 2020, Zhao et al 2020 and globally (He and Sheffield 2020, Rashid and Wahl 2022), using standardized indices of precipitation and evapotranspiration (e.g.…”

Hydrological Drought‐To‐Flood Transitions Across Different Hydroclimates in the United States

“…While the impact of reservoir regulation on individual drought and flood events is undisputed, it is yet unclear how such regulation affects the transition from droughts to floods. Drought-to-flood transitions can be harmful events, where the extreme events may amplify each other's impact (Barendrecht et al, 2024). For example, flood protection measures can be weakened by the occurrence of a drought, for example, due to an increased risk of dike failure or a decreased infiltration capacity of soils (Ward et al, 2020).…”

“…Droughts and floods have severe impacts on society, economy, and ecosystems (e.g., Cammaleri et al, 2020;Hammond et al, 2015;Jones & Van Vliet, 2018;Mosley, 2015;Tradowsky et al, 2023), which can be particularly pronounced if they occur in close succession, that is, when droughts rapidly transition to floods (Barendrecht et al, 2024;Ward et al, 2020). The negative impacts of drought-to-flood transition events are illustrated by recent examples such as the floods in winter 2016-2017 following on the multi-year drought of 2011-2016 in California (He & Sheffield, 2020;Swain et al, 2018), the drought-to-flood transition in Kenya in 2017-2018 which led to a humanitarian crisis (Matanó et al, 2022), and the May flood in 2023 in the Italian region Emilia-Romagna which followed on a prolonged dry period (Povoledo, 2023).…”