A new collaborative study led by researchers at the National Institute for Environmental Studies, the University of Tokyo, and Michigan State University exposes the role of dams for mitigating flood risk under climate change.
A new collaborative study led by researchers at the National Institute for Environmental Studies, the University of Tokyo, and Michigan State University exposes the role of dams for mitigating flood risk under climate change.
Flood is amongst the costliest natural disasters. Globally, flood risk is projected to increase in the future, driven by climate change and population growth. The role of dams in flood mitigation, previously unaccounted for, was found to decrease by approximately 15% the number of people globally exposed to historical once-in-100-year floods, downstream of dams during the 21st century.
Currently, about half of major river systems worldwide are regulated by dams and more than 3,700 major dams are planned or under construction. Consequently, to realistically assess population exposure to present and future floods, current and future dam landscapes must be integrated into existing flood modeling frameworks.
Accounting for dams in river flood simulations, the number of people exposed to the historical once-in-100-year flood below dams were 7.2 and 13.4 million on average over 2006–2099 given a low and a medium-high greenhouse gas emission trajectory (RCP2.6 and RCP6.0, respectively). The populations exposed to flooding below dams decreased on average by 16.3% and 12.8% for the two trajectories compared to simulations not accounting for the flow regulations produced by dams. At the end of the 21st century, the decrease was further extended to 20.6% and 12.9% respectively.
Read more at National Institute for Environmental Studies
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