Globally,between 1950 and 2011 nearly 80,000 debris flow fatalities occurred in densely populated regions in mountainous terrain.Mitigation of these hazards includes the construction of check dams,which limit coarse sediment transport and in the European Alps number in the 100,000s.Check dam functionality depends on periodic,costly maintenance,but maintenance is not always possible and check dams often fail.As such,there is a need to quantify the long-term(10-100 years)geomorphic response of rivers to check dam failures.Here,for the first time,a landscape evolution model(CAESAR-Lisflood)driven by a weather generator is used to replicate check dam failures due to the lack of maintenance,check dam age,and flood occurrence.The model is applied to the Guerbe River,Switzerland,a pre-Alpine catchment containing 73 check dams that undergo simulated failure.Also presented is a novel method to calibrate CAESAR-Lisflood's hydrological component on this ungauged catchment.Using 100-year scenarios of check dam failure,the model indicates that check dam failures can produce 8 m of channel erosion and a 322％increase in sediment yield.The model suggests that after check dam failure,channel erosion is the remobilization of deposits accumulated behind check dams,and,after a single check dam failure channel equilibrium occurs in five years,but after many check dam failures channel equilibrium may not occur until 15 years.Overall,these findings support the continued maintenance of check dams.

Jorge Alberto Ramirez;Mirjam Mertin;Nadav Peleg;Pascal Horton;Chris Skinner;Markus Zimmermann;Margreth Keiler

Institute of Geography,University of Bern,Bern,Switzerland;Oeschger Centre for Climate Change Research,University of Bern,Bern,Switzerland;Institute of Environmental Engineering,ETH Zurich,Zurich,Switzerland;Institute of Earth Surface Dynamics,University of Lausanne,Lausanne,Switzerland;Energy and Environment Institute,University of Hull,Hull,United Kingdom;Department of Geography,University of Innsbruck,Innsbruck,Austria;Institute for Interdisciplinary Mountain Research,Austrian Academy of Sciences,Innsbruck,Austria

国际泥沙研究（英文版）

[1]Jorge Alberto Ramirez;Mirjam Mertin;Nadav Peleg;Pascal Horton;Chris Skinner;Markus Zimmermann;Margreth Keiler-.Modelling the long-term geomorphic response to check dam failures in an alpine channel with CAESAR-Lisflood)[J].国际泥沙研究（英文版）,2022(05):687-700

Lisflood,Guerbe,ungauged

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