The influence of different check dam configurations on the downstream river topography and water–sediment relationship

Abstract

This study investigates the impact of various check dam configurations on the downstream river channel morphology and water–sediment relationships through the big indoor simulation experiments as 31.5 m long and 16.5 m wide. The findings demonstrate that the construction of check dams effectively regulates the erosion and sedimentation processes of the river channel. When compared to the no-dam scenario, the flow rates decreased by 43 %-69 % across the three dam configurations, while sediment concentrations reduced by 45 %-86 %. The construction of dams notably altered both the cross-sectional shape and micro-topography of the river channel. Specifically, the dual-dam configuration led to a 41.35 % decrease in slope and a 30.74 % reduction in roughness. Interestingly, the reduction in slope and roughness were more significant in the dual-dam configuration than in the sum of the changes caused by two individual dams. Additionally, a random forest algorithm was applied to rank the importance of various parameters influencing sediment concentration and particle size. Key factors such as runoff shear stress, roughness, runoff power, and slope were identified as having the greatest impact. These findings provide valuable theoretical and technical insights for the optimization design and management of check dams in the Loess Plateau region.