Scour downstream of stepped-baffle weirs in wide rivers

In this study, the effect of the structure geometry, the bed material, and the river hydraulic conditions on the scour morphology downstream of the stepped-baffle weirs are experimentally investigated. All experiments are conducted in clear water conditions (no sediment transport). Results show, that in the presence of stepped-baffle weirs, the maximum scour depth diminishes with respect to the simple stepped weirs (no baffle) highlighting that increasing the tailwater depth, decreases the maximum scour depth, and decreasing the structure slope, decreases the maximum scour depth. By means of dimensional analysis and incomplete self-similarity, a formula is proposed to predict the maximum scour depth downstream of a stepped-baffle weir considering all aspect ratios of the structure geometry.