Dam-break induced morphological changes in a channel with uniform sediments: measurements by a laser-sheet imaging technique

Soares Frazao, Sandra [UCL] Le Grelle, N. Spinewine, Benoît [UCL] Zech, Yves [UCL]

This paper presents an idealised experiment of dam-break flow in a channel where both the bed and the banks are made of uniform erodible material. The aim is to study the morphological changes induced by a dam-break flow, as well in the bed profile (longitudinal erosion) as in the shape of the cross sections (lateral erosion and bank failures). The experiments show good qualitative agreement with field observations of geomorphic flows, and have the advantage that they are repeatable for what concerns the general evolution of the shape of the cross sections. A non-intrusive laser sheet technique was used to measure the shape of the cross sections. From there, a complete survey of the time evolution of the channel shape could be obtained. This survey forms a data set that can be used for the validation of numerical models.