Spatial dike breach: Accuracy of photogrammetric measurement system

Dikes along rivers prevent flooding of the adjacent environment during floods. Many dikes were not improved during decades so that overtopping has caused large damages to populated and agricultural areas. The spatial dike breach process due to overtopping is still poorly understood despite recent advances. Therefore, novel laboratory experimentation is tested to evaluate its main features. The original stereo-photogrammetric AICON measurement system was adapted to account for refraction effects of a quasi-horizontal water surface for recording river bed elevations in physical models. The system was complemented at VAW with a fourth camera to record the flow depth along the channel side wall. For overtopping scenarios, modifications have been implemented, resulting in a significant improvement of the set-up. First dry and submerged conditions and a plane dike breach are investigated. Then, the flow over a fixed spatial dike breach is studied with a focus on the effect of surface waves on the results.