Fluvial Dike breach evolution by overtopping. an analysis of hydrodynamic and morphodynamic experimental data 

Ricardo JÓNATAS, Francisco GOUVEIA, Sílvia AMARAL, Rui ALEIXO, Teresa VISEU, Rui FERREIRA

The safety and reliability of flood protection such as fluvial dikes are critical for reducing the risks of flooding to human settlements and infrastructure. Dike’s simple structure nature exposes them to failures like overtopping or piping, which can be severe by the increasing of extreme climatic events. While previous studies have explored the mechanics of dike breaching due to overtopping, including empirical data and modeling, there is a gap in understanding dike breach evolution under constant main channel load (simulated river) conditions, particularly concerning the role of controlled embankment water content and upstream hydraulic conditions. This paper addresses this gap by presenting experimental data from two test sets conducted under a constant main channel load. In the first set, the upstream hydraulic conditions were kept constant while the embankment water content was varied. In the second set, the embankment water content was fixed, and upstream hydraulic conditions were changed. This dual approach enables a comprehensive analysis of how these factors influence the dike breach evolution. The results provided valuable data to enhance the knowledge on hydrodynamic and morphodynamic processes of fluvial dike breaches and will later be applied in mathematical models to improve safety strategies during overtopping events.