Modeling dike erosion due to overtopping flow with a vertically-averaged non-hydrostatic and non-equilibrium sediment transport model

F.N. Cantero-Chinchilla and O. Castro-Orgaz

Earthen dikes are economical, manmade river restoration and protection structures widely use to prevent human, economic and environmental disasters triggered by floods. The action of the climate change is greatly exacerbating the frequency and intensity of extreme weather events like torrential storms, which are common in mediterranean areas such as DANAs in the east coast of the Iberian Peninsula, thus increasing the risk of suffering floods consequences derived from failures of hydraulic structures like the earthen dikes. The study of earthen dike overtopping failure is, therefore, relevant for the society. Among the plethora of failure mechanisms in earthen dikes, the erosion due overtopping flow is one of the most common phenomena, which leads to important sediment transport rates along the dike surface, ultimately provoking the wash-off of the dike body material. Physically, during the overtopping flow the dike crest becomes rounded, producing a significant vertical acceleration which impacts the sediment transport down the crest domain. Attempts to understand these phenomena through hydrodynamic simulations were conducted at the University of Córdoba using a vertically-averaged non-hydrostatic and non-equilibrium sediment transport model. These investigations are presented here, and the scope of future research discussed.