Plane dike-breach due to overtopping: effects of sediment, dike height and discharge

Due to increased flood discharges during the past years, overtopping of dikes and earthen embankments has caused large damages to the surrounding infrastructure and the environment. Despite the numerous dike breaches and the high damage potential, the dike-breach process is still only poorly understood. Therefore, hydraulic model tests were conducted to investigate the main features of the plane dike-breach due to overtopping. The temporal dike-breach progress was optically recorded allowing for a detailed analysis of the sediment and water surfaces. The results indicate a decisive effect of the sediment diameter on the breach process. A systematic variation of the dike dimension, the sediment diameter and the inflow discharge resulted in basic findings relative to the breach discharge and the dike degradation. The governing parameters of this dike-breach process include the dike height, the grain size and the critical flow depth.