Erosion of sand at high flow velocities: An experimental study

The safety level of a dike is expressed in terms of risk. Risk is defined as the product of the probability of inundation of a polder (after failure of a dike) and the expected damage (casualties, economic damage and damage to the infrastructure) caused by inundation. The rate of inundation determines the amount of casualties and depends heavily on the flow velocity through the breach and breach development in time. The flow velocity in a breach can become larger than 5 m/s. Due to these large flow velocities, the application of conventional sediment pick-up functions in breach growth models, leads to a significant overestimation of the breach growth and thus the rate of inundation.