Didenkulova, I., Denissenko, P., Rodin, A. and Pelinovsky, E., 2013. Effect of asymmetry of incident wave on the maximum runup height.

Shoaling and runup of long waves on a beach form a classical task for coastal oceanography and engineering. Though many empirical and theoretical formulae have been developed in this field, most of them are targeted to typical waves and situations, while the greatest hazard is caused by extreme events, such as, for example, extreme storms and catastrophic tsunamis. From this point of view it was shown theoretically that one of the most important parameters which influence the wave runup height is the steepness of the incident wave front and the asymmetry of the incident wave. It helped to provide a simple explanation to the extreme runup observed during the catastrophic 2004 Indonesian tsunami event. However, the theoretical results were obtained under many assumptions (ideal fluid, no wave breaking, no bottom friction) and have not been validated. Here we present an experimental study performed in the Large Wave Flume (GWK), Hannover, Germany, which is focused on the influence of the asymmetry caused by the non-linear deformation of incident waves on their runup on a plane beach. The series of experiments are aimed to validate the theoretical formulae for runup height of asymmetric waves. Obtained results are in a good agreement with theoretical predictions and corresponding formulae are recommended to be considered in wave forecasts.