Random wave runup at a plane beach

Accurate estimation of irregular wave runup at sloping beaches is important in assessments of coastal erosion and flood risk. We define runup as the vertical elevation of the shoreline position, driven by swash oscillations about the wave setup level. To date there have been rather few investigations into irregular wave runup statistics, and these have assumed linear, Gaussian behaviour. This presentation will describe use of a 1-D hybrid Boussinesq-NLSW model to produce statistical information on the runup of irregular waves, arising from a random sea state offshore of the beach. A validated technique will be presented for simulating long-duration irregular runup time series whereby the incident waves are generated using second-order accurate paddle motions with reflected waves effectively absorbed before they reach the paddle.