Irregular Wave Runup on Beaches

(HQUSACE) elements and field operating activities having Civil Works design responsibility. BACKGROUND: The estimation of wave runup on natural beaches is important to the design of artificial fill beaches as well as to estimation of flood structural damages on existing beaches for “as-is ” project conditions. Existing design practice estimation of wave runup in many countries relies on measurement of offshore wave climate at a site and input of such wave climate into a non-distorted physical model. Output water level time series on a beach are then projected from measured water levels in the physical model. At present, the physics of wave runup on beaches is not understood and therefore cannot be numerically modeled. Empirical guidance is utilized for preliminary project estimation of gross wave runup statistics where physical modeling cannot be achieved due to time or money constraints. It should be recognized that present empirical guidance must only be util?zed as preliminary guidance due to the limited nature of existing data and the wide scatter provided by such data. For proper design where project design affects either lives and/or property values, laboratory testing is still necessary to assess damage levels due to wave runup and consequent wave overtopping. DISCUSSION OF THEORETICAL ASPECTS OF WAVE RUNUP: Wave runup is the dynamic elevation of the water level above still-water level due to wave action. Wave runup on a beach for laboratory monochromatic waves is typically defined as the maxima of the dynamic excursion of the water level on a sloping beach (see Figure 1) and consists of two parts, (1) wave setup, which is