THE EFFECTS OF WAVE CHRONOLOGY ON MEDIUM AND LONG-TERM COASTAL MORPHOLOGY

The sequencing, or chronology, of wave events plays an important role in determining how coastlines and nearshore regions evolve over medium and long timescales (from weeks to decades). However, present-day com puter models of coastal morphology treat the input wave conditions in either a deterministic (i.e. a single wave sequence) or a probabilisti c manner. In neither method are the effects of the full range of possi ble future wave sequences, for given overall statistical values, calcu lated. The methodology presented here addresses this problem by multip le model runs using different re-orderings of a wave sequence. A serie s of tests demonstrate different aspects of wave chronology and its im portance in the prediction of seabed and beach levels. The method prov ides a means both for understanding wave chronology effects and for pr edicting these effects in practical engineering problems involving med ium and long timescale changes to coastal morphology.