Numerical investigation of the influence of the enhancement of cyclones on long-term shoreline movement

Kuriyama, Y. and Banno, M.., 2013. Numerical investigation of the influence of the enhancement of cyclones on long-term shoreline movement

The enhancement of tropical and extratropical cyclones caused by global warming is expected to induce morphological changes in the nearshore zone. Hence, the influence of the increase in offshore wave energy flux E_f due to the enhancement of cyclones on long-term shoreline movement on the Hasaki coast of Japan was examined using a numerical model for predicting the shoreline changes caused by cross-shore sediment transport. The shoreline movements during a 100-year period were predicted with 4-month intervals by increasing the means and/or standard deviations of E_f during the 4-month seasons. Under each wave condition, the predictions were implemented 1000 times with E_f estimated using a Monte Carlo method. The prediction results showed that the shoreline retreated 18 m with 20% increases and 33 m with 50% increases in both the means and standard deviations of E_f in the 100–year period. The increases in both the means and standard deviations of E_f during the periods from May to August and from January to April influenced the shoreline retreat most and least, respectively. This was probably due to the nonlinear relationship between the shoreline change rate and E_f.