Influences of beach berm height on beach response to storms: A numerical study: Fid-Bau Portal

Influences of beach berm height on beach response to storms: A numerical study

Zhu, Jun / Shi, Fengyan / Cai, Feng / Wang, Qing / Qi, Hongshuai / Zhan, Chao / Liu, Jianhui / Liu, Gen / Lei, Gang

Abstract The field observation at two neighboring beaches showed significant effects of berm height on beach profile changes during a major storm. The fully nonlinear Boussinesq wave model, FUNWAVE-TVD, with a sediment transport module was used to simulate the beach erosion processes of the two beaches. The model reproduced the beach profile changes in good agreement with the measured data. The model results revealed that, for the beach with a higher berm, the wave force, wave-induced undertow flow, along with the higher sediment concentration on the berm induce more offshore sediment transport and cause significant beach profile changes compared to the beach with a lower berm. The erosion trend with different berm heights was predicted by using a series of numerical tests with different berm heights and offshore forcing conditions. The test results suggested that beach erosion increases with the berm height until the berm height reaches a certain level.

Highlights • Field observation erosion/deposition shows pattern different storm-induced between two neighboring beaches. • The sediment module in the Boussinesq model, FUNWAVETVD, is validated against measured morphological data for the first time for the wind wave conditions. • Trend of beach erosion with different heights of beach berm is investigated.