Sandy beach profile response to different artificial nourishment strategies: Insights from physical model experiments

Beach nourishment, as a "soft" engineering approach, has gained increasingly popularity for its eco-friendly, cost-effective, and sustainable erosion control mechanisms. To optimize beach protection and ecological restoration, understanding the effects of different nourishment schemes on wave dynamics and morphological evolution is essential. Through controlled flume experiments under regular waves, this study compares sandbar nourishment and berm nourishment. The results show significant changes in wave skewness and asymmetry, driven by nonlinear dynamics under higher waves and longer periods. Sandbar nourishment induces shoreward bar migration and trough infilling, while berm nourishment causes offshore sediment transport and shoreline retreat. Stage-dependent sediment transport and distinct erosion patterns were observed. A formula for the beach profile morphology under the berm nourishment scheme is proposed, offering practical insights for selecting effective nourishment strategies. These findings provide scientific guidance for designing and implementing sustainable beach restoration projects to advance coastal protection efforts.