Hybrid one-line/ 2DH model of submerged breakwater for coastal protection

Submerged breakwaters, like natural reefs, have the potential to promote the resilience of beaches by creating a buffer against waves and generating circulation patterns that retain sand. However, the shoreline response of these structures' interaction with coastal dynamics are not fully understood and can lead to beach erosion if designed poorly. A one-line shoreline model was combined with a coupled wave, flow, and sediment model to provide an efficient, fast, and robust framework utilising the long-term stability advantages of the one-line model and the detailed cell-centred morphohydrodynamic calculations of the coupled model, which describes the forces around the submerged breakwater. The model is capable in simulating circulation patterns and erosion/accretion patterns qualitatively in line with literature and exhibits the expected response across the tested parameters. This model allows for future studies to focus on site-specific modelling of submerged breakwaters and quickly testing various environmental and design parameters.