Improved Coastal Erosion Prevention Using a Hybrid Method with an Artificial Coral Reef: Large-Scale 3D Hydraulic Experiment

Abstract

Coastal erosion, a worldwide social issue, has garnered substantial attention. Numerous methods have been implemented to control coastal erosion problems; however, the presence of rigid structures limits erosion mitigation, thereby causing various challenges. For instance, in the case of submerged breakwaters, local scour in front of the structure and scour caused by the flow occurring in open inlets affect the subsidence and stability of the structure and can also cause structural failure. To solve these problems, this paper proposes a hybrid method of using a submerged breakwater with an artificial coral reef installation; further, this study evaluates the attenuation of waves and mitigation of sediment transportation through large-scale 3D hydraulic experiments. We found that the hybrid method with an artificial coral reef installed in the open inlet shows excellent wave control and plays a clearly beneficial role in the advancement of the shoreline. The artificial coral reef method reduced the return flow generated by the drag force at the breakwater shoulder and open inlet. In addition, scour at the breakwater shoulder was inhibited by collecting the sand escaping offshore. Simultaneously, scour at the open inlet was also mitigated. The application of the hybrid method compensated for the problems caused by local scour and erosion in the submerged breakwater, thereby leading to the improvement of its function. Therefore, the hybrid method proposed in this paper was determined to be applicable not only for submerged breakwaters, but also for various structures for controlling coastal erosion.

Analysis of Shoreline Change Due to the Installation of Hybrid Coastal Structure with Submerged Aquatic Vegetation (SAV)

“…To verify the N-line and 3D wave field models used in this study, a numerical tank was constructed based on existing hydraulic model experiments (Kim et al, 2020). The changes in shoreline and wave height around and behind the SB due to regular wave action were compared.…”

Review of Structure Types and New Development Prospects of Artificial Reefs in China

“…The relationship between the hydrodynamic characteristics and the ecological environment construction of artificial reefs is still unclear. With the severe erosion of the global coastline and the shortage of renewable energy, some researchers began to combine artificial reefs with the underwater breakwaters, the wave-dissipating structures, and the renewable energy devices (Srisuwan and Rattanamanee, 2015;De Almeida, 2017;Jiao et al, 2017;Kim et al, 2020;Ghiasian et al, 2021;Marin-Diaz et al, 2021). These multi-functional artificial reefs can not only fulfill the functions of ocean structures, but also enrich the diversity of marine organism.…”

Environmental impact of submerged and emerged breakwaters

“…(2018) created tidepools, which are unique intertidal habitats that favor breeding and feeding as well as providing shelter to a certain group of species, on artificial substrates in an attempt to mitigate the negative effects of artificial substrates on marine biodiversity. Kim et al. (2020) combined a submerged breakwater with an artificial reef installation to compensate for the stability problem caused by local scour.…”