The Enhanced Mitigation of Coastal Erosion Using the Artificial Coral Reefs

Abstract

The increase of the sea level, coastal development, and secondary damages caused by hard structures have threatened the coastal resilience recently. To cope with these problems, we introduced an alternative method using a soft structure of a ductile-type submerged breakwater named artificial coral reefs (ACRs). We performed two-dimensional hydraulic experiments to verify the reduction efficiency of the wave transmission rate compared with that of a natural seabed and tetrapod (TTP) structure. In particular, we carried out spectral analysis using the Joint Sea Wave Project (JONSWAP) energy spectrum to determine the peak value of the wave energy. We found that the transmission rate and peak value of the wave are 26.0% and 44.3%, respectively, under ordinary wave conditions, which suggests that ACRs cost-effectively have a suitable wave attenuation efficiency to replace TTP structure for recovering coastline. Finally, the results reveal that crown depth of the structure plays a key role in wave energy attenuation.