Wave Attenuation Analysis for Artificial Coral Reefs Using a Physical Modelling Approach

Abstract

Kim, T.; Kwon, Y.; Hong, S.; Kim, J.; Kwon, S., and Lee, J., 2021. Wave attenuation analysis for artificial coral reefs using a physical modelling approach. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 529–533. Coconut Creek (Florida), ISSN 0749-0208. Due to global warming and coastal development, the damages in coastal such as sea level rise and changes in coastline caused by scour and erosion are increasing, Various types of breakwaters are applied to prevent the coastal erosion, however, the problem such as scour around the structure is exacerbated, therefore a fundamental solution is needed. In this study, two-dimensional laboratory experiments were conducted in the wave flume to investigate the wave transmission phenomena of artificial coral reef. Experiments are conducted by analyzing wave transmission dependents on ratio of stem length to water depth(ls/h), wave height and wave period. Wave attenuation appeared to be most dependent on stem length to water depth(ls/h) and structure width. As incident wave height increased and the wave period decreased, the wave attenuation also increased, however, it was insignificant compared to the influence of the inundation rate. Wave attenuation increases dependents on incident wave height and period, however showed insignificant effect compared to submergence rate. In addition wave attenuation rate also affects wave energy reduction in order of ls/h > H0/h > h/L0. Based on results, we analyzed correlation between KC and CD of artificial coral reef to suggest the equation on empirical relationship. As a result, it is judged that estimating wave transmission rate and drag coefficient of artificial coral reef dependents on sectional specification can be utilized properly in working design and application.