Mitigation of Beach Erosion after Coastal Road Construction

Beach erosion problems have become prevalent in Korea as a result of its economic growth and coastal development. This paper summarizes a comprehensive approach used to mitigate beach erosion that occurred after the construction of a coastal road with a seawall along Namae Beach in Korea. Field measurements of waves and currents were performed to identify the wave-induced current pattern associated with the observed shoreline erosion in front of the seawall. The construction of a short jetty and two submerged reef mounds was proposed to reduce the wave-induced current and resulting beach erosion. After the jetty construction from May to August, 2008, the shoreline advanced offshore continuously in the zone affected by the jetty. Field monitoring will be continued during the reef mound construction and for beach nourishment proposed to maintain a wide beach in front of the seawall. This mitigation project indicates that the effect of a coastal road on an adjacent beach should be taken into account before its siting because of the long-term evolution of the beach morphology.