Kim, M.-J.; Kim, C.-S.; Choi, B.-J., and Lee, S.-H., 2018. Plume Current Change by Seawall Construction for a Harbor Development in South Korea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 126–130. Coconut Creek (Florida), ISSN 0749-0208.

The present study investigates the effects of a seawall construction on the nearfield plume dispersal and surface circulation in the west coast of Korea where the Saemangeum tide dike (33 km long) had been constructed from 1993 to 2006 to reclaim the wide tidal flat in the riverine estuary. The plume water has since flowed out by the gate operation from the two sluices (11 km apart) in the southern dike to the offshore, which altered source location of the plume in the coastal sea. Recently a 3.5 km long seawall was constructed at 4 km offshore from the northern sluice. The changes of the plume current and surface circulation near the newly constructed seawall were examined using data set of High Frequency Radar-derived current (HFR-current), wind and sluice-outflow velocity in summer 2010 (before the seawall construction) and summer 2014 (under the seawall construction). It was found that construction of seawall evidently changed tidal plume dispersal pattern and nearfield distribution of monthly-mean plume current. Complex correlation and Empirical Orthogonal Function (EOF) analyses on the subinertial surface current, wind, and sluice-outflow velocity in summer 2010 and summer 2014 revealed that wind and outflow velocity are dominant factors controlling variations of the plume extension and coastal current.