Seawater intrusion areas were calculated in Yeosu region considering sea level rise and the effects of countermeasures for seawater
intrusion were analyzed using SEAWAT program. The estimated seawater intrusion area was 14.90 km2in 2015. When we applied
climate change scenarios the area was changed to 19.19 km2 for RCP 4.5 and 20.43 km2 for RCP 8.5 respectively. The mitigation effects
by artificial recharge with total 50 m3/d, 100 m3/d, and 300 m3/d are from 3.75% to 10.68% for RCP 4.5, and from 5.82% to 10.77% for
RCP 8.5 respectively. If we install barrier wall with the thickness 0.8 m, 1.3 m, and 1.8 m, the mitigation effects are from 6.67% to
12.04% for RCP 4.5, and from 6.17% to 14.98% for RCP 8.5 respectively. The results of this study can be used to be a logical means
of quantitative grounds for policy decisions to prevent groundwater contamination by seawater intrusion and subsequent secondary
damage in coastal areas.