Coastal flooding alert issued for Incheon as spring tides approach

Sea levels along the west and south coasts are expected to rise significantly above normal this week, prompting warnings of flooding in low-lying coastal areas. Incheon in particular is forecast to reach the "Alert" level — indicating a high probability of inundation — on Friday and Saturday.

The Korea Hydrographic and Oceanographic Agency under the Ministry of Oceans and Fisheries announced Tuesday that sea levels are expected to rise above normal during the lunar spring tide period running from Thursday through Sunday.

Spring tides occur when the moon, sun and Earth align closely, amplifying the difference between high and low tides. When high tide coincides with this period, seawater rises higher than usual, increasing the risk of flooding in low-lying coastal areas.

According to the agency, high-tide alerts for areas along the west and south coasts — including Incheon, Gunsan, Changwon and Jeju — are expected to reach the "Caution" level or higher during this spring tide period.

The agency classifies coastal flooding risk from rising sea levels into four tiers: Attention, Caution, Alert and Danger. The Caution level indicates a possibility of seawater flooding, while Alert signals a high probability.

Incheon is forecast to see sea levels climb to the Alert tier on both Friday and Saturday. Temporary flooding in low-lying coastal areas is possible during high-tide windows on those days.

Because the spring tide period coincides with the peak summer vacation season, the agency also urged beachgoers to take extra precautions. Rapidly rising tides can strand people on tidal flats, and large waves can sweep over coastal walkways and breakwaters.

During the spring tide period, the agency will provide local governments and relevant authorities with high-tide schedules and projected sea levels by region, and will step up real-time sea-level monitoring.

Field surveys will also be conducted to improve the accuracy of flooding projections. In five areas — Incheon, Busan, Changwon's Jinhae and Masanhappo districts, Geoje and Tongyeong — drones and other survey equipment will be deployed to assess actual inundation ranges.

Real-time sea levels by region are available through the agency's real-time high-tide information service.

Cha Seong-sin, acting director of the Korea Hydrographic and Oceanographic Agency, said the August spring tide period carries an elevated risk not only of coastal flooding but also of safety accidents involving summer vacationers, given the larger-than-usual rise in sea levels. "Please follow safety guidelines as directed by local governments during high-tide hours," he said.