This study presents a comprehensive analysis the physical oceanographic characteristics of the coastal area around the Sihwa Tidal Power Plant using observational data collected from 2012 to 2024. Long-term records of current direction and velocity, water temperature, salinity, density, water level, and waves were analyzed to review hydrodynamic and environmental conditions associated with plant operation. The study area was divided into sea-side and lake-side regions, and field observations, including current measurements and seasonal vertical profiling, were used to compare physical characteristics between the two areas.
The results revealed that flow characteristics around the tidal power plant varied with tidal phase, depth, and spatial location, and that current distribution patterns differed between the sea-side and lake-side regions. In the sea-side area, reduced current velocity was observed in the frontal zone of the plant after the installation of current reduction structures, with decreases of more than 50% in some sections, although spatially mixed responses were also present in other areas. In the lake-side area, stratification became more pronounced in the upstream region under the combined influence of plant discharge and freshwater inflow, particularly during discharge periods and in summer. Furthermore, the observational data captured short-term variability in surface flow and major environmental parameters linked to the plant’s operational cycle.
These findings provide a long-term, observation-based characterization of the physical oceanographic regime around the Sihwa Tidal Power Plant and are expected to serve as fundamental reference data for sustained monitoring of flow structure evolution and marine environmental changes associated with plant operation, thereby supporting evidence-based coastal management strategies.

Sihwa Tidal Power Plant,Long-Term Monitoring,Coastal Hydrodynamics,Current Structure Analysis,Ocean Stratification Variability