Estimation of vertical profile parameters and tidal current velocity assessment in Uldolmok Strait

Tidal energy candidate sites characterized by strong current velocities often exhibit physical conditions distinct from those of general coastal environments; however, field-based analyses of vertical tidal current profiles in such areas remain limited. This study investigated the vertical structure of tidal current velocity at the Uldolmok Strait, Korea using two months of measurements from an acoustic Doppler current profiler and compared velocities derived from representative evaluation methods based on layer-specific observations. Using the power law and logarithmic profile approaches, key parameters were estimated, including the power law exponent α (4.40–12.24), bed roughness β (0.38–0.41), friction velocity u∗ (0.08–0.164 m/s), and roughness length z0 (0.007–0.212 m). Correlation analysis of the estimated parameters revealed significant relationships between tidal current velocity and friction velocity, as well as between bed roughness and roughness length. Among the three representative velocity evaluation methods, the IEC TS 62600-200-based approach yielded values up to 31.2 % higher than those obtained with conventional averaging methods. By applying standardized evaluation techniques and vertical profile analysis tailored to the site's hydrodynamic characteristics, this study provided essential baseline data for the design and performance evaluation of tidal energy converter systems.