On Methods to Calculate Average Tidal Current Velocity

In coastal, estuarine and bay waters, tidal current is the basic sea water movement and one of main hydrodynamic factors. Affected by bottom topography, coastline and islands, the tidal current assumes itself to-and-fro movement, that is, the flood current and ebb current are basically in the opposite direction, with difference of about 180°. One of the important indexes to depict to-and-fro tidal current force is tidal average current velocity during flood tide or ebb tide. Integrating measured tidal current process in practical sea area, this paper carries out studies and comparisons on three methods to calculate tidal average current velocity during flood tide or ebb tide and three methods to calculate tidal average current velocity in a complete tidal cycle. The study show that there exist differences in the results from different methods. It is suggested that tidal average current velocity during flood tide or ebb tide be calculated by integral average method and tidal average current velocity in a complete tidal cycle by weighting average method.