Preliminary study on the forecast method of wind velocity distribution above the sea surface in near-shore waters

From the hydrodynamic feature of the near-shore waters, the actual flow mainly is induced by tidal, wind, salinity, and the run-off should also be included as a component in the estuary waters. Based on the theoretical velocity distribution of the tidal current and the wind-induced current and so on, a method to separate the observed current into the wind induced current by use of the least square method combination of enumeration is advanced. First of all, for verification of its value, this method is applied to the velocity data observed from the North Branch of Yangtze River estuary and laboratory test data. All the results are satisfactory. Then, it is applied to the South Branch of Yangtze River estuary. By use of this approach, not only is the surface velocity of wind induced current obtained, for estimating the wind velocity above the water surface, but also is the friction wind velocity determined. Finally, by combination of the logarithmic distribution of wind velocity, the distribution in low layers over the sea surface is predicted. The research results show that this method is simple in principle, feasible in process, and reasonable in result. So this method is a valid method to analyze and calculate the field data.