| In a three-dimensional model of wind-driven currents in Meiliang Bay of Taihu Lake developed in this study, the water mass is divided into five layers vertically and the leap-frog method is used. The model is used to simulate the horizontal and vertical currents in Meiliang Bay. The currents are computed from the following equations:
where u, v, w are currents for x, y, z directions, respectively, p is water pressure, ρ is water density, g is acceleration of gravity, Ah, Av are horizontal and vertical diffusion coefficients.
After a constant southeasterly wind blows for 30 hours, the surface layer flow field accords with the wind direction, but the near lake bottom flow opposes that of the surface flow and shows characteristics of compensation flow. In addition, there exist vertical currents in the lake under the lasting action of wind. Looking from south toward north, a counterclockwise circulation is formed in the vertical profile in response to southeasterly wind and a clockwise circulation is formed in association with northwesterly winds. The results also show that the absolute horizontal flow velocity decreases from the surface to the bottom, whilst the absolute vertical flow velocity decreases from the shoreline to the center of the lake. |
