【摘要】 本文对未忽略非线性加速度项的二维潮汐水力学方程,按特征理论推导出特征-差分格式.对杭州湾海区进行了实例计算,算得结果和实测值符合较好.然后再在河口建坝条件下进行计算,并对计算得出的建坝前后杭州湾潮波变化作了分析比较。文末还对计算变量的选取、非线性项影响和边界条件的给定等问题作了初步讨论.更多还原

【Abstract】 This article describes a mathematical model for the tides in a bay. The objective is to anticipate with this model the effects that closing off of an estuary may have on the tides in an adjoining bay. As the area investigated is 105 km long and 25 to 65 km wide, a depth-integrated, two-dimensional model is employed. Schemes for finite-difference computations have been derived by applying the theory ofc haracteristics to the full equations of motion with the convective acceleration terms retained. Altogether 12 types each of land and water boundary conditions have been considered .In the first place, tides in the bay under natural conditions are modeled. By adjusting the resistance coefficient and by proper schematization of the topography of the bay, satisfactory reproduction of the tides can be achieved. Whereas the maximum deviation of the computed tidal stage from the observed is 0.26 m at high tide at a station where the tidal range is 6.20 m., the phases of computed and observed tides are practically identical at all tidal stations.There is a station where depth-integrated current data for a complete tide have been recorded. It is somewhat surprising that the current data are closely modeled in magnitude, phase and direction.On the basis of successful modeling of the natural tides, the closure of the estuary is next simulated and the corresponding tides in the bay computed. It is found that high water at the closure dam will come sooner than under natural conditions and that the high tide is lowered and the low tide elevated so that the tidal range at the closure dam is reduced somewhat.更多还原