潮流、风暴潮耦合模型推算珠江口海域极值流速

分别采用模式气压场及模式台风场计算气压分布及风速分布，采用地形拟合的sigma坐标水动力方程组及紊流方程建立了潮流、风暴潮耦合模型。三维水动力方程组通过分裂算子法与Casulli半隐式差分格式直接求解。在珠江口的极值流速计算中，先进行了南海北部的潮流、风暴潮耦合模拟，模拟水位与实测值符合较好。以六区域模拟结果为边界，采用嵌套网格方法，在珠江口进行了高分辨率的潮流、风暴潮耦合模拟。选用1968～1999年共65个影响工程区域的台风过程，计算出珠江口的海域年极值流速序列，分析了该海域多年一遇的极值流速分布。

Extreme current velocities in multi-year return periods in the Zhujiang estuary calculated from a coupled tide-surge model

By using the typhoon atmospheric pressure mode and typhoon wind field mode to calculate the distributions of atmospheric pressures and wind speeds respectively, and by using topography-following sigma coordinate primitive hydrodynamic equations and the turbulence model, the present paper establishs a coupled tide-surge model, in which the hydrodynamic equations are directly solved by operator splitting technique and Casulli difference scheme. To calculate the extreme current velocities in multi-year return periods in the Zhujiang River estuary, the tide-surge currents in the northern South China Sea are modeled first, and the calculated time series of water levels at the gauge stations agree well with the ones measured. Then, in the Zhujiang River estuary the high-resolution tide-surge currents are modeled by means of mesh-nesting technique. Modeling 65 typhoon processes, severely affecting the Zhujiang River estuary from 1968 to 1999, forms the yearly maximum current velocity series of every computational grid. Finally, the extreme current velocities in multi-year return periods are calculated at every computational grid.