太湖风浪场的计算与比较

首先探讨了浅水风浪数值模型—SWAN模型应用于模拟内陆湖泊风浪生成和传播变形时的特点。该模型存在不能有效地模拟近固壁边界处风浪场的缺点,以能正确地模拟湖区的风浪场和节约计算时间为原则,确定了计算范围。对太湖进行了风场和风浪场的现场观测。分别利用规范公式和SWAN模型两种方法、根据观测和预报的风场计算了湖区的有效波高,并将计算结果和现场观测值进行了详细比较。结果表明基于观测的风场,利用两种方法所计算的太湖风浪场的精度基本相当;在根据观测的风场、利用SWAN模型计算内陆湖泊的风浪场时,需要精心选择恰当的风场;在根据预报的风场预报湖区风浪场时,SWAN模型的精度要高于规范公式的精度。

Comparisons of calculated wave heights in Taihu Lake

The characteristics of the wave model Simulating Waves Nearshore (SWAN) are found when the model is applied to simulate the wind wave generation and propagation in the inland lakes. In view of the drawback of the SWAN model that it can not effectively simulate the wave field near the solid boundaries, the calculation domain of Taihu Lake is determined after modeling test. When the calculation domain is determined, the principles should be obeyed that the wind waves in the lake district can be simulated properly and that the computing time is not wasted. The wind field and wind wave field are measured. The significant wave heights are calculated by use of normal formula and the SWAN model, with the measured and predicted wind field input, respectively, and the calculated results are compared to the measured data in detail. It is indicated that the precisions of the calculated results according to the normal formula are similar with those of SWAN model if the measured wind field is input. When the wave field is simulated by use of SWAN model according to the measured wind field, the measuring locations should be arranged carefully and the wind field should be selected properly. The precisions of the calculated results according to the SWAN model are greater than those of the normal formula if the predicted wind field is input.