水动力时空变化对近岸风浪演化的影响——以渤海湾西南岸为例

Influence of Hydrodynamic Factors on Nearshore Wind Waves——the Southwest Coast of the Bohai Bay as an Example

采用SWAN模型和ADCIRC模型建立了风浪、潮汐和水流联合作用的耦合数值模式,并通过渤海湾西南岸实测资料对该模式进行了验证。利用该模式分析了近岸区水位和流场时空变化对风浪模拟结果的影响,计算结果表明水位变化对近岸区风浪模拟结果有显著影响,特别是中等大风过程高潮位时波高受水位影响的变化幅值可达0.5m以上,且水深越浅影响越大。但在岸滩平缓的近岸海域由于流速、流向的时空变化不太剧烈,流场作用和波浪辐射应力作用对波浪场的影响都基本可以忽略。在模拟近岸风浪过程时,应选用耦合模式。

The SWAN and ADCIRC models were applied to develop a coupled numerical model of wave, tide and current. The models were verified by measured data from the southwest coast of the Bohai Bay. The coupled model was used to examine how spatio-temporal water level and current would affect simulated wave results. It is shown that the water level has significant influences on numerical wave results. The wave height can increase more than 0.5 meters in the high tide level of a medium-scale wind process. The shallower the water depth is, the more notable the water level influence becomes. Because the changes of current velocity and direction on the mild beach are not remarkable, the influences of the current and wave radiation on wave filed can be nearly ignored. It is suggested that a coupled hydrodynamic-wave model should be used when the nearshore wind waves are simulated.