大风浪影响下海域泥沙输运异变数值模拟

基于实测的水深、潮流、悬浮体、底质数据及历史气象资料等,采用导入SWAN波浪参数的ECOMSED三维模型,模拟大风浪对小清河口附近海域悬浮体浓度和底床冲淤变化的影响程度。并利用全潮水文观测资料对水动力和输沙率模拟结果进行检验,对比分析表明计算值与实测值吻合良好。模拟结果表明,大风浪影响下近岸海域泥沙输运变化较大,悬浮体浓度可达一般天气的10倍左右,而底床冲淤变化可达平时的百余倍。大风浪期间剧烈的底床冲淤变化对河口拦门沙演化影响较大。

Numerical simulation on characteristics of sediment transport under strong wind and waves

We simulate the effect of strong waves on the sediment transport at the Xiaoqing River estuary areas using the 3D model ECOM SED(Estuarine Coasta lO cean Model with sedmient transport) with the wave parameters from the wave model SWAN(Simulating Waves Nearshore).The water depth,tidal current,suspended sedmient and historicalm eteorological data are used to estmiate the changes of the suspended sediment concen trations(SSC) and the bed scour and siltation(BSS) caused by strong wind and waves.We compare the smiulation with the in situ data and find that the results are reliable.Results show that the sedmient transport change greatly under the influence of strong wind and waves in the near shore areas.The value of SSC is 10 times larger than that under the normal wind and wave condition.The change of BSS could be even as much as one hundred times.The result also show that the change of BSS resulting from strong wind and waves would have a great impact on the evolution of river estuary sandbars.