【摘要】 沙纹微地形普遍存在于海底,沙纹的消长能改变底部应力进而影响泥沙的运移。以往研究较多侧重于波致沙纹,并已应用于波浪模式的底摩擦计算,而较少考虑波流联合效应产生的沙纹,也未将其应用于综合的水动力模式和沉积物输运模式。本文在POM水动力模式中嵌入新南威尔士大学泥沙模式,通过耦合波流共同作用的微地形模型与波流相互作用底边界层模型,发展了波浪-海流-微地形(沙纹)耦合的沉积动力模式。本文将该模式应用于澳大利亚Jervis湾,针对波主导和波流联合主导沙纹两种类型,分别进行了沙纹发展状态、几何形态的分布及悬浮泥沙的模拟。结果表明:波致沙纹比波流联合作用的沙波具有更大的波高和波长,因此当波主导时沙纹对悬浮泥沙起着关键作用。通过考虑随沙纹变化的粗糙度,相比于以往模式设置均一的粗糙度,该模型能对悬浮物浓度的骤升过程进行更精细的预测。更多还原

【Abstract】 Ripple microtopography prevalently exist on coastal beds,which significantly change the bottom stress and then influence the sediment transport.Previous researchers mainly study the wave-dominant ripples and have applied them to the wave modelling.Wave-current combined flow is rarely discussed to generate ripples,and the combined flow-dominant ripples are rarely implemented to hydrodynamic and sediment models.We embedded the University of New South Wales sediment model into the POM model,and connected them with a wave-current interaction bottom boundary model coupled with a microtopography module under combined flow.We developed a wave-current-microtopography coupled model of sedimentology dynamics,and applied this coupled model to Jervis Bay,Australia.Developing stages and types are modeled,and the ripple height and length are simulated.The suspended sediment transport was analyzed under wave-dominant and combined flow separately.Simulated results show that the wave-dominant ripples have longer height and length.Therefore,ripples place an important role on suspended sediment when waves dominate.Through considering roughness that varies with microtopography,this model can predict the abrupt rising of suspended sediment concentration rather than setting an average uniform roughness.更多还原