【摘要】 基于ADCIRC与STWAVE模型,对海南新村港潮汐汊道的波浪-潮流联合作用进行了数值模拟,结果表明,S、SE向的平均浪与风暴浪在汊道近岸以产生西向沿岸流为主,SSW向平均浪与风暴浪作用时,在落潮主水道西侧形成东向沿岸流与西向沿岸流的交汇带。风暴浪作用下波生流与潮流的相互作用使瞬时流场与余流场均发生相应的变化。在平均浪作用时,汊道附近流速变化很小,而在风暴浪作用时流速增大,汊道内的涨、落潮流速不对称更为显著。在落潮主水道两侧由于波流联合作用产生涡漩,使动力减弱,从而造成泥沙落淤,而西向沿岸流的存在,使落潮主水道南侧边缘沙坝持续西移,泥沙沿落潮三角洲末端与冲流坝转运,导致新村港汊道口门西侧发育了规模较大的堆积地貌。更多还原

【Abstract】 Tidal inlet is the waterway which connects lagoon(or bay) with the open sea,and is maintained by the tidal current.Due to its importance in the navigation,aquaculture and fishing,tourism and environmental protection,it receives great attention in the estuarine and coastal study and engineering application.Xincun Inlet,located in the southeast coast of Hainan Island,is a rare natural harbor in this area.It is actually a semi-closed sand bar-tidal inlet-lagoon system with complicated topography and geomorphology.There is no evident runoff comes into the Inlet and wave and tide is the main dynamical factor.The tide is irregular diurnal tide with a mean tidal range of 0.69 m and maximum of 1.55 m.The rising tidal current hour is longer while the ebb tidal velocity is greater and the tidal hour and velocity asymmetry shows an ebb-dominated feature.Wind wave is dominant in the area with an annual frequency of 80% and predominant SE and S wave direction with an average percentage of 20% and 19%.The second most frequent wave is from SSE,with a percentage of 15%.The mean wave height is 0.7 m,and the mean wave period is 4.0 seconds.The maximum wave height recorded is 2.58 m.Based on ADCIRC model coupled with STWAVE model,combined tide-wave action in Xincun Inlet was numerically simulated and the results are as follows:When the SE mean wave moves shoreward,a longshore current from east to west is generated and becomes shoreward current in the inlet.There are clockwise and anti-clockwise vortexes developed at the east and west sides of the main ebb channel respectively.During a storm the longshore current is basically westward alongshore current and a clockwise vortex is formed to the south of the sand bar.And the wave bulge along the coastline is evident in the storm.The longshore current generated by the S mean wave is basically a westward alongshore current,and a clockwise vortex is formed near the sand bar.When the S storm wave maves shoreward,wave height peak areas near the ebb tidal delta and a complicated nearshore flow field is resulted.To the east of the ebb tidal delta,there develops a westward longshore current with localized clockwise vortext,whereas an anti-clockwise vortex is developed to the west.The SSW mean wave induces eastward longshore current to the west of the main ebb channel with localized anti-clockwise vortex,and clockwise vortex to the east.The SSW storm wave generates evident wave height peak zone to the south of the sand bar and produces stronger clockwise vortex.Under the action of SE storm wave,strong westward longshore residual current is produced near the main ebb channel.The S storm wave can induce similar residual current but smaller in magnitude.Under the action of SSW storm wave,the west side of the main ebb channel becomes the convergence zone of the eastward and westward currents,and the eastward longshore current is developed to the east of the channel near the shore.And to the south of the sand bar develops an anti-clockwise vortex.Under the action of storm wave,the water level at the inlet is enhanced.But if compared with the tidal level,the change of the phase of the water level is even more significant with a 180 degree phase shift produced.Because of the radiation-stress,the flood duration is lengthened,and the ebb duration is shortened.The flood velocity at the inlet is increased under SE storm wave,and the flood-dominance develops.Under SSW storm wave,flow velocity is strengthened and the ebb-dominance develops.From different combinations of the wave-tide interaction in Xincun Inlet,there generally develops westward longshore current to the east of the main ebb channel with localized vortex,which provides forcing for the westward extension of the sand bar in the south;to the west of the channel,there exists westward longshore current under the action of SE and S waves.The west of the main ebb channel becomes the convergence zone of westward and eastward current under SSW wave,which results in accumulation of sediments there.At the end of the ebb jet,the presence of the westward current provides a mechanism for the silt to transport from east to west along the end embankment of the ebb delta.All these results in the siltation in the west side of the inlet and the formation of a large scale attached sand bars and other curved sand bars.更多还原