廉州湾三角洲泥沙运移与海洋动力条件的关系

The Relationship of Silt Transportation and Ocean Dynamical Condition in Delta of Lianzhou Bay

根据已经报道的文献和相关调查资料,分析廉州湾水体中的悬沙浓度分布、重矿物比值沿程变化和沿岸动力地貌特征等因素,探讨廉州湾三角洲泥沙运移状况与海洋动力条件的关系。廉州湾水体中的悬沙浓度南部低于北部,从东北向西南和自北向南递减,在南流江入海汊道口门附近为浓度高值区;比重较小的重矿物物质大量沉积在廉州湾潮间带上、下部,比重较大的物质主要沉积在河床、潮下带及湾口门附近;廉州湾南部北海半岛绕过冠头岭形成指向东北的水下沙嘴,南流江水下三角洲呈舌状向海突出,中部较深,向两翼变浅。潮流、径流和波浪是廉州湾三角洲泥沙运移的主要动力因素,廉州湾内泥沙运移总趋势为自东北向西南,但北海半岛沿岸向东北运移。

In light of the reported literatures and relevant data,the paper analyzes consistency distribution of suspended sediment,changes of heavy minerals ratio in water and dynamical physiognomy characteristics along the bank,and discusses the relations between status of silt transportation and ocean dynamical condition in delta of Lianzhou Bay.The results show that the consistency of suspended sediment in the south is lower than that of the north,and gradually decreases from the northeast to southwest and from north to south.The consistency is high around estuary of Nanliu River in Lianzhou Bay;Heavy mineral substances of smaller proportion deposit mostly at top and bottom area in intertidal zone.Mineral substances of bigger proportion deposit mostly at river bed,subtidal zone and around mouth of Lianzhou Bay;Beihai peninsula forms an underwater spit northeastwards round Guantou ridge at the south of Lianzhou Bay.Underwater delta of Nanliu River sticks out towards the sea shaping like a tongue,deep in the middle and shallow along both sides.Tidal current,stream flow and wave are the main dynamical factors forsediment transportation in the bay,and the total trend of sediment movement is from northeast to southwest,but from southwest to northeast along Beihai pensinsula.