摘要
基于单宽断面潮周期平均水体和物质对流输运通量,定义了二维水体和物质长期输运速度,它们分别描述单宽断面水体和物质长期输运的方向及快慢。通过二维水体和物质长期输运速度的对比分析,提出了物质和水体长期输运分离概念:受物质浓度影响,在物质和水体瞬时运动速度相同的情况下,物质和水体潮周期平均对流输运的方向和快慢可能存在差异。本文将二维物质长期输运速度分解为二维水体长期输运速度、二维潮泵输运速度和垂向切变输运速度,它们分别描述余流输运、潮泵输运和垂向切变输运,后两种输运造成单宽断面物质和水体长期输运分离。本文的分析表明,河口受地形、径流、潮流、密度梯度影响,存在有利于物质和水体长期输运分离的自然条件。
Based on the tide-averaged convection flux of water and substance at unit length vertical section, 2-D water and substance＇s long-term transport velocity is defined, which describe the water and substance＇s long-term transport direction and speed at unit length vertical section. 2-D water and substance＇s long-term transport velocity can also introduce the separation of water and substance＇s longterm transport, namely in the case that substance＇s convection velocity is as same as water＇s at every tide phase, their tide-averaged convection velocity may be different in direction and speed because of substance concentration＇s impact. 2-D substance＇s long-term transport velocity is decomposed as 2-D water＇s long- term transport velocity, 2-D tide pumping transport velocity and vertical shear transport velocity, which describe the substanee＇s long-term transport from residual current transport, tide pumping transport and vertical shear transport respectively. Tide pumping transport and vertical shear transport result in the difference of water and substanee＇s long-term transport at unit length vertical section. In estuary, the topographty, river flux, tidal current and density grads make favorable entironment for the separation of water and substance＇s long-term transport.
出处
《海洋学报》
CAS
CSCD
北大核心
2008年第6期24-29,共6页
基金
国家973计划资助项目(2002CB412403)
国家自然科学基金(40306014)
海洋公益性项目(200705013)
关键词
河口
物质长期输运
水体长期输运
分离研究
estuary
the substance＇s long-term transport
the water＇s long-term transport
separation study
