| 摘要: |
| 根据1991年洪季的实测资料分析了高度浑浊的椒江河口的混合过程，并探讨了水动力学和沉积动力学因素对河口混合的重要作用。调查研究表明，椒江河口最大浑浊带下的高浑浊水一浮泥层厚达1m，高浑浊水-浮泥层与上覆水之间是泥跃层。泥跃层与高混浊水-浮泥层对水体稳定的作用比同期观测到的盐跃层大17倍以上。当高浑浊水-浮泥层被侵蚀时，在高浑浊水-浮泥层中的低盐水体又增加了水体的垂向混合能力。 |
| 关键词: 高混浊水 河口混合 椒江河口 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，49276274号;浙江省自然科学基金资助项目，490013;国家海洋局二所一澳大利亚海洋研究院高浑浊水动力学合作研究项目 |
|
| MIXING PROCESS IN HIGHLY TURBID WATERS OF JIAOJIANG RIVER ESTUARY |
|
DONG Li-xian
|
|
Second Institute of Oceanography, State Ocean Administration, Hangzhou, 310012
|
| Abstract: |
| The Jiaojiang River Estuary is shallow, macro-tide dominated, highly turbid, and has large freshwater discharge variations. The mixing processes include phenomena such as freshwater front, salt wedge and vertical negative salinity gradient. This paper presents the analyzed result of the mixing processes in Jiaojiang River Estuary and the effects of both hydrodynamics and fine sediment dynamics using a set of observational ?eld data collected in April, 1991.
During spring tidal flood, the water column is vertically homogenous, but has a freshwater front in the estuary. A 1m thick fluid mud layer capped by a lutocline is formed when the tidal current velocity is less 0.3ms". The low-salinity water trapped in the fluid mud layer underlying more salty water enhances vertical mixing when the fluid mud layer is eroded.
During the neap, two lutoclines exist in the water column for 80% - 90% of observation time in two tidal cycles. The lutocline’s contributions to the water column stability are 17 times larger than that of the maximum salinity gradient ever observed throughout our study. The water column is stratified due to the lutoclines and the high suspended sediment concentrations inhibiting the vertical mixing. The freshwater front present in spring tide evolved into a salt wedge. |
| Key words: Highly turbid water, Estuarine mixing, Jiaojiang River Estuary |
