| 摘要: |
| 采用盐、淡水混合比的概念研究闽江口的混合状态,并确定了分层、部分混合、高度混合3种类型的分类指标。研究表明,闽江口主要水道的盐、淡水混合以部分混合为主,其次是分层,高度混合出现的机率较少;盐水异重流发育良好,混合状态的变化与潮流速的变化不相一致;盐水入侵时混合比相对较小,后退时相对较大。闽江口是一个径、潮量比值较小的强潮河口,按照一般规律,其盐、淡水混合应该出现高度混合型,但在闽江口的主汊道中发生的却是部分混合型,产生这种特殊现象的原因与河口分汊、会合、槽深等因素的作用有关。 |
| 关键词: 闽江口 盐 淡水混合 混合比 混合分类 |
| DOI： |
| 分类号: |
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附件 |
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| THE MIXING OF SALT AND FRESH WATER IN THE MINJIANG RIVER ESTUARY |
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Pan Dingan, Shen Huanting
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Institute of Estuarine and Coastal Research, East China Normal University, Shanghai 200062
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| Abstract: |
| The authors of the paper studied the salt and fresh water mixing in the Minjiang River estuary using the concept of mixing ratio. The mixing ratio is the percent of salinity at surface over that of the bottom. Let the mixing ratio bt M, Then M = (Ss/Sb) ×100%, where Ss=surface salinity, Sb=salinity at bottom. The bigger M is, the stronger the mixing is. The mixing is of stratified type when M<25%, partially mixed type when M=25% - 75%, and highly mixel type when M > 75%.
The type of salt and fresh water mixing in the major channels of the Minjiang River estuary is Mainly of the partially mixed type, and sometimes stratified type. The possibility of being highly mixed type displays rare.
The variation of the mixed degree and tidal current velocity is not consistent under the action of density current. The mixing strength is relatively weak as salt Water intrudes uppers-tream along the bottom. Otherwise, It is strong.
In general, The salt and fresh water mixing in the Minjiang River estuary should be of highly mixed type because of the strong tidal action, but the major bifurcated channels of the Minjing River estuary are of the partially mixed type. This is related to factors such as the estuarine branching, junction and channel depth. |
| Key words: Minjiang River estuary, Silt and fresh water mixing, Mixing ratio, Mixing classification |
