磨刀门水道盐度混合层化机制

基于Simpson方法和磨刀门水道2009年枯季水文实测资料,选取上、下游两个站位的径流层化、潮汐混合、风致扰动3个影响河口水体分层的主要因素进行盐度混合的层化机制分析。研究表明:由于M1站位处上游,径流作用相对占优,分层不明显,只在涨潮急流时出现微弱的盐度分层;M2站则水体分层明显,小潮期间径流作用占主导,水体呈持续性分层,当由小潮转为中潮后,潮流作用增强,出现周期性分层现象,大潮以后,由于上游径流增加,潮流与径流作用相当,仍为周期性分层,但分层有所加强。层化的发育程度依赖径流致层化作用与潮汐、风致混合作用的博弈。

Research on salinity mixing and stratification mechanisms at the Modaomen channel

Based on Simpson’s method and observation data of the Modaomen channel in the dry season in 2009,the paper discussed salinity mixing processes and stratification mechanisms with tidal straining,freshwater buoyancy inputs,stirring of wind at upstream and downstream stations.The results are as follows:(1) the impact of freshwater on stratification is weak at the upstream M1 station;and(2) stratification is obvious at downstream M2 station with continuous stratification during neap tide and cycle stratification during middle tide and spring tide,but stratification is strengthened during spring tide because of input freshwater increases.Weak stratification at the M1 station appears only at then maximum current during flood tide.Degree of stratification depends on ratio of Freshwater buoyancy to mixing inducing tide and wind.