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基于珠江磨刀门河口2013年7月现场观测的悬浮物资料,综合同步测验的盐度、流速、悬沙浓度、水温,以及室内泥沙粒度分析数据,探讨了该区域泥沙絮凝特征及其主要影响因素,结果发现:磨刀门悬沙现场粒径平均达91.7μm,而平均分散粒径仅29.3μm;小潮泥沙絮凝较大潮明显,潮周期内憩流时刻絮团最大,可达200μm;絮凝效应垂向差异显著,表现为中层最大而表、底层较小;功率谱分析得到现场粒径具有3h、8h和24h的变化周期,其中8h与平均落潮周期相近,24h则与全潮周期相近。研究表明,控制磨刀门悬沙絮凝的因素主要为流速,絮凝临界流速约45cm/s;盐度则在弱动力条件下(流速<50cm/s)控制着河口泥沙絮凝,最佳絮凝盐度为21‰;悬沙浓度和温度对絮凝影响不显著;垂向水动力及盐度差异是导致絮凝效应垂向差异的主要原因。
The flocculation characteristics of sediment in this region were discussed based on the data of suspended solids observed on site in Pearl River Delta at July 2013, the salinity, velocity, suspended sediment concentration, water temperature and indoor sediment particle size analysis data of integrated synchronous test The main influencing factors are as follows: The particle size of Shaodongmen suspended sediment is 91.7μm on average, while the average dispersed particle size is only 29.3μm. The tide of small tide sediment is more obvious than that of tidal flat, ; Flocculation effect vertical significant difference, showing the middle of the largest and table, the bottom is small; power spectrum analysis of the field particle size with 3h, 8h and 24h of the change cycle, of which 8h and the average ebb cycle is similar to 24h and full tide cycle similar. The results showed that the main factors controlling the flocculation of Sabotian suspended sediment were flow velocity and the flocculation critical velocity was about 45cm / s. The salinity was controlled under the weak dynamic conditions (velocity <50cm / s) The degree of 21 ‰; suspended sediment concentration and temperature on the flocculation was not significant; vertical hydrodynamic and salinity differences are the main reasons leading to vertical differences in flocculation effect.