黄河口常量离子运移规律研究Ⅰ—常量阳离子

Transportation of Major Constituents in the Estuary of the Yellow River Ⅰ-Constant Cations

研究和探讨黄河入海过程中常量离子的分布特征和运移规律,于2004年11月、2005年5月和2005年9月沿黄河口盐度接近于0～28水域。进行走航站位表、底层水体中溶解态的K^+,Na^+,Ca^(2+)及Mg^(2+)4种常量阳离子浓度的调查。结果表明,4种常量阳离子均与盐度的变化成正相关,发生突跃的区域即是淡—咸水的剧烈混合带。3个航次常量阳离子对总离子浓度的贡献次序是相同的:(1)盐度<5时,Na^+>Ca^(2+)>Mg^(2+)>K^+;(2)盐度>5时,Na^+>Mg^(2+)>Ca^(2+)>K^+。通过稀释比与阳离子浓度的关系比较发现,在黄河口河水区,离子非保守行为不明显,而在混合区,离子非保守行为显著,进入海水区后离子行为保守。离子在输运过程中表现出由淡-咸水的物理混合控制为主,生物和化学因素为辅的特征。

In order to study the chemical behavior of constant cations(K,Na,Ca and Mg),surface and bottom waters were collected in the Estuary of Yellow River(salinity ranged from 0.5 to 28)in November, 2004 and May and September,2005.The results show that the concentrations of cations increased with salinity and the constant cations in the surface and bottom waters had a similar variation trend.A sharply growing area was detected during the migration process,which was a violent mixing zone between freshwater and seawater.In the three cruises,the relative contribution of cations followed similar orders:(1)When S<5,Na^+>Ca^(2+)>Mg^(2+)>K^+;(2)When S>5,Na^+>Mg^(2+)>Ca^(2+)>K^+.The relationship between the dilution ratios and the concentrations of chemical elements indicated that,cations were non-conservative in the mixing waters and conservative in seawaters,while the non-conservative behaviors were insignificant in riverwaters.The concentrations of constant ions were primarily controlled by the physical mixing dilution of freshwater with seawater,and partially effected by biological and chemical factors.