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

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 S5,Na~+Ca~(2+)Mg~(2+)K~+;(2)When S5,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.