长江入河口区水沙通量变化规律

PATTERNS OF VARIATIONS IN THE WATER AND SEDIMENT FLUXES FROM THE CHANGJIANG RIVER TO THE ESTUARY

根据大通站１９５０－１９８５年的水、沙实测资料，运用统计分析方法研究长江人河口区水、沙通量的季节性变化、年际变化以及水、沙通量之间的关系。结果表明，长江人河口区的水沙通量有明显的季节性变化，其中沙通量的变化更为显著；丰水年很少连续出现，枯水年有７５％以连续两年的形式出现；多沙年的出现形式有１年出现一次的，也有２－３年出现的，少沙年基本上以连续２－３年的形式出现；水沙通量间的相关性较差，其中细颗粒泥沙通量与水通量间基本上无相关性。

According to the field measurements of runoff and sediment at the Datong hydrological station in the period from 1950 to 1985, a statistical approach is applied to study the seasonal and yearly variations in water and sediment fluxes to the estUary and their relationship. The result shows that: (1) an apparent seasonal variation of water and sediment fluxes exists, especially the suspended sediment flux; (2) the flood years seldom occur in succession and 75% of the dry years takes place every two years, (3) the recurrence interval of high sediment years happens once a year or 2-3 years while that of low sediment years basically every three years, (4) there is a relatively poor correlation between water and sediment fluxes. Moreover, there is almost no correlation between fine grained sediment flux and water flux.