三峡工程对长江口海区营养盐分布变化影响的研究

A STUDY ON THE EFFECTES OF THE THREE GORGE PROJECT ON THE DISTRIBUTIONS AND CHANGES OF THE NUTRIENTS IN THE CHANGJIANG RIVER ESTUARY

本文通过1986年8月—1988年10月期间共5个航次长江口及其邻近海域的调查和历史资料,进一步验证了作者提出的长江径流量与营养盐输出通量之间的关系式。讨论了春季营养盐分布的年际变化及其与长江径流的关系。根据秋季10月实测资料对比和定量估算,三峡工程兴建后,由于长江径流减少(主要在10月),可能引起长江口海区营养盐平均浓度下降,等值线向江口移动,高浓度区域面积缩小等影响。

In this paper, the correlative equations between the flows of the Changjiang River water into-the sea and the output fluxes of the nutrients proposed by author were verified on the base of five cruises investigations in the Changjiang River estuary and its near seas from August, 1986 to October, 1988 and historical data in recent years. It shows that in addition to ammonia, the exponential correlationships between the output fluxes of the nutrients and the flows of the Changjiang River water are all possitive. The annual average output fluxes of the phosphate, silicate, nitrate, nitrite, ammonia and total inorganic nitrogen from the Changjiang River water into the sea were estimated to be 1.51×104, 222.10×104, 69.10×104, 0.46×104 8.79-10×104 and 91.20×104 tons respectively. The annual changes of the distributions of the nutrients in April and October and the relationships between them and the flows of the Changjiang River water were also discussed. It is possible that if three Gorge reservoir is built, the average concentrations of the nutrients in the Changjiang River estuary seas will decrease, the isograms will move toward the river mouth and higher condensation areas of the nutrients will reduce due to the decreas in the flow of the Changjiang River water (in October).