1998年夏季长江特大洪水入海的化学水文学特征

Chemicohydrographic Characteristics in the Shelf Area During the Changjiang River Catastrophic Flood Period in the Summer of 1998

根据1998年夏季长江流域特大洪水期间黄海、东海的现场调查资料,讨论了洪水入海对黄海和东海陆架区化学水文学的影响。给出了迄今调查获得的长江冲淡水及其营养物质的最大扩展范围;发现了表层溶解氧和pH分布的一个突出现象,即在南黄海南部和东海北部的远岸海域存在一溶解氧和pH高值封闭区;指出浮游植物的光合作用主要发生在南黄海南端至东海北部海域,而不是在长江口门内。南黄海南部、东海北部和东海近岸海域过量无机氮的存在表明,与其它海洋生态系统不同,上述海域的初级生产可能是磷限制而非氮限制。

Based on the observed data during the catastrophic flooding period, the impact of the Changjiang River catastrophic flood on the chemicohydrography in the shelf area of the Yellow Sea and East China Sea in the summer of 1998 is dissussed. The maximum extending ranges of Changjiang Diluted Water and its nutrients in history were observed, and it was found that there was a closed area with high dissolved oxygen and pH values in the offshore area of the southern Yellow Sea and the northern East China Sea, which indicates that the photosynthesis of phytoplankton took place mostly in the offshore area rather than the river estuary area. The presence of `excess nitrogen` in the northern East China Sea and the southern Yellow Sea indicates that unlike other marine ecological systems, the primary production in above sea areas might be Plimited rather than Nlimited.