论文部分内容阅读
根据2014年10月对黄河口附近海域56个站位水质的调查结果,分析了该海域营养盐的空间分布特征,并对该海域的营养水平和有机污染状况进行了评价。结果表明,该调查海域表、底层无机氮(DIN)平面分布表现为近岸向远岸降低的趋势,特别是在黄河口附近有高值区,且与盐度有显著负相关性,表明DIN主要来自黄河等入海径流的输入。表层海水中活性磷酸盐(PO4-P)平面分布表现为东北高西南低的趋势;底层海水中PO4-P平面分布较为均匀;PO4-P与海水盐度相关性不十分显著,表明调查海域PO4-P的补充并非主要来自黄河口等河流输入,而可能与有机物的分解矿化再生、浮游植物的大量繁殖以及海底表层沉积物中PO4-P向上输送补充等因素有关。从营养盐结构看,本次调查海域N/P均值大于Redfield比值;P与N相比显得相对缺乏。根据N/P比值与浮游植物生物密度平面分布表明,过高比值的N/P可能引起浮游植物的生长受到某一相对低含量元素的限制,从而导致浮游植物的生物密度较低。根据富营养化指数评价和有机污染综合指数计算结果,2014年秋季黄河口附近海域已处于富营养化状态,而DIN应是造成黄河口附近海域富营养化的主要因子;该海域有机污染程度属于2级,表明该海域开始受到有机污染。
According to the survey results of water quality of 56 stations near the Yellow River estuary in October 2014, the spatial distribution characteristics of nutrients in this area were analyzed. The nutrient levels and organic pollution in this area were also evaluated. The results showed that the distribution of surface inorganic nitrogen (DIN) in the survey sea area showed a trend of decrease from near shore to far shore, especially in the high value area near the Yellow River mouth and a significant negative correlation with salinity, indicating that DIN Mainly from the Yellow River into the runoff input. The distribution of active phosphate (PO4-P) in surface seawater showed a trend of low in the northeast and high in the southwest. The distribution of PO4-P in the bottom seawater was even. The correlation between PO4-P and seawater salinity was not significant, -P supplement is not mainly from the Yellow River estuary and other rivers, which may be related to the decomposition and mineralization of organic matter, the large-scale propagation of phytoplankton, and the upward transport of PO4-P in sub-surface sediment. From the perspective of nutrient structure, the average N / P in this survey area is greater than that of Redfield; P is relatively scarce compared with N. According to the N / P ratio and phytoplankton density distribution, it is indicated that overly high ratio of N / P may cause the growth of phytoplankton to be limited by a relatively low content of elements, resulting in low biological density of phytoplankton. According to the eutrophication index and the comprehensive index of organic pollution, the sea area near the Yellow River estuary in the autumn of 2014 was in an eutrophic state, while DIN should be the main factor of eutrophication in the sea near the Yellow River estuary. The organic pollution in this area belongs to Level 2, indicating that the sea began to be organic pollution.