中文摘要：

2001年3月-2002年2月期间在黄河下游采集溶解及颗粒态营养盐样品，分析了黄河径流中各形态的营养盐的浓度及其月动态，估算此时段内黄河的营养盐人海通量。研究发现，溶解无机氮是溶解总氮的主要存在形式，硝酸盐是黄河中氮的最主要存在形态，其季节变化与水量变化趋势相反，年平均含量为（260．6±84．0）μmol／L，显著高于世界其它河流，为世界背景值（7．14μmol／L）的20多倍；黄河中磷主要以颗粒态存在，颗粒态磷含量变化规律与SPM的分布一致，其年平均含量为（16．2±22．9）μmol／L，磷酸盐含量较低，年平均含量为（0．42±0．20）μmol／L，与世界河流的平均水平相当。硅酸盐年平均含量为（122．0±18．2）μmol／L。每年约有17200t的总氮和1600t的总磷输入渤海，氮通量表现出在春季3月较高；磷通量在9月出现最高值，春季3，4月也较高；硅酸盐通量在3月出现最高值。

英文摘要：

Dissolved and particulate samples were collected from the low reaches of Yellow River i from March 2001 to February 2002 to determine the nutrient species. The variations and fluxes of nutrients were studied. The result showed that dissolved inorganic nitrogen （DIN） was the predominant species of TN. Nitrate was the predominant species in the Yellow River. No significantly relationship was found between nitrate and water discharge. The average concentration of nitrate was （260. 6±84. 0）μmol/L, which was significantly higher than the world background value. Particulate phosphorus was the predominant species of TP in the Yellow River, and it correlated well with suspended sediment discharge. The average concentration of particulate phosphorus was （16. 2±22. 9）μmol/L. The average concentration of phosphate was （0. 42±0. 20） μmol/L, which was relatively low and comparable to the world average lev- el. The average concentration of silicate was （122.0±18. 2） μmol/L. Yellow River input about 17 200 t of total nitrogen （TN） and 1 600 t of total phosphorus （TP） to the Bohai Sea. The highest fluxes were found in March for TN, March and September for TP and March for silicat, respectively.