Seasonal Variation and Sources of Dissolved Nutrients in the Yellow River, China.
The rapid growth of the economy in China has caused dramatic growth in the industrial and agricultural development in the Yellow River (YR) watershed. The hydrology of the YR has changed dramatically due to the climate changes and water management practices, which have resulted in a great variation in the fluxes of riverine nutrients carried by the YR. To study these changes dissolved nutrients in the YR were measured monthly at Lijin station in the downstream region of the YR from 2002 to 2004. This study provides detailed information on the nutrient status for the relevant studies in the lower YR and the Bohai Sea. The YR was enriched in nitrate (average 314 μmol·L(-1)) with a lower concentration of dissolved silicate (average 131 μmol·L(-1)) and relatively low dissolved phosphate (average 0.35 μmol·L(-1)). Nutrient concentrations exhibited substantial seasonal and yearly variations. The annual fluxes of dissolved inorganic nitrogen, phosphate, and silicate in 2004 were 5.3, 2.5, and 4.2 times those in 2002, respectively, primarily due to the increase in river discharge. The relative contributions of nutrient inputs to nitrogen in the YR were: wastewater > fertilizer > atmospheric deposition > soil; while to phosphorus were: wastewater > fertilizer > soil > atmospheric deposition. The ratios of N, P and Si suggest that the YR at Lijin is strongly P-limited with respect to potential phytoplankton growth.
Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Qingdao 266100, China. gongyaohh@163.com.|Tianjin Marine Environmental Monitoring Center, State Oceanic Administration People's Republic of China, Tianjin 300450, China. gongyaohh@163.com.
Yao
Y
Gong
Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Qingdao 266100, China. zhigangyu@ouc.edu.cn.
Zhigang
Z
Yu
Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Qingdao 266100, China. qzhyao@ouc.edu.cn.
Qingzhen
Q
Yao
Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Qingdao 266100, China. chenht@ouc.edu.cn.
Hongtao
H
Chen
Key Laboratory of Marine Environment and Ecology, Ocean University of China, Qingdao 266100, China. mitiezhu@ouc.edu.cn.
Tiezhu
T
Mi
Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Qingdao 266100, China. Tsing112@sina.com.cn.
Jiaqiang
J
Tan
D002681:China; D004784:Environmental Monitoring / Q000379:methods; D009566:Nitrates / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis*; D010710:Phosphates / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D012621:Seasons; D017640:Silicates / Q000032:analysis*
D009566:Nitrates; D010710:Phosphates; D017640:Silicates; D010758:Phosphorus; D009584:Nitrogen
Yellow River; fluxes; nutrients; source