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Seasonal Variation and Sources of Dissolved Nutrients in the Yellow River, China.

Gong Y, Yu Z, Yao Q, Chen H, Mi T, Tan J - Int J Environ Res Public Health (2015)

Bottom Line: Nutrient concentrations exhibited substantial seasonal and yearly variations.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.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Qingdao 266100, China. gongyaohh@163.com.

ABSTRACT
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.

No MeSH data available.


Temporal trends of dissolved nutrient ratios in the lower YR at Lijin, 2002 to 2004.
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ijerph-12-09603-f007: Temporal trends of dissolved nutrient ratios in the lower YR at Lijin, 2002 to 2004.

Mentions: Temporal plots in molar nutrient ratios reveal features not readily observed in plots of dissolved nutrient concentrations alone (Figure 7). Both DIN/DIP and DSi/DIN exhibit a strong discharge-related periodicity although over the majority of the period 2002–2004 these trends are inversed. The DIN/DIP generally peaks in about March to April whereas the DSi/DIN generally peaks in about July and August, or about 6 months apart in low discharge and high discharge periods respectively. Temporal trends for DSi/DIP are generally more attenuate, however, there is a more general correspondence with increasing discharge and DIN/DIP. The DIN/DIP and DSi/DIN peaks were shown in August or September (in 2002 and 2004), when the discharge was high. It was the result of the diffuse, point sources and weathering processes. The diffuse process was the most important factor for DIP, while the weathering processes for DSi.


Seasonal Variation and Sources of Dissolved Nutrients in the Yellow River, China.

Gong Y, Yu Z, Yao Q, Chen H, Mi T, Tan J - Int J Environ Res Public Health (2015)

Temporal trends of dissolved nutrient ratios in the lower YR at Lijin, 2002 to 2004.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555301&req=5

ijerph-12-09603-f007: Temporal trends of dissolved nutrient ratios in the lower YR at Lijin, 2002 to 2004.
Mentions: Temporal plots in molar nutrient ratios reveal features not readily observed in plots of dissolved nutrient concentrations alone (Figure 7). Both DIN/DIP and DSi/DIN exhibit a strong discharge-related periodicity although over the majority of the period 2002–2004 these trends are inversed. The DIN/DIP generally peaks in about March to April whereas the DSi/DIN generally peaks in about July and August, or about 6 months apart in low discharge and high discharge periods respectively. Temporal trends for DSi/DIP are generally more attenuate, however, there is a more general correspondence with increasing discharge and DIN/DIP. The DIN/DIP and DSi/DIN peaks were shown in August or September (in 2002 and 2004), when the discharge was high. It was the result of the diffuse, point sources and weathering processes. The diffuse process was the most important factor for DIP, while the weathering processes for DSi.

Bottom Line: Nutrient concentrations exhibited substantial seasonal and yearly variations.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.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Qingdao 266100, China. gongyaohh@163.com.

ABSTRACT
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.

No MeSH data available.