『Abstract
Dissolved and particulate samples were collected from the Changjiang
(Yangtze River) in April and September 2006 to determine the sources
and distribution of P species in the river system. Concentrations
of DIP, DOP and TP varied obviously throughout the basin, and
displayed short-term variability and seasonal change. The predominant
species of DTP was PO43-. The
concentrations of P are related to water discharge, suspended
particulate matter and anthropogenic influences. Based on the
study data, the nutrient and the sediment retention capacity of
the Three Gorges Reservoir (TGR) were quantified. The P species
structure has a significant change throughout the TGR. A mass
balance analysis revealed that the reservoir was temporarily acting
as a DOP source. Some long-term data for PO43-
concentration at the Datong station are presented. The PO43- level has increased in the last
three decades because of the increased use of chemical fertilizer.』
1. Introduction
2. Sampling and methods
3. Results
3.1. Hydrographic features
3.1.1. April 2006 cruise
3.1.2. September 2006 cruise
3.2. Phosphorus species and concentrations
3.2.1. April 2006 cruise
3.2.2. September 2006 cruise
4. Discussion
4.1. Comparison with other large world rivers
4.2. Flux estimate
4.3. The phosphorus retention by the TGD
4.4. Historical review of the nutrient regimes in the Changjiang
5. Conclusions
Acknowledgements
References