Annual estimates of water and solute export from 42 tributaries to the Yukon River

• Published in: Hydrological Processes
• Main Authors: Frederick, Zanden A., Anderson, Suzanne P., Striegl, Robert G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2011
• Subjects: Yukon; Subarctic; Yukon river
• Online Access: http://dx.doi.org/10.1002/hyp.8255; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhyp.8255; https://onlinelibrary.wiley.com/doi/pdf/10.1002/hyp.8255

Abstract Annual export of 11 major and trace solutes for the Yukon River is found to be accurately determined based on summing 42 tributary contributions. These findings provide the first published estimates of tributary specific distribution of solutes within the Yukon River basin. First, we show that annual discharge of the Yukon River can be computed by summing calculated annual discharges from 42 tributaries. Annual discharge for the tributaries is calculated from the basin area and average annual precipitation over that area using a previously published regional regression equation. Based on tributary inputs, we estimate an average annual discharge for the Yukon River of 210 km 3 year –1 . This value is within 1% of the average measured annual discharge at the U.S. Geological Survey gaging station near the river terminus at Pilot Station, AK, for water years 2001 through 2005. Next, annual loads for 11 solutes are determined by combining annual discharge with point measurements of solute concentrations in tributary river water. Based on the sum of solutes in tributary water, we find that the Yukon River discharges approximately 33 million metric tons of dissolved solids each year at Pilot Station. Discharged solutes are dominated by cations calcium and magnesium (5.65 × 10 9 and 1.42 × 10 9 g year –1 ) and anions bicarbonate and sulphate (17.3 × 10 9 and 5.40 × 10 9 g year –1 ). These loads compare well with loads calculated independently at the three continuous gaging stations along the Yukon River. These findings show how annual solute yields vary throughout a major subarctic river basin and that accurate estimates of total river export can be determined from calculated tributary contributions. Copyright © 2011. This article is a U.S. Government work and is in the public domain in the USA.