Yukon River Project
As part of the USGS NASQAN program the objective of this study is to establish a baseline describing the general water quality of the Yukon River and its major tributaries as a reference to measure future changes.Abstract
The U.S. Geological Survey conducted a five-year water quality study of a 3000 km reach of the Yukon River and its major tributaries from its headwaters in the Yukon Territory, Canada to Pilot Station, Alaska near its mouth and just above tidal influence. The objectives of the study are: 1) Establish a baseline describing the general water quality of the Yukon River and its major tributaries as a reference to measure future changes. This objective was achieved by sampling the Yukon River and two of its major tributaries at five fixed sampling sites approximately seven times from March through September during 2001-2005; 2) Identify processes that affect or control the water quality of the Yukon River and its tributaries. This objective was achieved by conducting intensive sampling campaigns at high flow in June and low flow in late August during 2002-2004. The first reach and its major tributaries from Eagle, Alaska, to the Dalton Highway were sampled during the summer of 2002. The second reach and its major tributaries from the highway to Pilot Station were sampled during the summer of 2003. The third reach and its major tributaries from Whitehorse, Canada, to Eagle were sampled during the summer of 2004. Along with discharge, a suite of geochemical parameters, including suspended sediment, quantitative mineralogy, major ions, trace elements and nutrients were measured with emphasis on dissolved and particulate carbon, gas flux and generation of methyl mercury. Discharge and water quality sampling using equal discharge increments provide instantaneous fluxes. In addition, the occurrence and fate of constituents of environmental concern, such as mercury and other toxic metals, were addressed. These data continue to be analyzed for current and future publications. The water quality of the Yukon River Basin (YRB), the fourth largest drainage basin in North America, is poorly documented and may be changing in response to warmer temperatures. Permafrost regions in the YRB are melting. As permafrost melts, the frozen soil is transformed into biogeochemically active zones. Runoff moving through and across these active zones is hypothesized to change the flux of solutes to Yukon tributaries and the main stem, ultimately changing the Yukon River water chemistry. Identification of the sources and sinks of the constituents listed above, in addition to the processes controlling their fate and reactivity, will provide an important frame of reference to assess water quality changes in the YRB that may result from permafrost melting and a warmer climate.
Products
| Title | Type |
|---|---|
| Yukon River Basin Studies | Project Website |
Contacts
Brabets, Timothy , 907-786-7105Status: completed
Start Year: 2000
End Year: 2015