NASQAN National Stream Quality Accounting Network
In 2001, the NASQAN program entered a five-year special study phase. This effort included significantly decreased sampling in the Colorado and Columbia basins and redirected those resources to an intensive sampling program in the Yukon basin. All sampling in the Colorado and Columbia basins were discontinued except for one or two downstream index stations. In the Yukon basin, fixed-station monitoring to determine constituent fluxes was supplemented with a series of synoptic cruises. These synoptic cruises were designed to provide baseline data on organic-carbon dynamics in response to the melting of permafrost in the Arctic.
During this period, sampling continued mostly unchanged in the Rio Grande basin. In the Mississippi River Basin, the station on the Missouri River at Pierre, South Dakota, was moved to the Missouri River at Yankton, South Dakota. New stations were added at the Ohio River at Sewickley, Pennsylvania, and the Cumberland River at Smithland, Kentucky, in 2001. Four stations was added to the lower Mississippi and Atchafalaya River Basin in Louisiana later in the period (the Mississippi River at Baton Rouge in 2004, and the Mississippi River at Belle Chase, the Atchafalaya River at Morgan City, and Wax Lake Outlet at Calumet, in 2006).