Publications

This report documents sampling and analytical methods and presents field data from a second year of an ongoing study on the Klamath River from Link River Dam to Keno Dam in south central Oregon; this dataset will form the basis of a hydrodynamic and water quality model. Water quality was sampled weekly at six mainstem and two tributary sites from early April through early November, 2008

In response to concerns that excessive plant growth in the lower Yakima River in south-central Washington was degrading water quality and affecting recreational use, the U.S. Geological Survey and the South Yakima Conservation District conducted an assessment of eutrophication in the lower 116 miles of the river during the 2004-07 irrigation seasons (March - October). The lower Yakima...

This report addresses physical channel issues related to instream gravel mining on the Umpqua River and its two primary tributaries, the North and South Umpqua Rivers. This analysis constitutes a “Phase I” investigation, as designated by an interagency team cochaired by the U.S. Army Corps of Engineers, Portland District, and the Oregon Department of State Lands to address instream...

Restoring previously drained wetlands is a strategy currently being used to improve water quality and decrease nutrient loading into Upper Klamath Lake, Oregon. In this 2003-05 study, ground- and surface-water quality and hydrologic conditions were characterized in the Wood River Wetland. Nitrogen and phosphorus levels, primarily as dissolved organic nitrogen and ammonium (NH4) and...

Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including pesticides, gasoline hydrocarbons, solvents, personal care and domestic-use products, disinfection by-products, and manufacturing additives. In all, 56 compounds were detected in samples collected approximately monthly during 2003-05 at the intake for the Clackamas River Water...

The role of irrigation and artificial drainage in the hydrologic cycle and the transport of solutes in a small agricultural catchment in central Washington's Yakima Valley were explored using hydrologic, chemical, isotopic, age-dating, and mineralogical data from several environmental compartments, including stream water, ground water, overland flow, and streambed pore water. A...

Water samples for tritium/helium-3 age dating were collected from 12 shallow monitoring wells in the Portland basin, Oregon, in 1997, and again in 1998. Robust tritium/helium-3 apparent (piston-flow) ages were obtained for water samples from 10 of the 12 wells; apparent ages ranged from 1.1 to 21.2 years. Method precision was demonstrated by close agreement between data collected in 1997...

Loss of pyrethroid insecticides onto surfaces during sample collection can confound the interpretation of analytical and toxicity test results. Sample collection devices, container materials, and water matrix composition have a significant influence on the association of pyrethroids to container walls, which can be as high as 50 percent. Any sample collection method involving transfer...

The unexpected inundation of Caledonia Marsh, a previously drained wetland adjacent to Upper Klamath Lake, Oregon, provided an opportunity to observe nutrient release from sediments into the water column of the flooded area and the resulting algal growth. Three sites, with differing proximity to the levee breach that reconnected the area to Upper Klamath Lake, were selected for water...

Landslides and floods of lava and water tremendously affected the Columbia River during its long history of transecting the Cascade Volcanic Arc. This field trip touches on aspects of the resulting geology of the scenic Columbia River Gorge, including the river-blocking Bonneville landslide of ~550 years ago and the great late- Pleistocene Missoula floods. Not only did these events...

Knowledge of the environmental constraints on a pathogen is critical to predicting its dynamics and effects on populations. Batrachochytrium dendrobatidis (Bd), an aquatic fungus that has been linked with widespread amphibian declines, is ubiquitous in the Rocky Mountains. As part of assessing the distribution limits of Bd in our study area, we sampled the water column and sediments for...

We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation...