USGS Home
Contact USGS
Search USGS
Oregon Water Science Center
Home
Data
Studies
Publications/Media
Information
|
U.S Geological Survey
Oregon Water Science Center 2130 SW 5th Ave Portland, OR 97201 Phone: (503) 251-3200 Fax: (503) 251-3470 E-mail: info-or@usgs.gov ABOUT THE OREGON WSC
Podcasts Twitter
ONLINE DATAINFORMATION CENTERABOUT THE USGSUSGS IN YOUR STATEUSGS Water Science Centers are located in each state and territory.
|
USGS Oregon WSC Highlights
How Do Algae Contribute to the Tualatin River Ecosystem? Pediastrum, a floating colonial green alga. (Photograph by Kurt Carpenter, USGS). Algae like this one produce oxygen and are important to the ecological health of slow-moving rivers like the lower part of the Tualatin River. Phytoplankton (floating algae) in the Tualatin River of northwestern Oregon are critical for maintaining the river's dissolved oxygen levels in summer. During the low-flow summer period, nutrients and a long residence time typically combine with ample sunshine and warm water to fuel blooms of algae in the low-gradient, slow-moving lower river. Most algae in the lower part of the Tualatin River are the kind that drift with the water because the river is moderately deep and the bottom does not have the type of substrate needed for attached algae. Growth of algae occurs as if on a conveyor belt of streamflow, a dynamic system that is continually refreshed with inflowing water. Transit through the system can take as long as 2 weeks during the summer low-flow period. Production of oxygen by algae is important in offsetting oxygen depletion near the river bottom caused by decomposing organic matter from, primarily, the land. Low oxygen concentrations can harm aquatic life.
New Software Tool Helps Water Managers Assess Effects of Stream and Lake Level Changes on Adjacent Lands Drained wetlands in the Wood River Valley adjacent to Upper Klamath Lake (Photograph by Trish Roninger, U.S. Fish and Wildlife Service, 2007). The Shoreline Mangement Tool will allow managers to predict inundation patterns and depths resulting from lake-level changes. The Shoreline Management Tool is a geographic information system (GIS) based program developed to assist water- and land-resource managers in assessing the benefits and effects of changes in surface-water stage on water depth, inundated area, and water volume. Additionally, the Shoreline Management Tool can be used to identify aquatic or terrestrial habitat areas where conditions may be suitable for specific plants or animals as defined by user-specified criteria including water depth, land-surface slope, and land-surface aspect. The tool can also be used to delineate areas for use in determining a variety of hydrologic budget components such as surface-water storage, precipitation, runoff, or evapotranspiration.
How Does Naturally Occurring Organic Matter in the Clackamas River, Oregon, Relate to Disinfection By-Products in Drinking Water?
Plants, such as this green alga, are a source of organic carbon that can react with chlorinated disinfection chemicals during the drinking water treatment process to form disinfection by-products. These compounds can cause cancer and birth defects. (Photograph by Kurt Carpenter, USGS.) Disinfection by-products (such as chloroform) result from the chemical interaction of chlorinated disinfection compounds and carbon-based organic matter that occurs naturally in the source water. Some of these disinfection by-products can cause cancer or birth defects. Water managers would like to be able to identify the types of organic carbon that contribute disinfection by-product precursors in source water to assess the potential for future deterioration of river quality resulting from a wide array of organic-matter sources. Understanding the timing, sources, and composition of organic matter entering drinking-water intakes will help drinking-water suppliers develop source-water-protection programs, facilitate successful and cost-effective treatment strategies, and plan for future upgrades to treatment plants. The Clackamas River drains a large area east of Portland, Oregon. Land cover in the watershed is primarily forest, but also includes agricultural and urbanized areas. The |