Study Area: Portland, Oregon

General Description:

The Portland study area is located in western Oregon and parts of Washington, USA. Major cities are Portland, Eugene, and Salem, Oregon. The population the Portland-Salem Metropolitan Area has increased 26.3 percent from 1990 to 2000 and was about 2.3 million people in 2000 (U.S. Census Bureau, 2000). The study area is in the Willamette Valley ecoregion (Omernik 1987), which is characterized as a broad, lowland valley with a mosaic of vegetation of rolling prairies, deciduous and coniferous forests, and extensive wetlands. Landforms consist of terraces and floodplains that are interlaced and surrounded by rolling hills. Agriculture (primarily grass seed crop) is the dominant land use in the region (Uhrich and Wentz 1999). Elevation of the study area ranges from about 0 to 4,364 feet (0 to 1330 meters) above sea level (U.S. Geological Survey, 2005). The climate is characterized by cool, wet winters and warm, dry summers with a mean annual temperature of 52 degrees Fahrenheit (11.1 degrees Celsius) and mean annual precipitation of 57 inches (145 centimeters)(Daymet, 2005). Most of the precipitation occurs between October and April. Highest flows occur from November to March and lowest flows occur in summer and fall. Streams in this region support warm-water biological communities.

Time of study:

Site selection in 2003, data collection from spring 2004 to fall 2004.

Study design:

Twenty eight sites were selected with drainage basin areas between 5 to 40 square miles (13 to 104 square kilometers) and had minimal natural variability among them. The land use gradient went primarily from agriculture to urban. Sites represented a broad range of urban intensity from low to high.

What urban looks like (maps and pictures)

Publications:

In Progress

Reference:
Daymet, 2005, Numerical Terradynamic Simultion Group: Univeristy of Montana, accessed December 2005, at http://www.daymet.org.

Omernik, J. M., 1987, Ecoregions of the conterminous United States: Annals of the Association of American Geographers v. 77, 118-125 p.

Uhrich, M.A., and Wentz, D.A., 1999, Environmental setting of the Willamette Basin, Oregon: U.S. Geological Survey Water Resources Investigations Report 97-4082-A, 20 p. http://or.water.usgs.gov/pubs_dir/Abstracts/97-4082a.html

U.S. Census Bureau, 2000, Census 2000 PHC-T-3, Ranking tables for metropolitan areas: 1990 and 2000, accessed January 2006, at http://www.census.gov/population/cen2000/phc-t3/tab03.pdf

U.S. Geological Survey, 2005, National Elevation Dataset (NED): U.S. Geological Survey, accessed December 2005, at http://ned.usgs.gov.

For more information about the study area
http://or.water.usgs.gov/projs_dir/pn366/nawqa.html