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State of Oregon Study Area Abstract

The United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) is conducting a study in the western United States (EPA Regions 8, 9, and 10) that will advance the science of ecological monitoring and demonstrate techniques for regional-scale assessment of the condition of ecological systems.

Human pressures on the natural resources of the United States are intense. These pressures have resulted in many unintended changes in our ecosystems -- loss of biodiversity, increases in the number of endangered species (e.g. salmon), habitat degradation, and increases in contamination and pollution. Major public and private efforts have gone into controlling pollution, and protecting and restoring natural resources and the ecosystems they depend on. Corrective actions have and will continue to have an impact upon how we all lead our lives. We react to the problems that are most visible and thus receive the greatest amount of publicity. To make the most of our environmental efforts, we need to understand and assess the status and trends in the condition of our ecological resources and the stressors affecting these systems. It is not at all clear that we are currently targeting financial resources and/or lifestyle changes on problems or at locations where they will have the most effect.

To move toward an improved monitoring approach EPA has begun the Environmental Monitoring and Assessment Program (EMAP). EMAP is a research program that is used to develop the tools necessary to monitor and assess the status and trends of ecological systems. EMAP had its beginnings assessing the effects of acid deposition on large geographical areas of the U.S. during the 1980s. Out of that work came the concept of probability-based monitoring and the need for regional-scale assessments. EMAP's goal is to develop the scientific understanding for translating environmental monitoring data from multiple spatial and temporal scales into assessments of ecological condition.

The landscape component of the Western Pilot study provides information that has multiple management implications. Regional Landscape Atlases and Landscape Data Browsers will be provided to assess the spatial distribution of landscape stressors on aquatic ecosystems across each region. This will assist regional managers in understanding how landscape conditions contribute to varying aquatic resource conditions. As such, the atlases also will contribute to formulation of specific management actions for different geographic locations within each region. The first step in providing regional atlases will be to test and demonstrate landscape assessment methodologies on sub-regional areas of high importance to each Region.

State of Oregon Study Area

The State of Oregon is bounded by the Pacific Ocean on the west and the states of Nevada and California on the south, Washington on the north, and Idaho on the east. The study area includes all of Oregon and those portions of watersheds in Oregon which extend into each of the four states bordering it. In most cases, these "boundary watersheds" radiate out from Oregon less than 40 km (25 mi.) into its neighboring states; although, a few watersheds do reach considerably further into Nevada and Idaho. The overall study area encompasses approximately 333,281 km2 (128,681 mi2 ) and Oregon 251,415 km2 (97,072 mi2 ) in surface area.

Major landforms in the State of Oregon Study Area include the scenic headlands of the Coast Ranges, which are comprised predominantly of ancient volcanoes. To the east is the volcanically active Cascade Range, a region which includes the snow-capped and/or glaciated peaks of Mount Hood, Mount Jefferson, and the Three Sisters, and the deep caldera of Crater Lake and the national park which encompasses it. The Willamette Valley, a substantial catch basin which empties into the Columbia River, is situated between the Coast and Cascade ranges. The Columbia Plateau with its rugged scablands covers much of the eastern half of Oregon and extends into adjoining areas in Nevada, Idaho, and Washington. The Blue Mountains in the northeastern portion of the state is where placer and lode gold mines were active in the past. A significant part of the southeastern portion of the Oregon is contained within the Great Basin. This area, with its characteristic steep mountain ranges and high basins, is also categorized as being a part of the Basin and Range Province.

The land ownership in the coastal portions of the State of Oregon Study Area is predominantly a mix of private holdings and areas managed by either the USDA Forest Service (USFS), Bureau of Land Management (BLM), or the State of Oregon. To the east, most of the Willamette Valley is urban or is privately owned and used heavily for agriculture. The majority of the Cascade Range, which constitutes the geographic divide between eastern and western Oregon, is administered by the USFS and includes many wilderness areas, although the Warm Springs Indian Reservation is located in the northern part of these mountains, as well. The mountainous areas in the eastern half of Oregon are also primarily USFS-managed lands, while most of the lower-elevation plateau areas are agriculturally based private land, much of which supports vast dryland wheat farming and livestock ranching operations and, in the north, fruit orchards. Most of the southeastern portion of the state is under the administration of the BLM, but also includes expansive tracts maintained as national wildlife refuges.

The most prominent watercourse in the study area is lower Columbia River, which forms a significant stretch of the Oregon-Washington border and which flows into the Pacific Ocean. Major tributaries of the Columbia within the study area include the Snake River, which cuts through Hells Canyon National Recreation area and forms a large part of the Oregon-Idaho border, and the Willamette, Deschutes, and John Day rivers, all of whose watersheds are contained entirely within the State of Oregon. Many medium-sized, locally significant rivers such as the Nehalem, Siuslaw, Umpqua, Rogue, and their tributaries, wend their way through the Coast Ranges and empty directly into the Pacific Ocean. Annual precipitation in the study area varies greatly, from less than 250 mm (10 in.) to 4600 mm (180 in) or more; and elevations range from sea level on the coast to as high as 3426 m (11,239 ft) atop of Mount Hood. These diverse conditions provide the settings for environments which support an equally wide array of fauna and flora, as is witnessed by the fact that such biomes as that the semiarid "cold desert," chaparral, grasslands, hardwood forests, temperate rain forest, and subalpine and alpine communities all thrive within the study area.

Five main transportation corridors slice north-to-south through the study area, which from west to east, include: US Route 101, hugging the Pacific coastline; Interstate 5, traveling between the Cascade and Coast ranges; US Route 97, running along the eastern side of the Cascades; US Route 395, cutting through the Great Basin and Blue Mountains regions; and US Route 95 snaking along the Oregon-Idaho border. The two main east-west roads in the study area are Interstate 84, tracing the south bank of the Columbia River after angling through the northeastern corner of Oregon, and US Route 20, meandering through the center of the state. Many other smaller state and county roads weave throughout the study area, most of which connect to one or more of these major routes. The Pacific Crest National Scenic Trail also passes through the study area basically following the spine of the Cascade Range.

Approximately 3.5 million people reside within the State of Oregon, most of whom live in the cities and suburbs along or adjacent to Interstate 5, including Portland, Salem, Eugene, Albany, Corvallis, and Medford. There are also many smaller towns along the Pacific Coast on US Route 101, such as Lincoln City, Newport, and Coos Bay, as well as scores of state recreation areas and parks and the Oregon Dunes National Recreation Area. In addition, Pendleton is the hub in the northeast portion of the state and, in east-central Oregon, the City of Bend has experienced significant growth over the past few decades. And, with the exception of the suburban areas of Portland situated on the Washington side of the Columbia River, the border-state lands situated within the study area are, for the most part, sparsely populated. The economy of the study area is based most notably on the forest products, tourism, agriculture/livestock, and, in recent years, the electronics industries.


Geology of the Oregon Area

Inforain. Map: Northwestern Oregon Major Land Ownership.

Oregon State University. Oregon Climate Service. Average Annual Precipitation - Western United States. Spatial Climate Analysis Service, 2000.

State of Oregon. Oregon Department of Forestry.
http://www.odf.state.or.us Exit EPA Disclaimer


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General information on the State of Oregon Data Browser 

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