Existing Conditions Datasets


Transportation - Ownership - Road Netwrok - GPS Points

Data sets that describe features constructed or influenced by humans such as land ownership patterns, roads, railroads, and coordinate positioning information are included in the cultural theme group. These themes were derived from a variety of existing sources including federal (e.g. US Forest Service, US Bureau of Land Management) and state (e.g. Oregon Department of Transportation, Oregon State Service Center for Geographical Information Systems) agency records or they were generated by the project as a result of fieldwork or analysis (e.g. Global Positioning System points of reference at road/railroad/stream crossings).


Block Group Age - Block Group Population - 1930 Population - 1970 Population - STF1A - STF1B - 1850 Population

This theme group contains data sets describing the human population of the Basin by geographical units such as counties,towns (named places), U.S. Census Bureau defined blockgroups, tracts, and places. Data consist of demographic statistics from the 1850, 1930, 1970 and 1990 U.S. Census. The census data shown provide information regarding population density, gender balance, and age.


Fifth Field Hydro Units - Lakes - Rivers - Watershed Boundary

The Hydrologic theme group includes delineations of the water bodies of the Willamette River Basin as well as the Fifth Field hydrologic unit codes (HUC's) used by the US Geological Survey to define hierarchic sub-units of the Basin across the area. Water bodies including rivers, lakes, and streams captured at various levels of spatial detail are also in this theme group.


Ecoregions - Geology - Soils (SSURGO and STATSGO) - 1850 Vegetation (preview only)

The physiographic theme contains data sets describing the physical geography of the project area by characteristics such as landform, elevation, biota and soils. There are data sets from previously compiled ecoregion classifications by the US Environmental Protection Agency and geological classifications by the US Geological Survey. The soils data sets were assembled from US Natural Resources Conservation Service sources and refined. Historic vegetation data were compiled by the Oregon Natural Heritage Program from General Land Office survey records. 


Topographic Aspect - Hillshade - Topographic Slope - Digital Elevation Model

The digital elevation model was compiled from US Geological Survey sources, and representations of topographic slope, aspect and shaded relief were generated from the digital elevation model of the Basin.

- LAND USE / LAND COVER ca. 1990 -

Land Use / Land Cover circa 1990 is a gridded representation of the landscape of the Willamette River Basin around 1990. Each 30 m cell describes a land cover or a land use. The former includes forest age and type, agricultural crops, and water features. The latter includes roads, railways, urban residential use (defined by four categories of household density), commercial and industrial uses, and rural structures. Multiple data sources were drawn from in order to construct this grid, and a priority scheme invoked to uniquely define each cell. This grid represents the initial conditions upon which possible future scenarios of development within the WRB are based.


 - Decompression Software -


The Oregon State Service Center for Geographic Information Systems provides free versions of decompression sofware.

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Last Update: Thursday, September 9, 1999