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M.A. Uhrich

Publications and source records attributed to M.A. Uhrich.

3 recordsLinked to original sources
USGS1997

Conversion of environmental data to a digital-spatial database, Puget Sound area, Washington

Data and maps from the Puget Sound Environmental Atlas, compiled for the U.S. Environmental Protection Agency, the Puget Sound Water Quality Authority, and the U.S. Army Corps of Engineers, have been converted into a digital-spatial database using a geographic information system. Environmental data for the Puget Sound area,collected from sources other than the Puget SoundEnvironmental Atlas by different Federal, State, andlocal agencies, also have been converted into thisdigital-spatial database. Background on the geographic-information-system planning process, the design and implementation of the geographic information-system database, and the reasons for conversion to this digital-spatial database are included in this report. The Puget Sound Environmental Atlas data layers include information about seabird nesting areas, eelgrass and kelp habitat, marine mammal and fish areas, and shellfish resources and bed certification. Data layers, from sources other than the Puget Sound Environmental Atlas, include the Puget Sound shoreline, the water-body system, shellfish growing areas, recreational shellfish beaches, sewage-treatment outfalls, upland hydrography,watershed and political boundaries, and geographicnames. The sources of data, descriptions of the datalayers, and the steps and errors of processing associated with conversion to a digital-spatial database used in development of the Puget Sound Geographic Information System also are included in this report. The appendixes contain data dictionaries for each of the resource layers and error values for the conversion of Puget SoundEnvironmental Atlas data.

Open-File Report↗
USGS1995

Analysis of nutrient and ancillary water-quality data for surface and ground water of the Willamette Basin, Oregon, 1980-90

An analysis of historical water-quality data for surface and ground water collected in the Willamette and Sandy River Basins during the 1980-90 water years was performed. For surface water, most data were concentrated at sites on the main stem Willamette River or near the mouths of major tributaries. All seasons were represented. Data for nitrogen and phosphorus species were readily available, but simultaneously collected discharge measurements frequently were not. Seven primary sites were used for a quantitative analysis of nutrient data in surface water. At six of the seven primary sites, median concentrations of nitrite plus nitrate and total phosphorus were less than 0.5 milligrams per liter (mg/L) as nitrogen (N) and 0.1 mg/L as phosphorus (P), respectively. These concen- trations were lower than national median concen- trations for basins with similar land uses. At the Pudding River site, which received significant point-source and agricultural nonpoint-source inputs, median values for nitrite plus nitrate and total phosphorus were 1.4 mg/L as N and 0.2 mg/L as P, respectively. Nitrite-plus-nitrate concentrations at this site were seasonally dependent, with the highest concentrations occurring during winter. Forested sites had significantly lower water temperatures and nutrient concentrations than urban or agricultural sites. Evidence of diel variations in dissolved oxygen concentrations and pH values suggest that, at some sites, low dissolved oxygen concentrations may be a problem during early morning hours in the summer. Historical nutrient data for ground water were limited primarily to nitrate and nitrite-plus-nitrate determinations for wells completed in the basin-fill and alluvial aquifer. Nitrate and nitrite-plus-nitrate concentrations in this aquifer showed a weak inverse relationship with depth.

Water-Resources Investigations Report↗