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T.S. McGrath

Publications and source records attributed to T.S. McGrath.

2 recordsLinked to original sources

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

Estimation of ground-water recharge from precipitation, runoff into drywells, and on-site waste-disposal systems in the Portland Basin, Oregon and Washington

The average recharge rate in the Portland Basin, in northwestern Oregon and southwestern Washington, is estimated to be about 22.0 inches per year. Of that amount, precipitation accounts for about 20.8 inches per year, runoff into drywells 0.9 inches per year, and on-site waste disposal about 0.4 inches per year. Recharge is highest, about 49 inches per year, in the Cascade Range. Recharge is lowest, near zero, along and between the Columbia and Willamette Rivers. Recharge is higher locally in discrete areas owing to recharge from runoff into drywells and on-site, waste-disposal systems in urbanized parts of the study area. In these urbanized areas, recharge ranges from 0 to 49 inches per year.

Water-Resources Investigations Report