Physiographic and Land Cover Attributes of the Puget Lowland and the Active Streamflow Gaging Network, Puget Sound Basin, Washington

Table 1. Physiographic and land use attributes compiled for the Puget Lowland, Puget Sound Basin, Washington.


[Description: Applies to analysis units, drainage area of streamflow gages, or drainage area of Regional Stream Monitoring Program (RSMP) sites. Abbreviations: km/km², kilometer per square kilometer; m, meter; m/m, meter per meter; m/yr, meter per year; NOAA, National Oceanic and Atmospheric Administration; CCAP, Center for Clean Air Policy]


Attributes	Description	Units	Source
Elev	Mean elevation1	m	National Elevation Dataset, 10 m resolution http://nationalmap.gov/ data_delivery/ned.html
Lowland	Fraction of drainage area in lowland, calculated only for streamflow gages	U.S. Environmental Protection Agency Ecoregions
Slope	Mean slope	m/m	Calculated from National Elevation Dataset
PPT	Mean annual precipitation of area	m/yr	Parameter-elevation Regressions on Independent Slopes Model climatology normals 1971–2000, 800 m resolution http://prism.nacse.org/
StreamDen	Length of streams divided by area	km/km2	National Hydrography Dataset, medium resolution (1:100,000) flowlines http://nhd.usgs.gov/
GeoAluv	Fraction of area where surficial geology is alluvium	Fraction	Hydrogeologic framework for the Puget Sound aquifer system (Vaccaro and others, 1998)
GeoCoarse	Fraction of area where surficial geology is coarse-grained, unconsolidated sediment	Fraction	Hydrogeologic framework for the Puget Sound aquifer system (Vaccaro and others, 1998)
GeoFine	Fraction of area where surficial geology is fine-grained, unconsolidated sediment	Fraction	Hydrogeologic framework for the Puget Sound aquifer system (Vaccaro and others, 1998)
GeoRock	Fraction of area where surficial geology is bedrock	Fraction	Hydrogeologic framework for the Puget Sound aquifer system (Vaccaro and others, 1998)
Forest	Fraction of area with deciduous, evergreen, or mixed forest (CCAP classes 9–11)	Fraction	NOAA Coastal Change Analysis Program (CCAP) 2006 land cover classification http://www.csc.noaa.gov/digitalcoast/data/ccapregional
Wet	Fraction of area with palustrine or estuarine wetlands (CCAP classes 13–18)	Fraction	NOAA Coastal Change Analysis Program (CCAP) 2006 land cover classification http://www.csc.noaa.gov/digitalcoast/data/ccapregional
Imperv	Mean percent impervious cover	Fraction	National Land Cover Dataset 2006 impervious cover classification http://www.mrlc.gov/nlcd2006.php
RoadDen	Length of roads divided by area	km/km2	U.S. Census Bureau http://www.census.gov/geo/maps-data/data/tiger-line.html

¹Elevation is distance above North American Vertical Datum of 1988 (NAVD 88).