Landscape Data 
The Yaquina landscape analysis was done as part of a larger Pacific west coast estuary 
survey. Watershed boundaries subtending the Yaquina estuary basin were primarily determined 
from the Sixth Field hydrologic unit code (HUC) geospatial layer created by the Forest Service 
from 1:24,000 scale USGS maps, digital elevation models and other data sources. 
( http://www.reo.gov/gis/proiects/watersheds/REOFIUCvl 3.htm ) was used as a primary 
reference. In Oregon, the Forest Service and Oregon State University have produced a 
watershed layer refined to the 7th field HUC boundary lines for most of coastal Oregon 
(h ttp:// www. fsl. orst. edu/c lam s/cfs1023 3. h tm 1 ) north of the Rogue River-Refinements to the 
drainage boundaries between coastal and estuarine basins were often based on review of the 
hydrologic drainage patterns derived from digital elevation data (10 meter resolution in Oregon) 
and from USGS 1:24,000 scale quadrangle maps. Boundary lines and water bodies were plotted 
and reviewed for accuracy of coding and fidelity to the original sources. The Yaquina watershed 
delineated in this project captures the entire drainage area (EDA). By delineating the entire 
watershed, the watershed area is equivalent to the sum of NOAA’s Estuarine Drainage Area 
(EDA, portion of watershed that empties directly into the estuary and is affected by tides) and 
Fluvial Drainage Area (FDA, portion of an estuary's watershed upstream of the EDA boundary; 
see http://spo.nos.noaa.goV/proiects/cads/description.html#cafj . 
Land Cover Sources 
The estuary watershed was used as clipping boundaries for several land use/land cover 
datasets that are available for the Pacific coastal region at this time. The National Land Cover 
Data (NLCD, http://www.mrlc. govj represents land cover circa 1992 and its extent is 
nationwide. This dataset was clipped to the Yaquina watershed boundary. The 1992 NLCD data 
contains 21 classes of land cover (see http://erg.usgs.gov/isb/pubs/factsheets/fslQ800.pdfj . The 
area of each land cover class in square kilometers and as a percentage of the watershed was 
calculated and entered into an Access database. 
Two additional land use datasets have been created by the NOAA’s Coastal Services Center (C- 
CAP, http://www.csc.noaa.gov/crs/1 ca/ccap.htm 1 j program. The more recent data were derived 
from late 2000 and 2001 Landsat TM (thematic mapper) imagery. NOAA also produced a layer 
from imagery collected circa 1995-1996 and the earlier dataset was used to generate a land cover 
148 
