nawqa_ecoreg is a polygon coverage of the ecoregions contained in the Cook
Inlet National Water-Quality Assessment (NAWQA) study unit. This coverage was
developed by clipping a statewide coverage developed by Gallant and others in
1995 and is described in "Ecoregions of Alaska", USGS Professional Paper 1567.
The original coverage was published at 1:2,000,000. nawqa_ecoreg is in the
Albers Conical Equal Area projection and contains 51 polygons, 50 points, and
1899 strings.
The dataset was produced as a framework for organizing and interpreting environmental data. This coverage along with other coverages of the Cook Inlet NAWQA study unit will be used as a guide in designing the water-quality sampling scheme for the Cook Inlet Basin.
Procedures_Used:
nawqa_ecoreg was created by clipping the statewide coverage of ecoregions developed by Gallant and others in 1995. The boundaries of nawqa_ecoreg were clipped from the statewide coverage using the drainage basin boundaries of Cook Inlet defined by the statewide hydrologic unit code (HUC) map, developed at a 1:250000 scale by the USGS-WRD.
Revisions:
Reviews_Applied_to_Data:
Documentation review done by Roy Glass. Editorial review of documentation was done by Liska Snyder.
Related_Spatial_and_Tabular_Data_Sets:
Other_References_Cited:
Gallant, A.L., Binnian, E.F., Omernik, J.M., and Shasby, M.B., 1995, Ecoregions of Alaska: U.S. Geological Survey Professional Paper 1567, 73 p.
Notes:
Point_of_Contact USGS-WRD
Caution should be used when using the dataset at smaller scales.
USGS EROS field office, Anchorage, Alaska
In addition to the standard items found in the polygon attribute table, there are two added items - REGION and TRANSITION. REGION refers to the particular ecoregion:1-Alaska Peninsula Mountains; 15-Cook Inlet; 16-Alaska Range; 17-Copper Plateau; 19-Pacific Coastal Mountains; 20-Coastal Forests. TRANSITON refers to transitional areas: 1 is a transition area; 0 is not a transition area.