Abstract: This data layer is a merging of the Yukon River ecoregion data for the Canadian Yukon only with Alaska ecoregion data for Norton Sound and the US Yukon and Kuskokwim rivers (USGS 1995). The USGS National Stream Quality Accounting Network (NASQAN) program studies the water quality of large rivers of the United States. From 2001 to 2005, NASQAN will study the water quality of the Yukon River. Located in Canada and Alaska, the Yukon River drains approximately 330,000 square miles and is the fourth largest watershed in North America. As part of this water quality study, a number of Geographical Information System (GIS) data sets are being created. [Edited by TG to add ecoregion names to the attribute table from values found in the metadata and the Canadian Ecological Framework (http://sis.agr.gc.ca/cansis/nsdb/ecostrat/index.html). Canadian Ecoregions in British Columbia were appended, they were missing from the NASQAN dataset. The dataset was then dissolved on the Ecoregion Name, primarily to consolidate cross-border regions.]

Purpose: The purpose of the GIS datasets of the Yukon River Basin is to provide scientists working on the Yukon River study the information needed to do basic spatial analysis.This GIS coverage is one of 16 coverages created for the Yukon study.

Supplemental: Procedures_Used Ecoregions of the Yukon River Basin were created by obtaining a statewide coverage of Alaska developed by Gallant and others (1995) and obtaining a Canadian coverage of ecoregions developed by the Ecological Stratification Working Group (1995). Once these two coverages were obtained, the ecoregions of the Yukon River Basin was created by clipping the coverages with the watershed boundary of the Yukon River Basin. The Alaska coverage and the Canadian coverages were then edgematched and joined. The ecoregions coverage of the Yukon River Basin was projected into an Albers Equal Area projection with the following parameters: Projection ALBERS Units METERS Datum NAD27 Parameters: 1st standard parallel 55 00 00 2nd standard parallel 65 00 00 Central meridian -154 00 00 latitude of projection's origin 50 00 00 false easting (meters) 0.0000 false northing (meters) 0.0000 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., 1 plate. Ecological Stratification Working Group, 1995, A national ecological framework for Canada: Hull, Ottawa, Agriculture and Agri-Food Canada and Environment Canada, Report and National Map, scale 1:7,500,000.

Publication Date: 20020522

Originator: Dan Long, Tim Brabets

Online citation: \\KODIAK\I$\ProjectData\USFWS_CGL\CGL_LG_Data.mdb

Bounding coordinates:
West: -168.092182
East: -129.177327
North: 69.077973
South: 58.626998

Place Keywords: Yukon River Basin, Alaska, Canada

Theme Keywords: Basin Boundary, NASQAN, Yukon River, Ecoregions

Geographic: GCS_North_American_1983

Attributes of: Ecoregions

Metadata date: 20090722