While all of the other spatial datasets in this directory are shapefiles (sometimes converted from ArcInfo coverages), anad_strms is provided as both a shapefile, anad_strms.shp, and in its original form as a coverage, such that more advanced users may use the routed stream feature within this coverage. The following abstract was written for the coverage.
This is a routed stream coverage that can be used with the following event tables: anad_all.events (includes all anadromous species), anad_chin.events (chinook), anad_coho.events, anad_chum.events, anad_pink.events, anad_sock.events (sockeye), and anad_steel.events (steelhead). These tables can be used with the "Add route events" tool in Arcmap to show where each species occurs along the anad_strms routed stream network. The variable stream_code should be used as the linking route identifier between the streams and the event tables. Each event table includes the variable, USE, which indicates whether the stream reach is used for spawning, rearing, migration or spawning/rearing or simply present (no specific use identified).
Stream routes and event tables were created by Ecotrust using line and point coverages developed by the Alaska Department of Fish and Game's (ADFG). The underlying hydrography was derived from several sources including: Alaska Department of Natural Resources hydrography layer (1:63,360); USGS Digital Line Graph (DLG) hydrography data; USFS hydrography layers; and ADF&G stream and species information.
The Alaska Department of Fish and Game's (ADF&G) Anadromous Fish Streams coverage is derived from the ADF&G's GIS coverage's utilized to produce the Atlas to the Catalog of Waters Important for Spawning, Rearing or Migration of Anadromous Fishes (referred to as the "Atlas") and the Catalog of Waters Important for Spawning, Rearing or Migration of Anadromous Fishes (referred to as the "Catalog"). These data sets are provided for general reference and to aid users in generating various natural resource analyses and products. The coverage depicts the rivers, streams and lakes known to contain anadromous fish species within Alaska (from the mouth to the known upper extent of species usage). It incorporates hydrography and species distribution and use data from a variety of sources. Note that the ADF&G updates this dataset fairly regularly and that stream numbers, locations, extent of cataloged habitat or species utilization of a given stream may change from year to year.
Data contained within this coverage is current as of 8/20/2002 for the DRAFT 2002 revisions to the Atlas to the Catalog of Waters Important for the Spawning, Rearing or Migration of Anadromous Fishes and the Catalog of Waters Important for the Spawning, Rearing or Migration of Anadromous Fishes. This particular data layer is for the Southcentral Region of Alaska.
Original Purpose from ADF&G:
The Alaska Department of Fish and Game's (ADF&G) Anadromous Fish Streams coverage is derived from the ADF&G's GIS coverage's utilized to produce the Atlas to the Catalog of Waters Important for Spawning, Rearing or Migration of Anadromous Fishes (referred to as the "Atlas") and the Catalog of Waters Important for Spawning, Rearing or Migration of Anadromous Fishes (referred to as the "Catalog"). The Atlas and Catalog are used to specify the water bodies referred to in AS 16.05.870, for the protection of waters important for the spawning, rearing or migration of anadromous fishes. The paper Atlas and Catalog documents are adopted into law by reference under 5 AAC 95.010 of the Alaska Administrative Code.
These data are provided for general reference and to aid users in generating various natural resource analyses and products. They are not intended to supplant the paper Atlas and Catalog documents adopted under 5 AAC 95.010. The coverage depicts the rivers, streams and lakes, or parts of them that are known to contain anadromous fish species within Alaska (from the mouth to the known upper extent of species usage). Data includes arc hydrography for the specified portion of the streams and locational point data for the waterbodies with species and lifestage utilization attributes. It incorporates data from a variety of sources including: USGS Digital Line Graph (DLG) hydrography data; Alaska Department of Natural Resources hydrography layer; USFS hydrography layers; and ADF&G stream and species information from the "Catalog" and "Atlas" and agency field data. Information for updating the dataset are submitted annually by area biologist and other staff from state and federal agencies and the private sector.
Additional Work:
Charles Steinbeck at Ecotrust routed the ADF&G arc coverage using the ADF&G point coverage and extracted individual arc coverages for each individual anadromous species. Matthew Goslin at Ecotrust developed the event tables from the individual species arc coverages.
Users must assume responsibility to determine the usability of this data for their purposes. These data are provided for general reference and to aid users in generating various natural resource analyses and products. They are not intended to supplant the paper Atlas and Catalog documents adopted under 5 AAC 95.010. They should not be relied upon, nor used for making regulatory decisions regarding permitting needs pursuant to AS 16.05.870-.880 or 5 AAC 95.010; nor referenced as being such. Stream numbers, locations, extent of cataloged habitat or species utilization of a given stream may change from year to year. To determine if a permit is required under AS 16.05.870-.880 and 5 AAC 95.010, please contact the area office of the ADF&G Habitat and Restoration Division or consult the current revision of the Atlas to the Catalog of Waters Important for Spawning, Rearing or Migration of Anadromous Fishes, or the Catalog of Waters Important for Spawning, Rearing or Migration of Anadromous Fishes.
Attributes for the points and arcs within the coverage are complete. The "barrier" type points are not included in this draft coverage.
Positional accuracy is verified by visually comparing the source information against hard copy printouts and digital display of anadromous stream data on a computer. No accuracy assessment has been performed against real world positions. Some streams may appear as straight lines between the mouth (lower point) and the known upper extent of species usage (upper point) where streams are very short (< 1/8 mile) or the exact location of the channel is not known.
Polygon attributes contain the BLM index number, meridian, township, range, and section number for each section. This coverage is intended to geographically represent BLM's protracted sections for on-shore townships and DNR's protracted sections for off-shore townships, and is not capable of supporting survey quality area calculations.
Protracted section grids are available as ARC/INFO coverages, statewide and by individual meridian (single or double precision), and by individual 1:250,000 quadrangle (double precision). Section corner coordinates are also available in ASCII format in a variety of projections, by meridian. Refer to the order form, "Request for DNR GIS Data," available through the DNR Public Information Centers, to clarify prices and options.
The lines that connect the upper and lower points will appear as either straight lines between the points with additional vertices at connecting tributaries or as stream hydrography depending on the area of the state. Currently stream hydrography and species data exist for the Southeast, Southcentral and Southwest regions. The Western, Arctic, and Interior regions of the state are being completed under a current project however, within this data set, they are represented by straight lines and upper and lower points only.
Straight lines between stream points are automatically added and snapped to tributary streams at the time of digitizing the stream points. Where hydrography exists, it was taken from the best available source. At the time the EVOS area was done this was USGS 1:63,360 stream hydrography which was modified and updated by ADNR. Subsequent hydrography was added from USGS DLG files, USFS files, and ADF&G digitized hydro.