Snake/Salt River Basin Plan - Basin Boundaries

Metadata also available as

Frequently-anticipated questions:

What does this data set describe?
    Title: Snake/Salt River Basin Plan - Basin Boundaries
    Abstract:
    This dataset contains displays the boundaries of the Snake/Salt River Basin Plan for Wyoming mapped at a 1:24,000 scale.
    Supplemental_Information:
    The dataset's original extent, coordinate system, and data format have been altered. The dataset has been clipped to the extents of the Snake/Salt 6th level hydrologic unit code watershed boundaries. The coordinate system has been changed to Lat/Long NAD 1927, and the data format has been converted from an ESRI coverage to an ESRI shapefile. These data alterations occurred in 2003 for use in the Wyoming Water Development Commission's Snake/Salt River Basin Plan

  1. How should this data set be cited?

    Wyoming Geographic Information Science Center, 20020328, Snake/Salt River Basin Plan - Basin Boundaries: Wyoming Geographic Information Science Center, University of Wyoming, Laramie.

    Online Links:

    • www.wygisc.uwyo.edu/clearinghouse/watershed.html

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -111.049393
    East_Bounding_Coordinate: -109.762491
    North_Bounding_Coordinate: 44.490697
    South_Bounding_Coordinate: 42.484139

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: Oct-1999
    Ending_Date: Mar-2002
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • G-polygon (1)
      • Label point (2687)
      • GT-polygon composed of chains (2687)
      • Point (4)
      • Label point (0)
      • Composite object (101)
      • Composite object (647)

    2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000000. Longitudes are given to the nearest 0.000000. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.400000.
      The flattening of the ellipsoid used is 1/294.978698.

  7. How does the data set describe geographic features?

    basin_ssdd27
    identifies Snake/Salt Basin Boundary (Source: n/a)

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    COUNTY2
    Internal node number for the beginning of an arc (from-node). (Source: ESRI)

    Whole numbers that are automatically generated.

    Cnt_COUNTY
    Internal node number for the end of an arc (to-node). (Source: ESRI)

    Whole numbers that are automatically generated.

    LPOLY#
    Internal node number for the left polygon. (Source: ESRI)

    Whole numbers that are automatically generated.

    RPOLY#
    Internal node number for the right polygon. (Source: ESRI)

    Whole numbers that are automatically generated.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    Funding for the Wyoming Watershed Boundary Datasete (WBD) was provided by the Wyoming Department of Environmental Quality (DEQ) and the US Bureau of Land Management (BLM). Representatives from the DEQ, BLM, National Resource Conservation Service (NRCS), and the US Geological Survey (USGS) contributed a substantial amount of time and salary towards quality review of the dataset. Additionally, completion of the WBD has involved an extensive collaborative effort between WyGISC and numerous representatives from the DEQ, BLM and individual Field Offices, NRCS and individual Conservation Districts, US Forest Service and individual Forests, the Wyoming State Engineer's Office and individual Water Divisions, the Wind River Indian Reservation Tribal Council, and adjacant state agencies.

  3. To whom should users address questions about the data?

    Wyoming Geographic Information Science Center
    c/o Wendy Berelson
    Assistant Research Scientist
    P.O. Box 4008
    Laramie, WY 82071-4008

    (307) 766-2735 (voice)
    (307) 766-2744 (FAX)
    berelson@uwyo.edu

    Hours_of_Service: 9:00-5:00
    Contact_Instructions: Please email questions and requests.

Why was the data set created?

How was the data set created?
  1. From what previous works were the data drawn?

    DRG-E (source 1 of 1)
    Beartooth Mapping, Red Lodge MT, 19990301, Enhanced Digital Raster Graphic.

    Online Links:

    • www.beartoothmaps.com

    Type_of_Source_Media: CD-ROM
    Source_Scale_Denominator: 24
    Source_Contribution:
    The DRG-Es are the digital representation of the USGS 7.5min quadrangles. They were used as a backdrop to do on-screen digitizing of the watershed boundaries at 1:24k scale

  2. How were the data generated, processed, and modified?

    Date: 29-Mar-2002 (process 1 of 4)
    1) Phase I - Draft Delineations at 1:100,000-scale a) In ArcInfo Using blind pass processing on the USGS National Elevation Dataset (NED) 5000 pixel catchments were created b) Using the guidelines for creating watersheds outlined in the Federal Standards the NED derived watersheds were aggregated using tools created in ArcView. Reference Data included 1:100,000-scale National Hyrodgraphy Dataset reach code and 100K Digital Line Graph Hydrography (Strahler Order) and existing linework from USFS, NPS and adjacent states. c) The aggregated watersheds were attributed using tools created in ArcView. The attributes include 4th level/8 digit, 5th level/10 digit and 6th level/12 digit hydrologic Unit Codes (HUC). Comments regarding necessary editing (e.g. pourpoint adjustment) were also added with tools. d) Edit and dissolve NED derived sheds on 5th and 6th level HUCs e) Draft boundaries were reviewed and edits suggested by the Interagency Hydrologic Unit Group, neighboring states and other cooperators. f) Edits were made to the draft boudaries g) The final draft boundaries were checked for size appropriateness, pour point locations, and HUC attribute according to the Federal Standards. 2) Phase II - 1:24,000-scale delineations a) Using the draft boudaries as a guide and the Digital Raster Graphics - Enhanced (DRG-E) as a background the 1:24,000-scale boudaries were digitized as a shapefile using head-up digitizing in ArcView. Digitizing usually occured zoomed in at 1:7,000-1:12,000-scale. The general watershed boundary delineation rules used to digitize the watershed boundaries include: 1) drawing boundaries perpendicular to contours, 2) never crossing a waterbody or where contours indicate the location of overland flow would go (except as a pourpoint) and 3) when delineating along a ridgetop the boundary would be located closer to the side of the ridge with the steepest gradient. It should be noted that while general rules of hydrology were used the location of boundaries is still somewhat subjective as the 1:24,000-scale DRG-E do not always provide enough information for identifying the location of the boundaries in such instances group consensus was used. HUC 14040106 was digitzed by the United States Geolgic Survey in Utah. All of the steps noted below were carried out on the line work completed by Utah. b) All 1:24,000-scale linework was reviewed internally and corrections made accordingly. c) 10% of the 1:24,000-scale linework was then reviewed by the Interagency Hydrologic Unit Group (IHUC). d) The shapefile was converted to a polygon coverage in ArcInfo e) Topology was created in Arc/Info using CLEAN a dangle length of 15 and a fuzzy tolerance of 0.000000001. The coverage was created using double precision. f) The draft 1:100,000-scale boundaries were converted to a polygon coverage and cleaned using defaults g) Attributes from the 100,000k draft were transfered to the 1:24,000-scale coverage using the PUT command h) Additional attributes were added using some extensions and scripts created in ArcView. These included the HucNamer extension, the downstream HUC tool, flow modification NHD query tool. i)The remaining attributes required by the Federal Standard were added by querying the appropriate data in ArcView.

    Person who carried out this activity:

    Wendy Berelson
    Wyoming Geographic Information Science Center
    Assistant Research Scientist
    P.O. Box 4008
    Laramie, WY 82071-4008
    USA

    307-766-2735 (voice)
    307-766-2744 (FAX)
    berelson@uwyo.edu

    Hours_of_Service: 9-5
    (process 2 of 4)
    Dataset copied.

    (process 3 of 4)
    Metadata imported.

    Date: 1905 (process 4 of 4)
    This shapefile was Clipped to the boundaries of the Snake/Salt River Basin and reprojected as part of the Wyoming Water Plan

  3. What similar or related data should the user be aware of?

    Wyoming Geographic Information Science Center, 2002, Wyoming Watershed Boundary Dataset: Wyoming Geographic Information Science Center, University of Wyoming, Laramie.

    Online Links:

How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?

    The accuracy of this data is dependent on the level of detail of the source material and the interprtation procedures for capturing that source. The primary limiting factor for the level of detail of the source is the scale (1:24,000) of the enhanced digital raster graphic (DRG-E). The map scale determines the level of content that may be extracted from the given source during digitization.

  2. How accurate are the geographic locations?

    The map was digitized from USGS 1:24,000-scale digital raster graphic base maps, with an inherited error of +/- 40 feet according to USGS National Map Accuracy Standards. Digitized line locations were held to the +/- 40 foot accuracy standards by ensuring that all lines were within a 12 meter buffer of where visual interpretion put the actual boundary. Any lines outside the buffer were corrected. It is estimated that the errors detected were less than 10%. It should be noted that while general rules of hydrology were used (i.e. water flows downhill), the location of boundaries is still somewhat subjective as the 1:24,000-scale DRG-E do not always provide enough information for identifying the location of the boundaries. In these instances group consensus was used. Please refer to the methods section for more details on watershed delineation rules. Unquantifiable errors may be associated with coordinate shift (fuzzy tolerance was set to 0.000000001 meters, double precision), dangle (set to 15 meters). The default was used for all other ArcEdit tolerances. It should be noted that the data was digitzed using NAD27 horizontal datum as that is the native datum of the digital raster geographics. The data was then projected to NAD83 horizontal datum as requested by the NRCS. If the Wyoming data is reprojected to nad83 and overlaid on the DRG-Es with the NAD83 DRG-Es it can be assumed that the boundaries will be off by less than 2 meters. As with the original DRGs, DRG-E is cast in the Universal Transverse Mercator projection and is referenced to the NAD27 datum. When the drg-es are used in the NAD83 datum the alternate world files only approximate the NAD83 by shifting the coordinates of the imagery. The total error introduced using this shift is less than 2 meters for all DRG-E imagery.

  3. How accurate are the heights or depths?

    N/A

  4. Where are the gaps in the data? What is missing?

    All fields for all polygons in the .pat are attributed. Some polygons in the Ncontrb_a field might have a 0 value. All fields for the lines in the .aat are attributed. The lines adjacent to the universal polygon are attributed with a 0 for the hu_level. These cannot be attributed until the adjacent states complete their linework at which point the hightest level of hydrologic unit can be determined.

  5. How consistent are the relationships among the observations, including topology?

    There are no unclosed polygons, intersections without nodes, or polygons without labels or with more than one label. Arc/Info's topological checking program CLEAN was used to correct intersections without nodes, identify unclosed polygons and remove duplicate lines with the same beginning and ending nodes. All sliver polygons were removed either using eliminate, merge or manually in ArcEdit.

How can someone get a copy of the data set?
Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints:
The distributor shall not be held liable for improper or incorrect use of this data, based on the description of appropriate/inappropriate uses described in this metadata document. It is strongly recommended that this data is directly acquired from the distributor and not indirectly through other sources which may have changed the data in some way. These data should not be used at scales greater than 1:24,000 for the purpose of identifying hydrographic watershed boundary feature locations in Wyoming. WyGISC (Wyoming Geographic Information Science Center) makes no claims for the data's suitability for other purposes. WyGISC should be acknowledged as the data source in products derived from these data. The Wyominig Watershed Boundary Dataset is public information and may be interpreted by all organizations, agencies, units of government, or others based on needs; however, they are responsible for the appropriate application of the data. Federal, State, or local regulatory bodies are not to reassign to the WyGISC or the Natural Resources Conservation Service any authority for the decisions they make. The Natural Resources Conservation Service will not perform any evaluations of these maps or purposes related solely to State or local regulatory programs. Photographic or digital enlargement of these maps to scales greater than that at which they were originally delineated can result in misrepresentation of the data. If enlarged, the maps will not include the fine detail that would be appropriate for mapping at the small scale. Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data from the source distributor.

  1. Who distributes the data set? (Distributor 1 of 1)

    Wendy Berelson
    Wyoming Geographic Information Science Center - Univ. of Wyoming
    P.O. Box 4008
    Laramie, WY 82071-4008
    USA

    307-766-2735 (voice)
    307-766-2744 (FAX)
    berelson@uwyo.edu

    Hours_of_Service: 9-5
    Contact_Instructions: please e-mail with data requests.
  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    The distributor shall not be held liable for improper or incorrect use of this data, based on the description of appropriate/inappropriate uses described in this metadata document. It is strongly recommended that this data is directly acquired from the distributor and not indirectly through other sources which may have changed the data in some way. These data should not be used at scales greater than 1:24,000 for the purpose of identifying hydrographic watershed boundary feature locations in Wyoming. WyGISC (Wyoming Geographic Information Science Center) makes no claims for the data's suitability for other purposes. WyGISC should be acknowledged as the data source in products derived from these data. The Wyominig Watershed Boundary Dataset is public information and may be interpreted by all organizations, agencies, units of government, or others based on needs; however, they are responsible for the appropriate application of the data. Federal, State, or local regulatory bodies are not to reassign to the WyGISC or the Natural Resources Conservation Service any authority for the decisions they make. The Natural Resources Conservation Service will not perform any evaluations of these maps or purposes related solely to State or local regulatory programs. Photographic or digital enlargement of these maps to scales greater than that at which they were originally delineated can result in misrepresentation of the data. If enlarged, the maps will not include the fine detail that would be appropriate for mapping at the small scale. Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data from the source distributor.

  4. How can I download or order the data?

Who wrote the metadata?
Dates:
Last modified: 17-May-2004

Metadata author:
Wendy Berelson
Wyoming Geographic Information Science Center at the University of Wyoming
Assistant Research Scientist
P.O. Box 4008
Laramie, WY 82071
USA

307-766-2735 (voice)
307-766-2744 (FAX)
berelson@uwyo.edu

Hours_of_Service: 8-5 (school year): 7:30-4:30 (summer)
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Metadata extensions used:

Generated by mp version 2.7.33 on Mon May 17 16:47:50 2004