Identification_Information: Citation: Citation_Information: Originator: Wyoming Gap Analysis Publication_Date: 1996 Title: 1:100,000-scale Hydrography for Wyoming (enhandced DLGs) Geospatial_Data_Presentation_Form: map Publication_Information: Publication_Place: Laramie, Wyoming Publisher: Spatial Data and Visualization Center Online_Linkage: Description: Abstract: Hydrographic features for Wyoming at 1:100,000-scale, including perennial and intermittent designations and Strahler stream order attributes for streams. Does not include man-made ditches, canals and aqueducts. The data was originally produced by USGS, a Digital Line Graph (DLG) product, though this product was enhanced (edgematched, some linework and attributes corrected, stream order attribute added). The dataset is provided in ArcView shapefile format, as two shapefiles: one for polygon features (lakes/reservoirs) and one for line features (streams, rivers). Legend files (.avl) have been provided for ArcView users (lakes.avl, streams.avl) to describe the attribute coding. In addition to the standard DLG coding, the streams shapefile has two additional attributes: ORDER (strahler stream order, 1-7) and PERENNIAL (1=perennial stream, 2=intermittent stream). Purpose: The purpose of this data layer was to provide a base layer of water features at a statewide level for riparian/aquatic species distribution modeling for the Wyoming Gap Analysis project. However the data may also be used for a variety of other natural resources management/biological studies at the appropriate scale. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: unknown Currentness_Reference: publication date of the source data, USGS DLGs Status: Progress: complete Maintenance_and_Update_Frequency: unknown, as needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -111.36554566 East_Bounding_Coordinate: -103.78380412 North_Bounding_Coordinate: 44.99390988 South_Bounding_Coordinate: 40.94479444 Keywords: Theme: Theme_Keyword_Thesaurus: none Theme_Keyword: hydrography Theme_Keyword: streams Theme_Keyword: lakes Theme_Keyword: water features Theme_Keyword: stream order Theme_Keyword: digital line graphs Place: Place_Keyword_Thesaurus: none Place_Keyword: Wyoming Access_Constraints: none Use_Constraints: Wyoming only. This data should never be used a scale larger than 1:100,000. The data is only as accurate as the source maps it was produced from, and use is dependent on the date of the sources and quality at which they were produced. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Data Manager Contact_Organization: Spatial Data and Visualization Center Contact_Address: Address_Type: mailing address Address: Box 4008 University Station City: Laramie State_or_Province: Wyoming Postal_Code: 82071 Country: USA Contact_Voice_Telephone: 307-766-2751 Contact_Electronic_Mail_Address: n/a Hours_of_Service: 8:00 - 5:00 MST Browse_Graphic: Browse_graphic_file_name: hydro.gif Browse_graphic_file_description: example of perennial and intermittent hydrography Browse_graphic_file_type: gif Data_Set_Credit: United States Geologic Survey National Mapping Program, data source. Edgematching, corrections, ordering: Margo Herdendorf, Tom Kohley - Wyoming Gap Analysis project. Native_Data_Set_Environment: The data was created in and is stored in Arc/Info 7.0.4 software for Unix operating system. This dataset has both line (stream network) and polygon (lakes/reservoirs) topology. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: This product is directly derived from the USGS DLGs, which according to the National Mapping Program do not currently carry quantified accuracy statements. However, procedures used by the NMP to validate the attribute accuracy involve computerized checking of attribute codes against a table of valid codes to endure that each attribute in a file is valid for the category. A manual process involving proof plots is used to verify correct application of codes. The additional attribute added by Wyoming Gap Analysis, stream order, automatic generation by a ordering program. The coding was checked by displaying each order as a different color on screen, and special attention was paid to braided streams or other complicated areas of stream connection. The Strahler order attributes are correct only so far as the connectivity and completeness of the hydrographic network is represented due to generalizations at the 1:100,000-scale. Obviously, there will be differentiation in order at the larger 1:24,000-scale because of the more accurate representations of streams at that scale. Attributes were also checked by visual color displays for intermittent and perennial attributes, as well as natural vs. man-made (all ditches, canals and aqueducts were removed). One section of Wyoming should be noted in particular for incorrect attributing which was corrected by Wyoming Gap Analysis: streams in Weston county, particularly the Lance Creek 1:100,000 quadrangle, were incorrectly labeled as perennial when, according to USGS 1:24,000-scale topographic maps, they were actually intermittent streams. Some linear features were corrected where they were man-made ditches/canals but incorrectly labeled as natural streams (primarily in the Pinedale quadrangle). Approximately 12% of the 1,792 1:24,000-scale topographic maps for Wyoming were used to verify the 1:100,000-scale DLGS, however these quads were not statistically selected for verification but rather were selected to check areas that had already been identified as "problem areas". Quantitative_Attribute_Accuracy_Assessment: Attribute_Accuracy_Value: unknown Attribute_Accuracy_Explanation: none Logical_Consistency_Report: 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. Checks were not made for possible errors such as sliver polygons or duplicate lines missed by CLEAN, though if any such errors exist they are likely to be minor due to the topological tests performed on the raw DLG data by the USGS NMP. Completeness_Report: Some attributes may have a zero value because of the hierarchical nature of the DLG MAJOR and MINOR attributes (see the USGS National Mapping Program Digital Line Graphs Data Users Guide 2 for more details). The attribute added by Wyoming Gap Analysis, stream order, is complete for all linework (Arc/Info arc attribute table), line features being labeled as zero corresponding to water features which are not ordered, eg. lakes, ponds and reservoirs. It should be noted that Wyoming Gap Analysis identified the two Yellowstone National Park quadrangles in the northwestern corner of the state to be mapped in less detail than surrounding quadrangles, (not just in the DLG product, but also on the original USGS 1:100,000-scale paper topological maps). Apparently different decision rules were applied by the NMP in translating hydrography from the 1:24,000-scale down to the 1:100,000-scale for this region of the state, and the data for these two quads should be considered as incomplete in comparison to the level of detail mapped for adjacent areas. Positional_Accuracy: Horizontal_Positional_Accuracy: +/- 300 meters Horizontal_Positional_Accuracy_Report: The USGS NMP identifies these procedures used to qualify the positional accuracy of their DLG products: the data are either manually digitized using equipment with a resolution of 0.001 inch and an absolute accuracy of from 0.003 to 0.005 inch, or are scanned on an automatic device with a resolution of 30 points per millimeter, or 0.0013 inch. The positional accuracy of the data and complete- ness of the file are checked by visually comparing proof plots with the original stable-base source material. These proof plots are generated using automated drafting machines with a resolution of 0.001 inch and an absolute accuracy of from 0.003 to 0.005 inch. Wyoming Gap Analysis converted raw DLG data into Arc/Info format with a 2 meter fuzzy tolerance (minimum distance between coordinates). Wyoming Gap Analysis also performed manual edge-matching along boundaries of 1:100,000-scale quadrangles of the source DLG data in Arc/Info, any positional offsets less than or equal to 200 meters being snapped together by splitting the distance between the two arcs. Other editing performed by Wyoming Gap Analysis which may or may not have an effect on the positional accuracy included adding or moving arc vertices and adding or lengthening arcs to join existing features in the edge- matching process. Grain tolerance used in adding/editing arc vertices was < 50m. Approximately 12% of the 1,792 1:24,000-scale topographic maps for Wyoming were used to verify the 1:100,000-scale DLGS, however these quads were not statistically selected for verification but rather were selected to check areas that had already been identified as "problem areas", areas where its was not possible to determine how to connect streams along quadrangle edges by referring to the 1:100,000-scale maps alone. Lineage: Source_information: Source_Citation: Citation_Information: Title: Digital Line Graphs for Hydrography Originator: U.S. Geological Survey, National Mapping Program Publication_Date: 1994 Type_of_Source_Media: digital map Source_Scale_Denominator: 100000 Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_date: unknown Source_Currentness_Reference: unknown, based on source paper maps Source_Citation_Abbreviation: DLG Source_Contribution: base data source Process_step: Process_Description: Raw DLG data (optional format) for Wyoming was converted to Arc/Info format 1:62,000-scale quads with a 2 meter coordinate resolution (fuzzy tolerance). These quadrangles were then tiled together into 1:100,000-scale quadrangles. During the process of tiling the 1:100,000-scale quadrangles into a statewide coverage, checking was done for proper feature alignment along the edges of the quads (edgematching). Streams or other hydrographic features with a positional offset (edge mismatch) of less than or equal to 200 m were snapped together by splitting the difference between them. In certain areas, it was necessary to refer to USGS 1:24,000-scale topographic maps to correctly determine the method of joining arcs. Editing changes included snapping endpoints of arcs together, adding or moving arc vertices, and adding new arcs to join or lengthen existing features. All arc features representing canals, ditches, or other man-made features were removed. Label errors which were identified by visual comparisons with paper maps were corrected. Process_Date: 199501 Source_Used_Citation_Abbreviation: DLG Process_step: Process_description: Following edgematching and other corrections to the original DLG data, all natural linear features were ordered, by major drainage (the state wide data was divided into 7 different drainages: North Platte, Belle Fourche, Crow, Wind River/Bighorn, Snake, Bear, Yellowstone) using the Strahler ordering method. The direction of flow of natural hydrographic features was adjusted using the Arc/Info TRACE command to best approximate the direction of flow in the drainage and its basins. A Strahler- ordering fortran program developed by USGS hydrologist, K. Lanfear, was applied to assign stream orders based on directional flow within the drainage. In cases of wide rivers represented by shorelines (instead of a stream centerline), braided rivers or stream networks interconnected circularly, the ordering had to rectified by interactive checking and editing. Wetlands, lakes, ponds and terminal reservoirs are not ordered. Streams flowing into Wyoming from other states (North Platte and Bear River drainages) were ordered based on visual inspection of source streams on 1:100,000- scale USGS maps of adjacent states (Colorado and Utah). Following the ordering and checking process, the individual drainages were appended back into a statewide coverage. Process_Date: 199502 Source_Used_Citation_Abbreviation: DLG Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Point_and_Vector_Object_Count: 9402 SDTS_Point_and_Vector_Object_Type: String Point_and_Vector_Object_Count: 93623 SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains Point_and_Vector_Object_Count: 12131 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Lambert Conformal Conic Lambert_Conformal_Conic: Standard_Parallel: 33 Standard_Parallel: 33 Longitude_of_Central_Meridian: - 107.5 Latitude_of_Projection_Origin: 41 False_Easting: 0.00000 False_Northing: 0.00000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 1.0 Ordinate_Resolution: 1.0 Planar_Distance_Units: METERS Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: GRS1980 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: There are 9 attributes associated with each arc hydrographic feature, and 8 for each polygon (both a .AAT and .PAT exist for this coverage). The first 8 attributes, MAJOR and MINOR codes 1-4, are part of the standard hierarchical coding scheme of the DLGs. The MAJOR attributes 1 and 2 are coded as 50 or 0, 50 representing a hydrographic feature digitized by the USGS, and 0 representing a hydrographic feature digitized by Wyoming Gap Analysis project. The MINOR attributes 1,2,3 have a numeric code for each feature, for example 412 is the code for stream and 200 is the code for shoreline. Most features only have associated codes at the highest level, MINOR1. (MINOR 2 and 3 identify other codes; for instance a stream may also be labeled as intermittent in MINOR2 and labeled as a boundary for a wetland in MINOR3). The most common MINOR2 attribute is 610, identifying intermittent features. The attribute ORDER identifies the Strahler order for the stream, 1-7. Polygon labels do not have an ORDERattribute. Arcs identified as shorelines, wetland boundaries or terminalreservoir boundaries are labeled as ORDER = 0. The attribute PERENNIAL identifies whether a stream is perennial (1) or intermittent (2). Definitions of Minor1,2 and 3 codes are listed here and are also included in two INFO tables accompanying the Arc/Info coverage: WYHYDRO.LINE and WYHYDRO.POLY. These files can also serve as display look-up tables for Arcplot, since they include symbol colors for the COLOR lineset. Definitions for line attribute values (.AAT): >200=Shoreline >412=stream >605=right bank >606=left bank >420=wash >103=glacier boundary >201=man-made shore >406=dam or weir >202=closure line >203=indefinite shore (identifies high-water mark) >204=apparent limit >400=rapids >401=falls >610=intermittent (all else assumed perennial) Definitions for polygon attribute values (.PAT): >101=reservoir >103=glacier >105=inundation area >108=submerged area (due to dam-building) >109=sewage pond >110=tailings pond >111=marsh/wetland, >402=gravel pit >412=wide river (represented by left and right bank) >420=emphemeral wash >421=lake or pond. Entity_and_Attribute_Detail_Citation: n/a Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Data Manager Contact_Organization: Spatial Data and Visualization Center Contact_Address: Address_Type: mailing address Address: Box 4008 University Station City: Laramie State_or_Province: Wyoming Country: USA Postal_Code: 82071 Contact_Voice_Telephone: 307-766-2751 Contact_Electronic_Mail_Address: n/a Distribution_Liability: The distributor shall not be held liable for improper or incorrect use of this data, based on the description of appropriate/inappropriate used described in this metadata document. It is strongly recommended that this data is directly acquired from the distributor described above and not indirectly through other sources which may have changed the data in some way. This data was developed and is meant to be used at the 1:100,000-scale (or smaller scale) for the purpose of identifying hydrographic feature locations in Wyoming. makes no claims for the data's suitability for other purposes. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ARCE (Arc/Info export) Format_Version_Number: 7.0.4 Format_Version_Date: 1995 File_Decompression_Technique: Export file was created using defaults, no compression Transfer_size: 70.9 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: ftp.sdvc.uwyo.edu or http://www.sdvc.uwyo.edu/clearinghouse Access_Instructions: The data can be accessed online two different way: by anonymous ftp or by the world wide web. The anonymous ftp server is ftp.sdvc.uwyo.edu, and the data is stored in the /pub/gis directory. The WWW page is http://www.sdvc.uwyo.edu/clearinghouse. Instructions are provided on-line for downloading and importing the data. Online_Computer_and_Operating_System: Both the ftp and WWW server which this data is available from is a Silicon Graphics Challenge server, running the IRIX 6.2 UNIX operating system. Fees: No fees are required for downloading the data that is on-line. Some fees may be required to cover costs of tapes if data is required on tape media. Metadata_Reference_Information: Metadata_Date: 199805 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Margo Herdendorf Contact_Address: Address_Type: mailing address Address: Box 4008 University Station City: Laramie State_or_Province: Wyoming Postal_Code: 82071 Country: USA Contact_Voice_Telephone: 307-766-2751 Contact_Electronic_Mail_Address: meh@uwyo.edu Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: 19940608