Metadata:
  Identification_Information:
    Citation:
      Citation_Information:
        Originator: Jessica D. DeWitt
        Originator: Peter G. Chirico
        Originator: Sarah E. Bergstresser
        Originator: Inga E. Clark
        Publication_Date: 2018
        Title: The Central African Republic Diamond Database (2018) - Watersheds of Large Rivers
        Geospatial_Data_Presentation_Form: GIS dataset
        Publication_Information:
          Publication_Place: Reston, VA
          Publisher: U.S. Geological Survey
        Online_Linkage: https://doi.org/10.5066/F7FB51T5
        Larger_Work_Citation:
          Citation_Information:
            Originator: Jessica D. DeWitt
            Originator: Peter G. Chirico
            Originator: Sarah E. Bergstresser
            Originator: Inga E. Clark
            Publication_Date: 2018
            Title: The Central African Republic Diamond Database – A Geodatabase of Archival Diamond Occurrences and Areas of Recent Artisanal and Small-scale Diamond Mining
            Geospatial_Data_Presentation_Form: On File Report
            Publication_Information:
              Publication_Place: Reston, VA
              Publisher: U.S. Geological Survey
    Description:
      Abstract: This vector GIS dataset contains polygons that delimit the watershed boundaries of 6th order streams in the Central African Republic. It was derived from the 30m Hydrologically Corrected Digital Elevation Model (DEM) of the Central African Republic using the tools in ArcGIS 10.4. In brief, this process entails calculation of flow direction and flow accumulation raster datasets from the DEM; classification of the flow accumulation raster into gridcells representing the location of a stream (based on the blue lines of the 1:250,000 Joint Operations Graphic for CAR); calculation of the Strahler Stream Order; reclassification of the stream raster to remove lower order stream segments (orders 1-5); calculation of a stream link raster, which entailed enumeration of the reclassified stream's intersections; and calculation of watershed areas based on the stream link raster and the flow direction raster. Details regarding these procedures can be found in DeWitt and others (2018).
      Purpose: The purpose of this dataset is to delimit the watershed boundaries of large rivers in the Central African Republic.
    Time_Period_of_Content:
      Time_Period_Information:
        Single_Date/Time:
          Calendar_Date: 2017
      Currentness_Reference: publication date
    Status:
      Progress: Complete
      Maintenance_and_Update_Frequency: None planned
    Spatial_Domain:
      Bounding_Coordinates:
        West_Bounding_Coordinate: 14.721679683312
        East_Bounding_Coordinate: 27.202148432813
        North_Bounding_Coordinate: 10.746539462399
        South_Bounding_Coordinate: 2.8987157288129
    Keywords:
      Theme:
        Theme_Keyword_Thesaurus: Alexandria Digital Library Feature Type Thesaurus
        Theme_Keyword: drainage basins
      Place:
        Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
        Place_Keyword: Central African Republic
    Access_Constraints: none
    Use_Constraints: Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
    Point_of_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Jessica D. DeWitt
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical
          Address: 12201 Sunrise Valley Dr.
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Voice_Telephone: 703-648-6926
        Contact_Electronic_Mail_Address: jdewitt@usgs.gov
    Data_Set_Credit: U.S. Department of State, U.S. Agency for International Development
  Data_Quality_Information:
    Attribute_Accuracy:
      Attribute_Accuracy_Report: No formal attribute accuracy tests were conducted
    Logical_Consistency_Report: No formal logical accuracy tests were conducted
    Completeness_Report: Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
    Positional_Accuracy:
      Horizontal_Positional_Accuracy:
        Horizontal_Positional_Accuracy_Report: No formal positional accuracy tests were conducted
      Vertical_Positional_Accuracy:
        Vertical_Positional_Accuracy_Report: No formal positional accuracy tests were conducted
    Lineage:
      Process_Step:
        Process_Description: This watershed dataset was derived from the 30m Hydrologically Corrected Digital Elevation Model (DEM) of the Central African Republic using the tools in ArcGIS 10.4. In brief, this process entailed calculation of flow direction and flow accumulation grids from the DEM; classification of the flow accumulation grid into cells representing the location of a stream, resulting in a 'streams raster'; calculation of the Strahler Stream Order for the stream raster; reclassification of the stream grid to include only high order streams (orders 6-9); calculation of a stream link grid, which entailed enumeration of the reclassified stream's intersections; and calculation of watershed areas based on the stream link grid and the flow direction grid. Details regarding these procedures can be found in DeWitt and others (2017).
        Process_Date: 2017
  Spatial_Data_Organization_Information:
    Indirect_Spatial_Reference: This dataset covers the extent of the Central African Republic
    Direct_Spatial_Reference_Method: Vector
  Spatial_Reference_Information:
    Horizontal_Coordinate_System_Definition:
      Planar:
        Map_Projection:
          Map_Projection_Name: Transverse Mercator
          Transverse_Mercator:
            Scale_Factor_at_Central_Meridian: 0.9996
            Longitude_of_Central_Meridian: 21.0
            Latitude_of_Projection_Origin: 0.0
            False_Easting: 500000.0
            False_Northing: 0.0
        Planar_Coordinate_Information:
          Planar_Coordinate_Encoding_Method: coordinate pair
          Coordinate_Representation:
            Abscissa_Resolution: 30.0
            Ordinate_Resolution: 30.0
          Planar_Distance_Units: METERS
      Geodetic_Model:
        Horizontal_Datum_Name: D_WGS_1984
        Ellipsoid_Name: WGS_1984
        Semi-major_Axis: 6378137.0
        Denominator_of_Flattening_Ratio: 298.257223563
  Entity_and_Attribute_Information:
    Detailed_Description:
      Entity_Type:
        Entity_Type_Label: CAR_Watersheds_order6_streams
        Entity_Type_Definition: Each row indicates a watershed polygon within Central African Republic
        Entity_Type_Definition_Source: All values in the dataset were calculated in ArcGIS 10.4
      Attribute:
        Attribute_Label: Area_km2
        Attribute_Definition: Area of the watershed polygon in square kilometers
        Attribute_Definition_Source: Area value calculated by ArcGIS 10.4
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 0.002192
            Range_Domain_Maximum: 17797.77362
            Attribute_Units_of_Measure: square kilometers
      Attribute:
        Attribute_Label: Shape_Length
        Attribute_Definition: length of the perimeter of the watershed polygon, in meters
        Attribute_Definition_Source: Length value auto-calculated by ArcGIS 10.4
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 237.992614
            Range_Domain_Maximum: 1492847.288358
            Attribute_Units_of_Measure: meters
      Attribute:
        Attribute_Label: Shape_Area
        Attribute_Definition: Area of the watershed polygon in square meters
        Attribute_Definition_Source: Length value auto-calculated by ArcGIS 10.4
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 2192.352385
            Range_Domain_Maximum: 17797773620.396732
            Attribute_Units_of_Measure: square meters
  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Jessica D. DeWitt
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical
          Address: 12201 Sunrise Valley Dr.
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Voice_Telephone: 703-648-6926
        Contact_Electronic_Mail_Address: jdewitt@usgs.gov
    Distribution_Liability: Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
    Technical_Prerequisites: This dataset is formatted as a feature class in an ESRI geodatabase. It requires the user to have geospatial software such as ESRI ArcGIS, Blue Marble Global Mapper, Que GIS, GRASS, or other GIS software.
  Metadata_Reference_Information:
    Metadata_Date: 20180405
    Metadata_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Jessica D. DeWitt
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical
          Address: 12201 Sunrise Valley Dr.
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Voice_Telephone: 703-648-6926
        Contact_Electronic_Mail_Address: jdewitt@usgs.gov
    Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
    Metadata_Standard_Version: FGDC-STD-001-1998
