Metadata
  Identification_Information:
    Citation:
      Citation_Information:
        Originator: U.S. Geological Survey
        Originator: U.S. Environmental Protection Agency
        Title: National Hydrography Datatset - High resolution
        Publication_Information:
          Publication_Place: Reston, Virginia
          Publisher: U.S. Geological Survey
    Description:
      Abstract:
        The high resolution National Hydrography Dataset (NHD) is a
        feature-based database that interconnects and uniquely
        identifies the stream segments or reaches that make up the
        nations surface water drainage system. High resolution NHD adds
        detail to the original 1:100,000-scale NHD. (Data for Alaska,
        Puerto Rico and the Virgin Islands was developed at high-
        resolution, not 1:100,000 scale.) Like the 1:100,000-scale NHD,
        high resolution NHD contains reach codes for networked features
        and isolated lakes, flow direction, names, stream level, and
        centerline representations for areal water bodies. Reaches are
        also defined to represent waterbodies and the approximate
        shorelines of the Great Lakes, the Atlantic and Pacific Oceans
        and the Gulf of Mexico. The NHD also incorporates the National
        Spatial Data Infrastructure framework criteria set out by the
        Federal Geographic Data Committee.
      Purpose:
        The NHD is a national framework for assigning reach addresses
        to water-related entities, such as industrial discharges,
        drinking water supplies, fish habitat areas, wild and scenic
        rivers. Reach addresses establish the locations of these
        entities relative to one another within the NHD surface water
        drainage network much like addresses on streets. Once linked to
        the NHD by their reach addresses, the upstream/downstream
        relationships of these water-related entities--and any
        associated information about them--can be analyzed using
        software tools ranging from spreadsheets to geographic
        information systems (GIS). GIS can also be used to combine NHD-
        based network analysis with other data layers, such as soils,
        land use and population, to help understand and display their
        respective effects upon one another. Furthermore, because the
        NHD provides a nationally consistent framework for addressing
        and analysis, water-related information linked to reach
        addresses by one organization (national, state, local) can be
        shared with other organizations and easily integrated into many
        different types of applications to the benefit of all. The
        National Hydrography Dataset is designed to provide
        comprehensive coverage of hydrologic data for the U.S. For this
        reason, the NHD initially was based on 1:100,000-scale data,
        but designed to encourage the development of this higher-
        resolution data. The development of the high resolution NHD is
        the culmination of a process that began with the merger of USGS
        DLG and EPA RF3 to create the NHD. The overall development
        process was designed as an evolutionary one, so that the
        qualities of DLG and RF3 would be retained, and the working
        characteristics of the NHD would be familiar to DLG and RF3
        users. This is true now with high resolution NHD which brings
        the benefits of higher resolution data to the established 1:
        100,000-scale NHD. The high resolution NHD will improve the
        integration of water-related data to support the application
        requirements of a growing national user community and will
        enable shared maintenance and enhancement. Similarly, high
        resolution NHD provides richer detail while carrying forward
        all of the components of the initial 1:100,000 NHD.
    Status:
      Progress: In Work
      Maintenance_and_Update_Frequency: Irregular
    Spatial_Domain:
      Bounding_Coordinates:
        West_Bounding_Coordinate:   -124.7333
        East_Bounding_Coordinate:   -67.9500
        North_Bounding_Coordinate:   49.3833
        South_Bounding_Coordinate:   24.5333
    Keywords:
      Theme:
        Theme_Keyword_Thesaurus:
          U.S. Department of the Interior, U.S. Geological Survey,
          1999, Standards for National Hydrography Dataset
          (http://mapping.usgs.gov/standards/)
        Theme_Keyword: Hydrography
        Theme_Keyword: Stream / River
        Theme_Keyword: Lake / Pond
        Theme_Keyword: Canal / Ditch
        Theme_Keyword: Reservoir
        Theme_Keyword: Spring / Seep
        Theme_Keyword: Swamp / Marsh
        Theme_Keyword: Artificial Path
        Theme_Keyword: Reach
      Place:
        Place_Keyword_Thesaurus:
          U.S. Department of Commerce, 1977, Countries, dependencies,
          areas of special sovereignty, and their principal
          administrative divisions (Federal Information Processing
          Standards 10-3): Washington, D.C., National Institute of
          Standards and Technology.
        Place_Keyword: US
    Access_Constraints: None
    Use_Constraints:
      None. Acknowledgment of the originating agencies would be
      appreciated in products derived from these data.