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  • Digital elevation models (DEMs) of the Elwha River delta, Washington, July 2017

    Metadata Updated: March 22, 2021

    This portion of the USGS data release presents digital elevation models (DEMs) derived from bathymetric and topographic surveys conducted on the Elwha River delta in July 2017 (USGS Field Activity Number 2017-638-FA). Nearshore bathymetry data were collected using two personal watercraft (PWCs) and a kayak equipped with single-beam echosounders and survey-grade global navigation satellite systems (GNSS) receivers. Topographic data were collected on foot with survey-grade GNSS receivers mounted on backpacks. Positions of the survey platforms were referenced to a GNSS base station placed on a benchmark with known horizontal and vertical coordinates relative to the North American Datum of 1983 (CORS96 realization) and North American Vertical Datum of 1988. The final data were projected in Cartesian coordinates using the Washington State Plane North (meters) coordinate system. A total of 1,270,212 individual elevation points were collected within the survey area between July 20 and July 23, 2017. DEM surfaces were produced from all available elevation data using linear interpolation. Two separate DEMs were constructed. A DEM was produced that covered the entire survey area (approximately 511 ha) with 5-m horizontal resolution. A second DEM with 1-m resolution was produced that covered the river mouth and adjacent areas (approximately 131 ha). The DEMs were created by interpolating between measurements as much as 50 meters apart. For this reason, we cannot evaluate the accuracy of each point in the DEM, only the measurements it is based on. The estimated vertical uncertainties of the bathymetric and topographic measurements are 12 and 5 cm, respectively. Digital data files for each DEM are provided in ESRI ARC ASCII (*.asc) format.

    Access & Use Information

    License: No license information was provided.

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    Dates

    Metadata Date October 19, 2020
    Metadata Created Date March 22, 2021
    Metadata Updated Date March 22, 2021
    Reference Date(s) January 1, 2019 (publication)
    Frequency Of Update notPlanned

    Metadata Source

    Harvested from USGS-Harvest

    Graphic Preview

    image map showing 5-m resolution digital elevation model (DEM) of Elwha River delta, color-coded to show elevation

    Additional Metadata

    Resource Type Dataset
    Metadata Date October 19, 2020
    Metadata Created Date March 22, 2021
    Metadata Updated Date March 22, 2021
    Reference Date(s) January 1, 2019 (publication)
    Responsible Party U.S. Geological Survey, Pacific Coastal and Marine Science Center (Point of Contact)
    Contact Email
    Guid
    Access Constraints Use Constraints: USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data. This information is not intended for navigational purposes., Access Constraints: none
    Bbox East Long -123.520296
    Bbox North Lat 48.159538
    Bbox South Lat 48.135183
    Bbox West Long -123.591538
    Coupled Resource
    Frequency Of Update notPlanned
    Graphic Preview Description image map showing 5-m resolution digital elevation model (DEM) of Elwha River delta, color-coded to show elevation
    Graphic Preview File https://www.sciencebase.gov/catalog/file/get/5c9bf7bae4b0b8a7f62c32cb?name=ew17_july_dem_5m.png&allowOpen=true
    Graphic Preview Type PNG
    Licence Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
    Metadata Language eng; USA
    Metadata Type geospatial
    Progress completed
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 2017-07-20
    Temporal Extent End 2017-07-23

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