{
    "tag": 12474,
    "title": "Digital elevation models (DEMs) of the Elwha River delta, Washington, September 2014",
    "pubdate": "2016",
    "sername": null,
    "series_name": null,
    "issue": "DOI:10.5066\/F7P55KN0",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/pcmsc\/DataReleases\/ScienceBase\/DR_F7P55KN0\/ew14_sept_dem.faq.html",
    "format": null,
    "email": null,
    "descript": "This part of the data release presents a digital elevation model (DEM) derived from bathymetry and topography data of the Elwha River delta collected in September 2014. Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system to changes in sediment supply. The U.S. Geological Survey developed an integrated research program aimed at understanding the ecosystem responses following dam removal that included regular monitoring of coastal and nearshore bathymetry and topography. As part of this monitoring program, the USGS conducted a bathymetric and topographic survey in the Strait of Juan de Fuca on the Elwha River delta, Washington (USGS Field Activity Number 2014-649-FA). Bathymetry data were collected using two personal watercraft (PWCs), each equipped with single-beam echosounders and survey-grade global navigation satellite systems (GNSS). Topography data were collected on foot with GNSS receivers mounted on backpacks. DEM surfaces were produced from all available elevation data using linear interpolation.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Stevens, Andrew W.",
            "role": "Author"
        },
        {
            "name": "Gelfenbaum, Guy R.",
            "role": "Author"
        },
        {
            "name": "Warrick, Jonathan A.",
            "role": "Author"
        },
        {
            "name": "Miller, Ian M.",
            "role": "Author"
        },
        {
            "name": "Weiner, Heather M.",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "80",
            "name": "bathymetry",
            "scope": "The elevation of the earth's surface beneath a body of water, especially the ocean, typically determined by measurements of depth from the water surface."
        },
        {
            "thcode": 2,
            "code": "82",
            "name": "bathymetry measurement",
            "scope": "Means of determining the depth to the floor of a body of water, especially the ocean."
        },
        {
            "thcode": 2,
            "code": "2041",
            "name": "digital elevation models",
            "scope": "Gridded elevation, geographically referenced to the surface of the earth, as digital data"
        },
        {
            "thcode": 2,
            "code": "492",
            "name": "GPS measurement",
            "scope": "Determination of distance and location using instruments receiving signals from the Global Positioning System, a system of satellites for identifying earth locations."
        },
        {
            "thcode": 2,
            "code": "1176",
            "name": "topography",
            "scope": "Configuration of the land surface and sea floor."
        },
        {
            "thcode": 15,
            "code": "006",
            "name": "elevation",
            "scope": "Height above or below sea level, for example altitude, bathymetry, digital elevation models, slope, derived products, DEMs, TINs"
        },
        {
            "thcode": 23,
            "code": "22",
            "name": "Bathymetry and Elevation",
            "scope": "Includes measures of the height of a location above or below a reference surface. Bathymetry is the elevation of the Earth's surface beneath a body of water, especially the ocean, typically determined by measurements of depth from the water surface at mean lower low water. Distributions are topographic maps and bathymetric charts based on collected data and also include smoothed or gridded maps of bathymetry and elevation from observational data or other associated factors. Assessment data types include models of ecological value, economic value, or current rates of alterations due to erosion, accretion, climate change, and other stressors (for example, wetland habitat loss). Predictions are the results of models or projections of future distributions, values, or ecological impacts of bathymetry, including predicted changes due to natural and human forces such as erosion, deposition, sea-level rise, and dredging activities; predictions also include the results of scenario-based models of bathymetry changes under different management strategies."
        },
        {
            "thcode": 61,
            "code": "417",
            "name": "Global Positioning System (GPS) observations",
            "scope": "the use of satellite signals from the Global Positioning System to determine the precise location of a terrestrial receiver."
        },
        {
            "thcode": 61,
            "code": "404",
            "name": "single-beam echo sounder",
            "scope": "acoustic technique for determining sea-floor depth directly below the instrument platform."
        },
        {
            "thcode": 61,
            "code": "429",
            "name": "topographic mapping",
            "scope": "used for traditional cartographic methods that document the distribution and elevation of geographic and hydrographic features (and usually cultural features and administrative boundaries)."
        }
    ],
    "place_term": [],
    "image": [
        {
            "name": "https:\/\/www.sciencebase.gov\/catalog\/file\/get\/583e217ae4b0f0dc05ea548b?name=ew14_sept_dem_5m.png&allowOpen=true",
            "description": "image map showing 5-m resolution digital elevation model (DEM) of Elwha River delta, color-coded to show elevation"
        }
    ],
    "fan": [
        "2014-649-FA"
    ]
}