U.S. flag

An official website of the United States government

icon-dot-gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

icon-https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

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

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.

Get Data and Metadata
Author(s) Andrew Stevens orcid, Guy R Gelfenbaum orcid, Jonathan Warrick orcid, Ian Miller, Heather Weiner
Publication Date 2019
Beginning Date of Data 2017-07-20
Ending Date of Data 2017-07-23
Data Contact
DOI https://doi.org/10.5066/P9AJ8ALB
Citation Stevens, A., Gelfenbaum, G.R., Warrick, J., Miller, I., and Weiner, H., 2019, Digital elevation models (DEMs) of the Elwha River delta, Washington, July 2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9AJ8ALB.
Metadata Contact
Metadata Date 2020-10-19
Related Publication
Citations of these data No citations of these data are known at this time.
Access public
License http://www.usa.gov/publicdomain/label/1.0/
Loading...
Harvest Source: Coastal and Marine Geoscience Data System
Harvest Date: 2025-01-22T04:21:20.072Z