Bathymetry and topography data from the Elwha River delta, Washington, May 2012
Dates
Publication Date
2017-05-05
Start Date
2012-05-18
End Date
2012-05-20
Citation
Stevens, A.W., Gelfenbaum, G., Warrick, J.A., Miller, I.M., and Weiner, H.M., 2017, Bathymetry and topography data from the Elwha River delta, Washington, May 2012: U.S. Geological Survey data release, http://dx.doi.org/10.5066/F78G8HWT.
Summary
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 (USGS) developed an integrated research program aimed at understanding the ecosystem responses following dam removal. The research program included repeated surveys of beach topography, nearshore bathymetry, and surface sediment grain size to quantify changes in delta morphology and texture following [...]
Summary
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 (USGS) developed an integrated research program aimed at understanding the ecosystem responses following dam removal. The research program included repeated surveys of beach topography, nearshore bathymetry, and surface sediment grain size to quantify changes in delta morphology and texture following the dam removals. For more information on the USGS role in the Elwha River Restoration Project, please visit http://walrus.wr.usgs.gov/elwha/.
This USGS data release presents data collected during surveys of nearshore bathymetry and beach topography from the Elwha River delta, Washington. Survey operations were conducted between May 18 and May 20, 2012 (USGS Field Activity Number W-03-12-PS). The survey team included scientists from the U.S. Geological Survey Pacific Coastal and Marine Science Center (PCMSC), Washington State Department of Ecology (WA DOE), Oregon State University (OSU), San Jose State University (SJSU), and Washington Sea Grant (table 1).
Nearshore bathymetry data were collected using two personal watercraft (PWCs), each equipped with single-beam echosounders and survey-grade global navigation satellite system (GNSS) receivers. Topography data were collected on foot with GNSS receivers mounted on backpacks. Positions of the survey platforms were referenced to a GNSS base station placed on a nearby benchmark with known horizontal and vertical coordinates. Depths from the echosounders were computed using sound velocity profiles measured with a conductivity-temperature-depth (CTD) sensor during the survey. A total of 130 km of nearshore bathymetric survey lines and 120 km of topographic survey lines were collected during the 3 days of survey operations. Environmental conditions were favorable, resulting in good coverage of the beach and nearshore region. Figure 1 (top) shows the locations of bathymetric- and topographic-survey lines, CTD samples, and GNSS base stations. A continuous DEM surface of the primary survey area was produced from all available bathymetry and topography data using linear interpolation and a grid-spacing of 5 m. Figure 1 (bottom) shows the bathymetry and topography data for areas adjacent to the river mouth color-coded by elevation. An additional DEM with 1-m resolution grid-spacing was produced using linear interpolation for this smaller region.
Digital files containing the nearshore bathymetry data, beach topography data, and derived DEMs from this survey are available for download from the child item pages listed below.
Table 1. List of survey personnel
Person
Title
Affiliation
Guy Gelfenbaum
Research Oceanographer
USGS PCMSC
Andrew Stevens
Oceanographer
USGS PCMSC
Jeff Wood
Faculty Research Assistant
OSU
Heather Weiner
Coastal Geomatics Specialist
WA DOE
Rebecca Sexton
Field Technician
WA DOE
Brittany Johnson
Volunteer
SJSU
Ian Miller
Coastal Hazards Specialist
Washington Sea Grant
Figure 1. Top: Map showing locations of bathymetric- and topographic-survey lines, CTD casts, and GNSS base stations from the May 2012 survey of the Elwha River delta, Washington. Bottom: Zoomed in detail of top map showing bathymetric- and topographic-survey lines color-coded by elevation.
Click on title to download individual files attached to this item.
ew12_may_coverage.png “Image (.PNG)”
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Purpose
Data were obtained to assess the coastal geomorphic response following the removal of two dams on the Elwha River. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to identify topographic and shallow-water bathymetric features.