This archive includes annual and bi-annual image sets collected on the intertidal beach of the Elwha River delta in Washington State, USA during 18 distinct surveys between 2011 and 2023.  This period spanned the removal of two large dams on the Elwha River, that led to morphologic changes on the river's delta and adjacent shorelines (Warrick and others, 2019).  The images in this archive were collected coincident with topography and bathymetry surveys of the Elwha River delta (Stevens and others, 2025), and provide a photographic record of substrate changes associated with the topobathymetric evolution of a mixed sand and gravel delta. These digital images were collected along transects to support automated ‘digital grain size analysis’ (following, for example, Warrick and others, 2009), or substrate classification.

The collection of this dataset was supported with funding from the US Geological Survey and Washington Sea Grant. These data were collected in part on the lands of the Lower Elwha Klallam Tribe, and the collection of these images could not have been implemented without the support and authorization (through an access and research permit) of the Tribe. Additional field, logistical and project support has been provided by Jon Warrick (USGS), Dan Buscombe (Washington Department of Ecology, and formerly a USGS contractor), Matt Beirne (Lower Elwha Klallam Tribe), Cal Schurman (UW), Sam Alampay (UW), Christie Hegermiller (UW), Jackson Currey (USGS), Jon Felis (USGS), Brittany Johnson, Chris Clark, Vivian Leung, Kevin Simans, Tara McBride, Eliza Dawson, Amy Waeschle, Jacob Melly, Karsten Turrey, Bethany Nagid, Silsa Schiera, Jacob Carelson, Nancy Bluestein-Johnson (WWU), Emily Portillo, Wei Ying Wong, Zachary Levitan, George Kaminsky (Washington Department of Ecology), and Gabby Alampay (Landau Associates, formerly at Washington Department of Ecology). 

Images were collected bi-annually or annually during 18 distinct surveys occurring between May 2011 and August 2023. During each survey, images were collected along a set of transects (see table below) oriented perpendicular to the orientation of the shoreline. On each transect, images were collected between the water line, typically below the local mean lower low water tidal datum, and the upper intertidal zone where either vegetation or large wood entirely covered sediments from view. Images were collected typically using a horizontal spacing scheme, with more frequent sampling (a photo collected every 1-2 meters of horizontal distance is common) of the active beach face and areas of substrate change, and wider horizontal spacing between photos (a photo collected every 5-10 meters) on flatter and more uniform lower intertidal zones and back-shore areas. Sampled transects were primarily to the east of the Elwha River mouth, spaced approximately 250 m apart. The archive does include images from two transects located to the west of the Elwha River mouth.  There is variation in the number of transects sampled (median = 14, range = 5-17), and the density of photos collected on those transects, over the 18 distinct surveys included in this archive. The total number of photos collected during each distinct survey varies between 137 and 719 (mean = 430).  There are 7735 beach surface images in the archive.

Photos were collected using point-and-shoot style digital cameras hand-held above and pointed towards the beach surface.  In general, the camera was held approximately 50-100 cm above the beach surface: distances close enough to the bed to resolve individual grains of sand, gravel and other sediment fractions, while also sampling a substrate area adequate for estimating grains size sample statistics (see Warrick and others, 2009). Specific information about the camera model used for each image is available in the EXIF data. All images include a scale of some type. A high-accuracy location and elevation for every sample was collected next to the ground scale in each image using differential GPS operating in real-time kinematic mode, and is assumed to have horizontal and vertical accuracies of less than 10 cm.

A user may also find latitude and longitude from the camera's GPS chip embedded in the EXIF data associated with some photos, but the locations and elevations found in the survey data file included in each folder are more accurate and precise estimates of the location and elevation of the photo.  

In addition to the beach surface images, oblique images collected typically at the top and bottom of each transect sampled during each distinct survey are compiled into a single folder in this archive. No RTK-DGPS locations and elevations were collected for these images, though some may include locations in the EXIF data associated with the image. Oblique image file names include a reference to a transect number (see table below) on which the photos were collected, as well as the date that the photo was collected.  

A single data file is included with the collection of photos from each survey, with the following format:

·         Column 1, heading “File_Name”, is the file name of an individual image file in the folder

·         Columns 2-3, heading “Easting_m” and “Northing_m”, are the x and y coordinates of the sample location, in Washington State Plane, Zone North, metric coordinates

·         Column 4, heading “Elevation_NAVD88_m”, is the elevation of the sample, in meters, relative to the North American Vertical Datum of 1988. Various geoids were used between 2011 and 2023, but no correction was made to account for different geoids in the reported elevations at this site. Overall, this difference amounts to, at most < 2 cm.

·         Column 5-6, heading “Latitude” and “Longitude”, are the latitude and longitude of the sample location, in decimal degrees

·         Columns 6-7, heading “Date” and “Time”, are the date and time of collection of the survey point, referenced to Pacific Standard Time/Pacific Daylight Time.

·         Columns 8+, no heading, any addition columns that appear in these files are quality attributes output by the GNSS system used during the survey.  They vary by survey but can include estimates of the horizontal (HRMS) and vertical (VRMS) error estimate of the position and elevation, the RTK status (ie “fixed” vs “float”) and the number of satellites that contributed to the GNSS observation. 

References and Related Publications

Stevens, A.W., Gelfenbaum, G.R., Warrick, J.A., Miller, I.M., and Weiner, H.M., 2025, Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, July and August 2023: U.S. Geological Survey data release, https://doi.org/10.5066/P1BGEMN5.

Warrick, J.A., Stevens, A.W., Miller, I.M. et al. World’s largest dam removal reverses coastal erosion. Scientific Reports 9, 13968 (2019). https://doi.org/10.1038/s41598-019-50387-7

Warrick, J.A., Rubin, D.M., Ruggiero, P., Harney, J.N., Draut, A.E. and Buscombe, D. (2009), Cobble cam: grain-size measurements of sand to boulder from digital photographs and autocorrelation analyses. Earth Surf. Process. Landforms, 34: 1811-1821. https://doi.org/10.1002/esp.1877