Using Video Imagery to Study Coastal Change: Whidbey Island

Science Center Objects

From May of 2018 through November of 2019, USGS scientists collected imagery from video cameras overlooking the coast along a beach on Whidbey Island, Island County at the northern boundary of Puget Sound in western Washington.

    Wet sand on a beach has a little shallow water with rocks and boulders, coastal cliffs in background.

    View of beach on Whidbey Island, looking north.

    The study area has some of the highest rates of coastal bluff retreat in Puget Sound. In fact, towards the end of 2019, the cliff area where the cameras were installed showed signs of failure, so the cameras were removed.

    An interagency team led by the USGS is researching how extreme-storm water levels and waves affect bluff erosion and the movement of sediment along beaches. The video-based remote-sensing tools measured storm water levels, waves, currents, and beach, and bluff changes to property, infrastructure, and habitats. The data enabled scientists to examine sediment transport that affects habitats for valued juvenile salmon, forage fish, and shellfish. In particular, the research is evaluating the extent that waves and sediment modify habitat complexity and its role in wave runup as well as shellfish biomass and diversity. Ultimately, the research will help guide and improve numerical model predictions of coastal and habitat change associated with sea-level rise, storms, and waves to inform resilience planning.

    Every half hour during daylight hours, from May of 2018 through November of 2019, video cameras installed on the high coastal bluff collected snapshots and video for 10 minutes. Some examples of the imagery are shown here.

      Snapshot

      The snapshot is the first frame of the video, just like a standard photo.

      Timex (time-exposure) image

      A timex is a time-averaged image of all frames, smoothing away surface waves and determining the location of persistent wave-breaking (indicative of shallow sandbars).

      Variance image

      A “variance” image shows the standard deviation of pixel intensity throughout the video, and it is useful for determining how much variation or movement is occurring at a given location.

      Bright image

      A “bright” image shows the brightest pixel values throughout the video, useful for identifying the position of maximum wave run-up on the beach, position of all breaking waves, and sea-state.

      Dark image

      A “dark” image shows the darkest pixel values throughout the video, useful for tracking sediment plumes, tracking floating debris, and filtering out breaking waves.