Video Remote Sensing of Coastal Processes

Science Center Objects

Video observations of the coast are used to monitor a range of coastal processes, for example changes in the shoreline position, both seasonally and due to long-term effects such as sea-level rise, and instances of beach and dune erosion during extreme storm events. 

The USGS National Assessment of Coastal Change Hazards project is using video remote sensing to collect observations that will improve our understanding of coastal change. Video observations of the coast can be used to monitor a range of coastal processes, for example changes in the shoreline position, both seasonally and due to long-term effects such as sea-level rise, and instances of beach and dune erosion during extreme storm events. These observations are used to evaluate and develop computer models for predicting water levels at the shoreline driven by surge and waves, which are used by the USGS to identify the vulnerability of our coasts to flooding and erosion during storm events.

Most recent time-averaged from Madeira Beach, Florida. The images are used to examine a range of coastal processes including shoreline position, the presence of an offshore sandbar, and the extent of wave runup on the beach. (Operated by: Camera hosted by Shoreline Island Resort.)

Most recent time-averaged from Sand Key, Florida. The images are used to examine a range of coastal processes including shoreline position, the presence of an offshore sandbar, and the extent of wave runup on the beach. (Operated by: Camera hosted by Dan's Island Condo.)

How does it work?

Remote video cameras are a powerful tool to continuously monitor long stretches of coast. The system is non-intrusive, runs automatically, requires little maintenance, and consists of:

  • a video camera housed in a weather-proof case mounted atop a tall beachfront structure with an unobstructed seaward view, and
  • a mini-computer wired to the camera and stored in a sheltered location with power and internet access.

At regular intervals, during daylight hours, the camera collects snapshots and videos. Each square element in an image, called a pixel, contains color intensity information, which can be used to extract information about the changing coastline.

How is it used?

The use of video cameras to monitor ever-changing coastal conditions eliminates the need to deploy individual instruments, which can be time consuming and do not provide observations at all times and at all locations. Images and videos taken from cameras are useful for observing current coastal conditions and for comparing how conditions along the coast change through time. This includes, for example, tracking increasing water levels during a storm and monitoring the potential impacts of waves colliding with protective sand dunes.

changing beach conditions throughout the day

Snapshots, like these taken (a) before and (b) during a winter storm at the U.S. Army Corps of Engineers Field Research Facility in the Outer Banks, North Carolina, show changing beach conditions throughout the day. During this storm, high waves and surge created shoreline water levels that reached the steps of a beach access, indicated by the arrow. (Public domain.)

A video, or sequence of individual images, can also be processed to create various image products, which can be used to actually measure a range of coastal processes, including:

  • wave runup
  • regular and extreme water level statistics
  • shoreline position
  • sandbar existence and movement
  • rip current presence
  • coastal change

For example, time-averaged images, which represent the time-mean of all the images collected during a video, are used to identify areas where waves are breaking, which show up as bright white bands in the image. From this image product, coastal features and hazards such as the shoreline position as it moves up and down the beach with the tide, the presence and shape of offshore sandbars, and the occurrence of rip currents can be extracted. Changes in all of these features through time provide valuable insight into the dynamic nature of coastal environments.

Bright white areas in time-averaged images show the presence of wave breaking

Bright white areas in time-averaged images show the presence of wave breaking. These images from the U.S. Army Corps of Engineers Field Research Facility in the Outer Banks, North Carolina, reveal the presence of (a) rip currents and (b) beach cusps, and expose (c) straight and (d) complex offshore sandbars. (Public domain.)