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Beach Morphology Monitoring Program
Monitoring Program Design
The coastal management community uses scientific data in at least three ways: informing long-range planning, permitting and reviewing shoreline stabilization projects, and guiding coastal management practices, e.g., zoning, setbacks, development standards, etc. The ideal beach monitoring program would provide information to support each of these functions. Therefore, monitoring efforts need to be explicitly directed towards understanding coastal change at scales relevant to the management community (decades and tens of kilometers).
Coastal change occurs temporally from seconds (e.g., individual waves) to decades (e.g., climate variability such as the Pacific Decadal Oscillation) and spatially from centimeters (e.g., ripples) to hundreds of kilometers (e.g., littoral cells). The figure below illustrates the the temporal and spatial components of beach change. The plot is vertically exaggerated to show elevation change between the lower shoreface and the dunes.
The evolution of the sub-aerial beach is often of principal interest in coastal management due to its proximity to valuable upland properties and community infrastructure. The sub-aerial beach is also one of the most dynamic places within the active coastal zone where tens of meters of shoreline recession can occur in just a few hours as a result of a major storm. This portion of the active coastal zone is readily available for measurement, and as a result, most beach monitoring programs focus on measuring the temporal variability of the visible beach. The Study monitors this portion of the coastal zone by collecting beach profiles, topographic surface maps, scarp walks, and sediment samples.
The sub-aerial beach, however, comprises only a small percentage of the active coastal zone. In order to develop reliable predictive capabilities of shoreline change, an understanding of the sub-aqueous beach variability is also necessary. Since offshore sandbars dissipate wave energy and provide a buffering capacity that protects the sub-aerial beach, the position and height of sandbars, as well as, the overall beach slope may affect the susceptibility of the shoreline to the erosive power of waves. This portion of the active coastal zone is much more difficult and expensive to measure and only a relatively few long-term data sets exist worldwide. The Study monitors changes to nearshore bathymetry with the Coastal Profiling System.
Follow these links for more information on how the monitoring program employs GPS equipment or to view a map of the monitoring program sampling locations. Or, select a topic from the list at the top of this page for a description of survey techniques.
