Coastal Change Assessment

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Regional coastal sediment transport processes influence the evolution of sedimentary environments to varying degrees depending on temporal and spatial response scales. A primary focus for Applied Coastal personnel is quantification of historical trends in shoreline position, bathymetry, and wetland elevation at varying spatial and temporal scales. This has been accomplished by developing innovative strategies that take advantage of state-of-technology advances in surveying, computer mapping, and GIS. Topographic and hydrographic surveys of coastal and nearshore environments provide a direct source of data for quantifying system response. Applied Coastal uses these data (historical maps, photogrammetric surveys, geodetic GPS surveys, lidar surveys) to evaluate coastal change trends at various sites along the U.S. coast (Louisiana, Mississippi, Alabama, Florida, New York, Massachusetts) in relation to normal incident coastal processes, storm impacts, relative sea-level change, and human modifications of the coast.

Shoreline changes document subaerial dynamics of the land-water boundary in response to dominant coastal processes. To understand three-dimensional influences on shoreline dynamics, hydrographic surveys of regional nearshore morphology provide a direct source of information for quantifying changes in seafloor elevation. Furthermore, lidar data provide subaerial elevations that create a relatively seamless transition with seafloor elevations for developing coastal and nearshore morphology surfaces. Comparison of digital elevation data for the same region but different time periods records net movements of sediment into (accretion) and out of (erosion) an area of study (sediment budget). Applied Coastal personnel use these data to quantify regional and local changes to identify trends in coastal/shelf sediment dynamics, and to evaluate the impact of natural processes and human influences on a project area. Applied Coastal personnel have conducted these kinds of studies along all U.S. coasts to evaluate long- and short-term changes in coastal response to physical processes, particularly as they relate to tidal-influenced sedimentation patterns associated with inlets and adjacent coastal reaches.

 Capabilities

  • Shoreline change
  • Nearshore bathymetry change
  • Inlet shoal dynamics
  • Regional sediment transport dynamics
  • Sediment budget analysis
  • Coastal structure impact analysis
  • Wetland change detection
  • Wetland subsidence and consolidation settlement
  • Coastal geologic assessments
  • Sea-level change analyses

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