Army Corps of Engineers (USACE), Bureau of Ocean Energy Management (BOEM), and State resource agencies are faced with the management of diverse marine resources to sustain the ability to continue to address community vulnerability in the face of major disasters. east coast, recent extreme weather, like Hurricane Katrina and “Superstorm” Sandy”, brought such concerns to the forefront. In this way, areas of disturbed benthic habitat can be identified, even if changes in bathymetry are not resolved.Ĭoastal communities increasingly are challenged by the need to exploit the offshore sand resources in order to recover from beach erosion brought on by severe storms. If vessel displacements is also monitored, increases in displacement will also identify times and locations of active extraction. Because sand dredging using a trialing hopper dredge is done at slow speeds, the aggregate time that a dredger spends in each cell can be modified by dredger speed to discriminate time spent actually removing sand from time spent in transit.

The aggregate count of positions in each cell can be displayed in a graphic image called a “heat map” (or “density map” or “timeprint”) where various intensities of colors represents the number vessel locations in each designated cell over the entire time period of interest as a surrogate for dredging intensity. The designated borrow area is divided into grid cells, in this example, 100 × 100 m. The GIS model to do this requires monitoring of the dredger location (including speed and displacement, if available). The sustainability of offshore sand reserves and the impact of their exploitation for coastal resilience can be assessed by resource managers via GIS.

Coastal dredging data