As part of the Assateague Island National Seashore (ASIS) North End Restoration Project, sediment is being dredged from the Ocean City tidal delta complex, and deposited in the near shore of Assateague Island. The dredging is performed by the US Army Corps of Engineers (USACE) dredge boat Currituck, which is a split-hull hopper dredge. GPS point locations are recorded when the hull opens and deposits sediment (labeled as 'Placement' in the 'Event' attribute) and also when sediment samples are collected during borrow events (labeled as 'Dredge Sample' in the 'Event' attribute.) As a result, this data set provides the locations of dredge events that were conducted aboard the USACE vessel Currituck from January of 2004 thru March of 2004, around the Ocean City, MD Inlet, Assateague Island, and Ocean City, MD.
These data are collected, stored, and managed as per the guidance in the ASIS North End Restoration Plan. The purpose of this dataset is to be able to monitor the locations of dredging events off the coast of Assateague Island National Seashore and Ocean City Maryland throughout the North End Restoration Project.
There are usually two dredge events a year, starting in 2004, during the spring and fall seasons. The file name of each dataset corresponds to the year and month dredging began. There are a variety of other North End Restoration Project data these data can be used with including bathymetry surveys before and after each dredge event, planned dredge locations, and shoreline and profile monitoring data on Assateague Island.
ground condition
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Topology was created for this data set.
This data set contains all sample and placement coordinates provided to ASIS, from the USACE Currituck dredging vessel. This data pertains to dredge events that took place from 20050918 to 20051113 off the coast of Assateague Island National Seashore and Ocean City Maryland. The points were collected using a GPS onboard the United States Army Corps of Engineers dredging vessel Currituck. The accuracy of these points is not known, and there may be other dredge events that were not collected by GPS, or provided to ASIS.
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As the USACE Currituck dredging vessel is undergoing a dredging operation, the crew and equipment collect GPS points during two specific events. One event is when the split-hull of the Currituck opens, and deposits sediment. The other is during a borrow event, as the vessel is collecting sediment, and a sediment sample is taken for future analysis.
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These coordinates are then provided to ASIS, in either hard copy or digital format. The coordinates are converted into a geographic latitude and longitude projection, and UTM NAD83, Zone 18, meters projection. These newly converted coordinates are put into the same table, along with other information provided by the USACE, such as dates, event types, point names and comments. This table is then imported into ArcGIS, and saved as an ESRI shapefile. Metadata is documented after the shapefile is finalized.
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Dataset copied.
Internal feature number.
ESRI
Feature geometry.
ESRI
Used to determine exact feature location
ASIS
This field determines what type of dredge event occured
ASIS
Denotes a placement event, meaning this point portrays a location where the Currituck's split hull opened and deposited sediment.
ASIS
Denotes a borrow event, this point portrays a location where the Currituck was filling with sediment, and a sample was collected for future analysis.
ASIS
Dredge event descriptions were not provided to ASIS, so it is unknown whether this point portrays a placement or borrow event.
ASIS
Coordinates used to identify exact feature location
ASIS
Date of dredge event
ASIS
Coordinates used to identify exact feature location
ASIS
Used to distinguish points, and dredge events
ASIS
Used to determine exact feature location
ASIS
Used in original hardcopy format
ASIS
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