Name: SAV 2021

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Description: The 2021 Chesapeake Bay SAV Coverage was mapped from digital multispectral imagery with a 25cm GSD to assess water quality in the Bay. WorldView 2 from Maxar and PlanetScope satellite imagery from Planet Labs were used to augment the aerial imagery for the Anacostia River and the upper Potomac River, and middle Rappahannock River, including Menokin Bay and Cat Point Creek, the Mattaponi, Pamunkey, and the majority of the Chickahominy and James rivers, and Mobjack Bay. NAIP aerial imagery was used to augment the aerial imagery for the Chester, Choptank, Little Choptank, Magothy, and Miles rivers, Harris Creek, Eastern Bay, the western shore of Chesapeake Bay along the Calvert Cliffs, the Great Wicomico River and western shore of Chesapeake Bay from the mouth of the Rappahannock River up to Ingram Bay.. Each area of SAV was interpreted from the rectified imagry and classified into one of four density classes by the percentage of cover. The SAV beds were entered into an SDE GIS fetaure class using the quality control procedures documented below. The dataset contains all SAV areas that were identified from the areas flown. Some areas that are presumed to contain no SAV were not flown. Some small beds, particularly along narrow tributaries may not have been distinguishable on the aerial photography.

Copyright Text: SAV Monitoring Program, Virginia Institute of Marine Science

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Fields:

• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
• QUADID ( type: esriFieldTypeInteger, alias: QUADID )
• BEDID ( type: esriFieldTypeString, alias: BEDID, length: 2 )
• DENSITY ( type: esriFieldTypeInteger, alias: DENSITY )
• BEDLABEL ( type: esriFieldTypeString, alias: BEDLABEL, length: 6 )
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