VBMP Digital Terrain Models - 2006/2007 (VA State Plane South)

Terrain data, as defined in FEMA Guidelines and Specifications, Appendix M: Data Capture Standards, describes the digital topographic data that were used to create the elevation data representing the terrain environment of a watershed and/or floodplain. Terrain data requirements allow for flexibility in the types of information provided as sources used to produce final terrain deliverables. Once this type of data is provided, FEMA will be able to account for the origins of the flood study elevation data. These files contain Digital Elevation Model (DTM) file data for the State of Virginia developed from imagery acquired in spring 2006 and 2007. In the spring of 2006, the Commonwealth of Virginia, through the Virginia Geographic Information Network Division (herein referred to as VGIN) of the Virginia Information Technologies Agency (VITA) contracted with the Sanborn Map Company to provide Aerial data acquisition, ground control, aerotriangulation and development of statewide DTM and digital orthophotography. The project encompasses the entire land area of the Commonwealth of Virginia. The State boundary is buffered by 1000'. Coastal areas of the State bordering the Atlantic Ocean or the Chesapeake Bay shall be buffered by 1000' or the extent of man-made features extending from shore. The entire State was intially designed to support 1"=200' (1:2400) scale mapping. Jurisdictions throughout the State were provided an option to upgrade to a 1"=100' (1:1200) map scale. All data development processes for the DTM conform to the ASPRS Draft Aerial Photography Standards (1995) and Model Virginia Map Accuracy Standards (1992), which generally follow the ASPRS Accuracy Standard for Large-Scale Mapping (1990) for relevant mapping scales. The DTM supports the creation of 6-inch or 1-foot map orthoimagery at the relevant scales.