Description: Breaklines of ponds and shoreline from the LiDAR 2021 survey. The dataset includes the breaklines of Martha's Vineyard Island and Nomans Island. A breakline indicates where the LiDAR data indicated zero elevation (NAVD88 vertical datum). The breaklines are not tidally corrected. Hence, one can not say with certainty if a breakline represents MHW mean high water or some tidal variation thereof. The Martha's Vineyard Commission assigned an attribute to the breaklines to indicate if it was ocean coastline or a pond shoreline.
Copyright Text: Original LiDAR data & breaklines - NV5 2021; Martha's Vineyard Commission - 2025 minor attribute edits.
Description: Breaklines of ponds and shoreline from the LiDAR 2021 survey. The dataset includes the breaklines of Martha's Vineyard Island and Nomans Island. A breakline indicates where the LiDAR data indicated zero elevation (NAVD88 vertical datum). The breaklines are not tidally corrected. Hence, one can not say with certainty if a breakline represents MHW mean high water or some tidal variation thereof. The Martha's Vineyard Commission assigned an attribute to the breaklines to indicate if it was ocean coastline or a pond shoreline. From that dataset, the coastline of Martha's Vineyard was buffered 1 nautical mile. The buffer was split by the coastal breakline to distinguish the area intersecting the ocean vs that intersecting landward. All buffers were merged into this dataset. All data were processed in ArcPro.
Copyright Text: Original LiDAR data & breaklines - NV5 2021; Martha's Vineyard Commission - Buffer 2026