in at ≤ ' Elevation (NAVD88)
Update: This visualization has been updated on 6/11/2016 to correct an error in the original elevation mapping. See text below for details on methods.
Methodology: 1' - 9' topography lines were generated using QGIS and the 1 arc-second DEM from the National Elevation Dataset (NAVD88). These topography lines were used as the basis to select census blocks and city features. Analysis includes all census blocks that fall fully or partially below the elevation thresholds based on the National Elevation Dataset.
Caveats: This visualization only identifies features below user-selected elevation thresholds, referenced to the NAVD88 vertical datum. It does not employ a hydrological model. While elevation broadly correlates with inundation risk, these maps should not be interpreted as being one-to-one equivalent to sea level rise impacts, as they do not account for tides, local urban features such as canals or stormwater infrastructure, or elevation differences between NAVD88 and current mean sea level. Storm events are also not factored in. For example, for a rise in sea level of 5', features shown here at elevations greater than 5' could potentially be inundated during high tides or storm events. A more detailed analysis of the NYC area is required to determine actual vulnerability to flooding.
Visualization and analysis by B. Wellington and M. Seibert of Landscape Metrics, LLC