DEVELOPMENT OF HIGH-RESOLUTION, LIDAR-DERIVED DIGITAL ELEVATION MODELS FOR THE U.S. GREAT LAKES

The NOAA National Geophysical Data Center has recently developed high-resolution, integrated bathymetric-topographic digital elevation models (DEMs) of the U.S. shoreline of the Great Lakes. The DEMs were built at a 1/9 arc-second resolution (~3 meter cell size), and will support an interactive map viewer being developed by the NOAA Coastal Services Center that visually illustrates positive and negative changes in lake water levels relative to lake low water datums. The DEMs extend inland 1.5 km from the shoreline (or to roughly the 5-meter contour) and only include areas where publicly available topographic and/or bathymetric lidar exist. As such, the DEMs also serve to indicate where additional lidar data collection is required. Significant technical challenges, such as selective limitation of interpolation and co-registration with existing gridded datasets, will be discussed in the context of overall DEM development methodology. The EPA Great Lakes Restoration Initiative has funded NOAA to collect new topographic and bathymetric lidar, build the DEMs, and visually portray the extents of potential lake-level change in the interactive map viewer.