In the early 2000s, due to the remote and uninhabited vastness of the state of Alaska, traditional survey and mapping methods were not applicable for feature extraction. Between 2010 and 2020, Dewberry mapped the state of Alaska, with quality level 5 (QL5) interferometric synthetic aperture radar (IFSAR) data, including hydro-enforced digital terrain models (DTM) with cell-size resolution of five meters. Dewberry used this IFSAR data and applied a semi-automated approach to create new hydrographic flowlines and connectors meeting specifications of the 1:24,000 scale NHD. The updated network will result in approximately three times the number of NHD features as before.

“The collaborative efforts of USGS, local stakeholders, and private companies such as Dewberry are paramount to making a project like this succeed,” says Dewberry Associate Vice President, Mark Safran. “The updated hydrographic features of the NHD will be a benefit to all inhabitants as well as preserving the wilderness that Alaska, is known for, for generations to come.”

USGS is spearheading the collaboration of federal, state, and private industry officials to leverage the GPSC contract vehicle for updating NHD. Dewberry is supporting this effort to improve the geographic data for those that live, work, preserve, and protect the state of Alaska.