New Landscape Data Can Help New Hampshire Plan for Floods

Laser-equipped aircraft have been scanning the New Hampshire landscape, creating high-resolution topographical maps that could help the state with everything from emergency preparedness to the expansion of wireless broadband.

So far, data covering 900 square miles of eastern New Hampshire has been gathered by planes carrying lasers that emit thousands of pulses of red light per second to calculate the distance from the aircraft to the ground.

The resulting maps show the elevation and shape of the landscape as if stripped of all trees and buildings, and are part of a larger project encompassing 9,000 square miles from New York to Maine. The bigger project involves multi-agencies in various states and is funded by federal stimulus money through the U.S. Geological Survey.

The first phase focused on the East Coast, with the goal to eventually expand inland, said Fay Rubin, director of the Earth Systems Research Center at the University of New Hampshire.

Rubin, who directs a cooperative project between UNH and the state to create and maintain a statewide geographic database, said UNH researchers are using the New Hampshire data to produce updated flood plain maps for coastal communities. Previous maps were based on data from the 1980s and were at much lower resolution than the new data, she said.

“It’s a tremendous increase in the accuracy and currency of the data, which will allow us to be much more accurate” in identifying areas most susceptible to flooding, she said.

The state Department of Environmental Services will use the data to evaluate the potential for stream bank erosion, she said. The data also could be used by Network New Hampshire Now, a public-private collaboration led by the state university system to expand broadband Internet access in all 10 counties and to create a wireless public safety network.

“his data would help us understand where signals can and can’t travel,” she said.

Previous topo map technology was based on aerial photography, which can be accurate but is painstaking and time-consuming, Rubin said.

“Even in a digital environment … it’s not feasible to do over a large geography in a cost-effective way,” she said.