Milestone of Statewide High Resolution Elevation Data has been reached

Concord, NH – The New Hampshire Geological Survey (NHGS) at the New Hampshire Department of Environmental Services (NHDES) announced today that statewide coverage (= 9,350 square miles) high resolution elevation data (LiDAR) for all of New Hampshire is complete. The project, which began nine years ago, includes data from the last of eight individual acquisition projects are now publicly available and complete the statewide LiDAR mosaic. A host of funding partners have contributed to this effort, including the State of New Hampshire, U.S. Geological Survey, Federal Emergency Management Agency, and the Natural Resources Conservation Service and the Forest Service within the U.S. Department of Agriculture.

LiDAR is shorthand for Light Detection and Ranging, an airborne laser scanning technology for mapping the earth’s surface in unprecedented detail, even beneath the forest. LiDAR bounces pulses of laser light off the ground and measures the down-and-back travel time to determine a highly accurate elevation for each reflected pulse, tens of thousands of times each second, while a pilot holds a steady course.

The landscape that emerges from the processed LiDAR data reveals amazing detail of landforms large and small, sometimes so subtle that you could walk right over or past them and never realize they were there. Vertical accuracies of the resulting elevations are reported in inches rather than feet, far superior to the elevation contours on the series of existing U.S. Geological survey topographic quadrangle maps. Probably the most important use of the LiDAR data is the topographic base for updating flood hazards maps. Public safety officials also value the increase in accuracy that is possible when predicting the impacts of sea level rise on coastal communities. There are potential benefits in forest management and soils and wetlands mapping as well.

Rick Chormann, State Geologist and Director of the NHGS, reports that LiDAR has completely revolutionized geologic mapping in the state: “So much of our modern New Hampshire landscape is concealed by tree cover that finding bedrock outcrops and identifying glacial landforms in the field is a significant challenge. But the bare-earth LiDAR landscape reveals almost unimaginable details that we never otherwise be able to see and map.”

To download the LiDAR data as archived in NH GRANIT, please visit http://lidar.unh.edu/map/. In addition, and in order to invite the public to take a closer look, NHGS worked to develop the NH Stone Wall Mapper with funding support from the NH Charitable Foundation and technical assistance from UNH GRANIT. You can explore all of the resources associated with this project at www.granit.unh.edu/resourcelibrary/specialtopics/stonewalls/ .

For more information, please contact Rick Chormann, State Geologist and Director, NH Geological Survey at frederick.chormann@des.nh.gov or (603) 271-1975.