How Lidar Elevation Data Supports Maine's Economy

Inland flooding, sea-level rise and pollution all strain Maine's infrastructure and natural resources. A highly detailed three-dimensional model of the land surface — built from lidar (light detection and ranging) data — is helping the state tackle them faster and more thoroughly. Accurate elevation data also supports land development, forestry, farming and wildlife conservation, all key parts of Maine's economy. In its annual report for 2018, the Maine Library of Geographic Information said elevation data were transforming land development costs for the private and public sectors of the state's economy.

The 3D Elevation Program

The U.S. Geological Survey manages the 3D Elevation Program (3DEP) with federal, state, Tribal, territorial and local partners. Its goal is the first national baseline of consistent, high-resolution elevation data — lidar across the country, and radar (IfSAR) in Alaska — covering both bare-earth elevation models and 3D point clouds.

3DEP baseline data must be quality level 2 or better:

Products include every point collected (point clouds) and bare-earth digital elevation models at 1-meter resolution or better, meeting the Lidar Base Specification version 1.2 or newer. The data go into The National Map and are free, with no restrictions on use.

Status of 3DEP baseline lidar data in Maine as of August 2022. USGS figure.

3DEP in Maine: quality level 2 coverage is 100 percent complete (levels 0 and 1 cost extra), and the National Enhanced Elevation Assessment conservatively estimated at least $4.7 million a year in new benefits for the state.

Where the benefits come from

The assessment's top business uses for Maine:

Flood risk

The Maine Floodplain Management Program works with residents, communities and floodplain professionals to steer development away from flood zones. More than 9,000 flood insurance policies are in force in the state, covering over $1.9 billion in property judged to be at risk. Accurate lidar could improve community flood maps, give a better picture of which properties are at risk, and possibly lower insurance rates.

A flood-depth map laid over a digital elevation model — the kind of product that can support new community flood-zone maps. Graphic by Luke Sturtevant, USGS.

Water supply

Forty-eight percent of the water the public uses in Maine comes from surface-water utilities. Lidar lets the organizations responsible for water quantity and quality draw watershed boundaries more precisely — which is needed to estimate stormwater runoff in small urban watersheds and to track and manage pollution sources.

Coasts and lobstering

Maine's fishing industry relies on long-term management of the coast, which needs intertidal elevations, sea-floor depths and upland terrain stitched seamlessly together. In 2017 the lobster industry's supply chain contributed $1 billion to the state economy, and landed lobsters were worth $433 million. Lidar can improve coastal hazard models, identify and analyze impervious surfaces, and inform resilience and storm-response plans.

Forests

The forest products industry benefits directly from public lidar. A 2016 Maine Forest Products Council report estimated the industry's yearly statewide impact at $8.5 billion in sales output and $1.8 billion in labor income, supporting 33,538 full- or part-time positions. Foresters use lidar point clouds to calculate biomass, tell tree types apart, and map terrain suited to wildlife habitat such as deer wintering areas; accurate elevation models also help detect changes in vegetation and map wet areas.

National benefits and how to take part

Nationally, 3DEP's benefits are conservatively put at $690 million a year, with the potential for $13 billion a year more across the economy. Buying data for large areas brings economies of scale, predictable federal funding allows better planning, and consistent coverage serves work that crosses project, jurisdiction and watershed lines.

Federal, state, Tribal, territorial and local governments and private companies can join. Partners can fund USGS-managed projects, receive cooperative funds to run their own, or contribute existing data that meet 3DEP requirements; agreements are set up through an annual Broad Agency Announcement.

Sources

• U.S. Geological Survey: "The 3D Elevation Program—Supporting Maine's economy," Fact Sheet 2023–3036.
• Works cited by the fact sheet include the National Enhanced Elevation Assessment (Dewberry, 2012); the Maine Library of Geographic Information's FY 2018 annual report; the Maine Floodplain Management Program; the Maine Division of Environmental and Community Health; the Island Institute (2018); and Crandall and Anderson (2016), University of Maine.