Lidar Elevation Data for Ohio: The 3D Elevation Program

Publicly available lidar in Ohio, October 2014, from the U.S. Interagency Elevation Inventory (updated yearly). None of it meets 3DEP's requirement of quality level 2 or better. USGS.

Why elevation data matters

Elevation data serve forestry, wildlife and habitat management, national security, recreation and much else. In Ohio they matter most for agriculture and precision farming, natural resources conservation, flood risk management, infrastructure and construction, and water supply and quality. High-density lidar is now the main source of elevation models. Federal, state, tribal and local agencies work together to replace older, lower-quality data and fill gaps, aiming for consistent statewide coverage.

By the numbers

About 88% of the identified needs fall in agriculture, conservation and flood risk management. Not every benefit had a dollar value, so the true total is likely much higher.

How lidar helps Ohio

A statewide platform. The Ohio Geographically Referenced Information Program already gives access to digital geographic data across the state and is well placed to support 3DEP. Ohio's key users have recently stressed lidar for solar potential mapping — siting photovoltaic panels — as well as siting oil and gas wellhead pads for horizontal drilling, modelling impervious surfaces, archaeological surveys, shoreline erosion, road slope and curve analysis for traffic safety, and economic development. Many Ohio Department of Natural Resources (ODNR) programs use it, among them the Office of Coastal Management for shoreline recession and coastal erosion mapping.

Hidden hazards. The ODNR's Ohio Geological Survey uses lidar to map karst, and the Division of Mineral Resources' Abandoned Mine Land Reclamation programmes use it to find subsidence and possible sinkholes. Thick vegetation and woodland can hide dangerous ground; bare-earth lidar models reveal abandoned mine lands, active landslides, old landslides that could move again, and sinkholes too small or too new for earlier elevation data to show. These models support public and environmental safety and help industry and business choose sites.

About 3DEP

The National Enhanced Elevation Assessment (Dewberry, 2011) found the best return from quality level 2 lidar for the conterminous United States and quality level 5 radar (ifsar) for Alaska, refreshed every 6 to 10 years; 3DEP chose an 8-year cycle. The USGS — the federal lead agency for land elevation data — runs it, and its data improve on the older National Elevation Dataset.

• Goal: complete national coverage by the end of 2022, depending on funding and partners; lidar at quality level 2 or better over the conterminous states, Hawaii and the territories, ifsar in Alaska, all made public.
• Value: conservatively $1.2 billion a year nationally, with the potential for $13 billion a year — from better government services, smaller crop and flood losses, more efficient vehicle routing and more.
• Why a national program: larger purchases cut costs by 25%; buying high quality once avoids paying to "buy up" later; consistent data across state and watershed lines; more federal money reduces state and local shares; and ready contracts and specifications simplify buying.
• What it depends on: more partnerships among federal, state, tribal and local governments; partners buying to the program's specifications over larger areas; wider awareness of its benefits; and support from government and other stakeholders.

Sources

Based on William J. Carswell, Jr., "The 3D Elevation Program—Summary for Ohio," U.S. Geological Survey Fact Sheet 2014–3111, version 1.1 (June 2015); a work of the United States government in the public domain. The map and tables are taken from the fact sheet's PDF; its solar-mapping illustration, credited to the Ohio Department of Natural Resources, is left out. Benefit figures come from Dewberry's National Enhanced Elevation Assessment (2011, revised 2012).