Lidar Elevation Data for Indiana: The 3D Elevation Program

Publicly available lidar in Indiana, 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 Indiana they matter most for flood risk management, agriculture and precision farming, natural resources conservation, infrastructure and construction, and aviation safety. 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 83% of the identified needs fall in flood risk management and agriculture. Not every benefit had a dollar value, so the true total is likely much higher — and closer coordination between 3DEP and Indiana's public and private organisations could reach beyond these conservative figures.

How lidar helps Indiana

Floods. Lidar gives better, cheaper terrain for hydrologic and hydraulic flood studies; for designing bridges and culverts to carry runoff from big storms; and for retention-dam design, dam-breach studies and stormwater engineering. It helps find vulnerable properties in floodplains, supporting better floodplain decisions and showing the public its real flood risk. Dynamic 3D models add detail on what a flood could do, and more accurate flood-inundation maps mean better regional and site-level forecasts and responses — lowering costs and saving lives.

Geology. Lidar can locate geologic features more precisely and reduce the need to take survey-grade equipment into the field. Better geologic maps support assessments of natural and industrial resources, geologic framework models, aquifer sensitivity, mine reclamation studies, seismic and karst hazard analyses and public safety — and better surficial-geology products help protect groundwater and wetlands.

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 Indiana," U.S. Geological Survey Fact Sheet 2014–3113, 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 photograph of Eel River flooding, credited to Indiana Public Media, is left out. Benefit figures come from Dewberry's National Enhanced Elevation Assessment (2011, revised 2012).