উন্নত করার কিছু দেখছেন? একটি পরিবর্তন প্রস্তাব করুন।
Status of 3D Elevation Program baseline lidar data in Arkansas, May 2023: available or in progress statewide. USGS figure.
Why elevation data matters
Arkansas has worked with federal and local partners to improve the quality and availability of high-resolution elevation data — improving public services, public safety and returns on investment. The key is lidar (light detection and ranging), which builds a detailed three-dimensional model of the land surface and everything on it.
The 3D Elevation Program (3DEP), run by the U.S. Geological Survey with federal, state, Tribal, territorial and local partners, is collecting consistent lidar nationwide at quality level 2 or better. Its baseline products — 1-meter or better digital elevation models and lidar point clouds — must meet the Lidar Base Specification version 1.2 or newer.
| Quality level | Vertical error (RMSEz) | Pulse spacing | Pulse density |
|---|---|---|---|
| QL0 (highest) | ≤5 cm | ≤0.35 m | ≥8.0 per m² |
| QL1 | ≤10 cm | ≤0.35 m | ≥8.0 per m² |
| QL2 | ≤10 cm | ≤0.71 m | ≥2.0 per m² |
What it's worth to Arkansas
A National Enhanced Elevation Assessment (Dewberry, 2012) conservatively estimated that lidar would bring Arkansas at least $7.32 million a year in new benefits. Quality level 2 coverage is 100 percent complete.
| Rank | Business use | Annual benefits (millions) |
|---|---|---|
| 1 | Agriculture and precision farming | $2.39 |
| 2 | Natural resources conservation | 2.12 |
| 3 | Flood risk management | 1.47 |
| 4 | Infrastructure and construction management | 0.59 |
| 5 | Forest resources management | 0.30 |
| 6 | River and stream resource management | 0.15 |
| 7 | Geologic resource assessment and hazard mitigation | 0.11 |
| Other | 0.19 | |
| Total | 7.32 |
How it's used
Flood risk management. In spring 2019, record-breaking floods swamped homes, businesses, farms and whole communities — some with no history of flooding — destroying crops and halting river traffic. Lidar improves inundation and forecast models, helps analyze the timing and impact of floods, and plans evacuation routes. In 2017, the Federal Emergency Management Agency and the Department of Agriculture's Natural Resources Conservation Service led collection of quality level 2 lidar over large parts of the state, including flooded areas.
Lidar-derived 5-foot contours (white lines) were a critical tool for emergency managers during the Arkansas River's historic flooding in spring 2019. USGS figure.
Natural resources conservation. Lidar helps governments with grade stabilization, dam safety, habitat easements, pipeline siting, terracing, wetland restoration and protecting sensitive areas, while saving money. Quality level 2 lidar is being used for detailed geologic mapping of a watershed in northwestern Arkansas, used by the conservation service.
Urban and regional planning. Planning commissions and local governments use elevation data for sustainable development — transportation, land use, cultural assets, public safety, water supply and infrastructure. Regional data cuts the time spent gathering base data, and maps of current and future conditions help inform the public and elected officials.
Geology and hazards. The Arkansas Geological Survey, with USGS grants, uses elevation data for detailed mapping, study of geologic structures, and assessment of critical minerals, supporting a mineral and fossil-fuel industry worth more than $1 billion a year. It is also compiling a statewide landslide inventory from 1-meter lidar, since geologic hazards damage property, disrupt utilities and cut off access.
About 3DEP
- Goal: complete nationwide lidar (radar in Alaska) for the first national baseline of consistent, high-resolution elevation data.
- Quality: at least two points per square meter and vertical error of no more than 10 centimeters.
- Benefits: economies of scale, predictable federal investment, consistent coverage across boundaries and simpler acquisition — conservatively $690 million a year nationally, with potential for $13 billion more.
- Free data: products are in The National Map, free and unrestricted — download them here.
- Partnering: governments and the private sector can fund projects, receive cooperative funds, or contribute qualifying data, through an annual Broad Agency Announcement — see 3DEP collaboration.
Sources
Based on Chris Cretini, "The 3D Elevation Program—Supporting Arkansas's economy," U.S. Geological Survey Fact Sheet 2023–3018, U.S. Geological Survey; a work of the United States government in the public domain. Its figures and tables, which the import did not carry, are taken from the fact sheet PDF.
লাইসেন্স: CC0 1.0 (পাবলিক ডোমেইন) · গৃহীত হয়েছে pubs.usgs.gov
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