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In eastern Arkansas, crops depend on irrigation, and the groundwater of the Mississippi River alluvial aquifer is being drawn down faster than it can be replenished. To ease the demand, farmers have built hundreds of on-farm reservoirs to catch rainwater and runoff for the dry season. But exactly how many there are, and what they do to the surrounding environment, has not been clear. Landsat satellite data are helping to find out.
Rice fields in eastern Arkansas, with on-farm reservoirs in the background. Credit: Lance Cheung, U.S. Department of Agriculture.
Arkansas lives up to its nickname, "The Natural State": the Ozark Plateau and the Ouachita Mountains offer views, resources and recreation, hardwood and pine forests cover half the state, and the Arkansas, Ouachita, Red and White Rivers carry recreation and navigation.
Three uses in Arkansas
| Question | What Landsat showed |
|---|---|
| How many farm reservoirs are there? | University of Arkansas researchers ran 20 years of Landsat data through the USGS Dynamic Surface Water Extent (DSWE) algorithm to map the growing number and locations of reservoirs in Arkansas County (West and Kovacs, 2018). U.S. Department of Agriculture and university researchers used DSWE and another Landsat-based dataset to follow reservoir changes across eastern Arkansas over 23 years, including seasonal patterns and swings in temperature and rainfall (Perin and others, 2021). |
| What is planted where? | Arkansas was one of the few states in the USDA's first Cropland Data Layer in 1997. Built on Landsat and other data, the layer now reports crop type, acreage and yield for every state each year — what is planted, how much, where, and where land use has changed — helping growers and others in agriculture make sound land decisions. |
| How fast is the northwest growing? | Northwestern Arkansas, home to the University of Arkansas and the headquarters of several large national and international companies, has grown notably since the mid-1990s. University of Arkansas researchers used Landsat to map that growth from 1995 to 2015, when and where it happened (Reynolds and others, 2017), helping city officials understand development and its effects on residents and the environment. |
Central Arkansas: forest (darker green) and pasture (lighter green) in the western two-thirds, and in the east a mix of rice (bright blue), corn (gold), cotton (red) and soybeans (dark green). Gray is developed land, dark blue water, gray-blue wetlands. Credit: U.S. Department of Agriculture, 2021.
Urban growth (gray) around Bentonville, Springdale and Fayetteville in Landsat scenes from 1995 and 2015. Credit: U.S. Geological Survey.
About Landsat
- Who uses it. Landsat is the most widely used land remote-sensing data source in federal civilian agencies, and local, state and Tribal agencies use it too, to monitor and forecast changes on the land surface. Businesses use it to improve logistics, resource allocation and investment decisions; commercial imaging firms use it to refine their products.
- What it is worth. A 2017 USGS study put the annual economic benefit of Landsat data in the United States at $2.06 billion, far more than it costs to build and run (Straub and others, 2019).
- How often. Landsat 8 and Landsat 9 together cover Earth's land every 8 days.
- How long. Landsat is the world's longest record of Earth's land surface, now 50 years long. NASA and the USGS are planning its successor, Landsat Next.
- What it costs users. Nothing: the data are free, which, with their consistency and accuracy, lets users study large areas and long-term change. Worldwide access comes through the USGS Earth Resources Observation and Science (EROS) Center, funded by the National Land Imaging Program.
Sources
Based on "Arkansas and Landsat," U.S. Geological Survey Fact Sheet 2022–3042, a work of the United States government in the public domain.
Licencia: CC0 1.0 (dominio público) · Adaptado de pubs.usgs.gov
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