Earth  ID: 10973

Crop Circles

Story by Ellen T. Gray | Visualizations by Matthew R. Radcliff Released on May 15, 2012
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Witness an agricultural revolution take shape.
In the fields of the dry Texas panhandle, near the town of Dalhart, the traditional patchwork of working farms has been replaced by polka dots. This geometric transformation was sparked by a farming method called center-pivot irrigation, which pumps water through an extended sprinkler system that rotates like the hand of a clock, necessitating circular fields. Farmers around Dalhart have gradually adopted center-pivot irrigation since its introduction in 1949; it is ideal for the region's rolling, sandy terrain and delivers water with minimal loss to evaporation. The false-color, time-lapse images below show the square-to-circle revolution, as captured by four USGS-NASA Landsat satellites from 1972 to 2011. Red areas show healthy crops, while plots ranging in color from white to green represent bare soils and sparsely vegetated grasslands.
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With the spread of new irrigation systems, the total area of farmed land around Dalhart has grown over the last 40 years.
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By 2011, the revolution around Dalhart looks complete, as nearly all the agricultural fields have gone circular.
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In this true-color image, fields of dark green crops stand out from the surrounding, unfarmed landscape.
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A landscape dominated by center-pivot irrigation appears as a collection of pie charts, circles and half-moons.
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Sprinkler heads hang low over crops, delivering a direct, misty watering that minimizes evaporation and turns dry land into lush fields.

For More Information

NASA.gov

Story Credits

Lead Visualizer/Animator:
Matthew R. Radcliff (USRA)

Producer:
Matthew R. Radcliff (USRA)

Lead Writer:
Ellen T. Gray (ADNET Systems, Inc.)

Please give credit for this item to:
NASA's Goddard Space Flight Center
Aerial of the fields photo by John A. Kelley, USDA Natural Resources Conservation Service
Sprinkelrs photo by Gene Alexander, USDA Natural Resources Conservation Service

Short URL to share this page:
https://svs.gsfc.nasa.gov/10973

Keywords:
SVS >> App
NASA Science >> Earth