Center Pivot Irrigation From Space
June 28, 2002
The above image, showing a colorful mosaic of crop circles, was acquired by the Landsat-7 Enhanced Thematic Mapper plus (ETM+) over southwestern Kansas (near Garden City) in September of 2000. This is a false-color composite image made using near infrared, red, and green wavelengths - it was enhanced using the ETM+ panchromatic band. Healthy croplands, mostly grain crops, including wheat, soybean and alfalfa, appear in red on the image. Center pivot irrigation systems are responsible for the circular fields. These huge systems provide an efficient means of getting irrigation water to crops. Because Mother Nature doesn't always produce the rain that's needed, center pivot systems can be used to pipe water to the thirsty crops. An advantage is that since the piping slowly rotates about a pivot point, water is evenly distributed on a regular basis. On this image, the cream-colored circles are fields which have already been harvested, and the bluish-green areas are non-cultivated lands. Center pivot systems can also be used to uniformly apply pesticides.