CIR Interpretation Tutorial
Non-Urban Land Use in Virtual Nebraska
Non-urban land use in Nebraska consists mostly of farming activities and the recreational use of public land. The latter use cannot easily be represented here by an example. For example, it would be extremely difficult, if not impossible, to provide an image of a very good fishing spot. However, farming activities do create highly distinctive features that can be easily seen in the Virtual Nebraska images.
In the above image, much of the area immediately surrounding Oshkosh is in agricultural production. This can easily be determined by observing the farm fields that dominate the image. Some of these fields appear to be under production. This is illustrated by the presence of healthy vegetation on the farms. In this type of image, healthy vegetation is being represented by red areas. Bluish rectangular and circular features can also be seen in the image; these are fields that are probably bare and have either been harvested, or they are being prepared for planting. The circular features in the image are center-pivot irrigation systems. Most center-pivots irrigate approximately one quarter-section (160 acres/64.75 hectares). A red center-pivot would indicate that a crop is being grown and irrigated. A bluish-toned center-pivot indicates that there is currently not much vegetation there. the alternating stripes that are in the one center-pivot are proabably there to reduce wind erosion. Likewise too are some of the alternating strips of vegetated cover in the rectangular-shaped fields.
Crop types could be monitored from above the ground using either airborne or satellite image data. As long as one had a crop calendar and enough image data to cover the growing season, one could determine when fields had been planted, the crops harvested, and the when the fields were replanted.