A Vegetation Greenness "Difference" Map
| Sometimes growing conditions are less than ideal, such as during drought years or years that experience extreme weather conditions. In this case, growers need a way to compare the performance of their crops to the long-term average. To make this comparison, the GreenReport analyzes current crop conditions (NDVI values) against a long-term greenness average, producing a map called Greenness Difference Map 3. In this example, crop conditions from mid-July, 2000 are compared to the average crop conditions for mid-July during the past 10 years. Dark green areas show that crops were more developed in mid-July 2000 compared to the long-term average. Yellow areas on the map indicate vegetation that is not as green as the average. In this map, spring wheat within area 1 is developing much ahead of the average for this time of year. In area 2, corn and soybeans were developing slightly ahead of the average. Mixed croplands in area 3 developed well ahead of the average, while area 4 developed close to the average. Another interesting feature of this map is the variability in vegetation and crop conditions across the eastern region of the U.S. and southern Canada, while the arid regions of the west (which have sparser vegetation) show far less variability over the long-term. |
Credit: Kansas Applied Remote Sensing/NASA
For more info: http://www.kars.ukans.edu/products/greenreport.htm