03 Oct 2012:
NASA Map Illustrates
Effects of Drought on U.S. Vegetation
A new NASA map shows the major effects of this summer’s record droughts
on vegetation across much of the U.S., leaving a swath of parched earth that caused a shortage of food for wild and domesticated
animals alike. In the map, which shows the contrast between plant health during August and the average conditions for the month from 2002 to 2012, a vast brown area from the Rocky Mountains to the Ohio River valley illustrates regions where plant growth was below normal. The map is based on satellite data fed into the so-called Normalized Difference Vegetation Index, which measures the extent to which plant leaves absorb visible light and reflect infrared light. Drought-impacted vegetation reflects more light than healthy vegetation. “I am struck by the extraordinary depth and spatial scale of this drought,” said Molly Brown, a vegetation and food security researcher with NASA. “There is very little fodder out there for animals to eat.” Almost two-thirds of the contiguous U.S. experienced some level of drought by the end of August, with 39 percent of the nation enduring severe to extreme drought, according to the U.S. Drought Monitor.