The drought of 2012 has gone from bad to worse this summer as relentlessly hot and dry conditions continue to dominate the central United States.
Once drought takes hold of a region, it tends to feed on itself in a vicious cycle. To start, high temperatures increase evaporation rates causing the soil to dry out. Without plentiful rain to replace the moisture, the sun’s energy heats the ground and the air even further. The parched ground is then unable to support healthy vegetation that would release moisture into the air through transpiration. Humidity levels then drop and the air becomes even less able to produce rain, making the affected area even drier.
To break this cycle, a drought stricken region needs more than a few spotty showers. It requires drenching rains on a regular basis. Alas, these are not in the forecast for America’s desiccated heartland.
Image Credit: Agriculture Emergency Report