Parameter Tree:
EARTH SCIENCE SERVICES > ENVIRONMENTAL ADVISORIES > AGRICULTURAL ADVISORIES > DROUGHT FORECAST

Definition:
Drought is a protracted period of deficient precipitation resulting in
extensive damage to crops, resulting in loss of yield.
Lack of rainfall for an extended period of time can bring farmers and major
metropolitan areas to their knees. It does not take very long; a few rain-free
weeks spreads panic and shrivels crops. A drought forecast would be issued for
one of the following:


Meteorological - a measure of departure of precipitation from normal. Due to
climatic differences what is considered a drought in one location may not be a
drought in another location.


Agricultural - refers to a situation when the amount of moisture in the soil no
longer meets the needs of a particular crop and can also affect livestock and
other dry-land agricultural operations.


Hydrological - occurs when surface and subsurface water supplies are below
normal.


Socioeconomic - refers to the situation that occurs when physical water
shortage begins to affect people.



Reference:
http://drought.unl.edu/

http://www.droughtoutlook.com/