ESS124
Prof.
Jin-Yi Yu
Definition of Drought
•Worldwide, drought leads to more fatalities than any other
weather phenomenon.
•There is no
universal definition of drought.
•A meteorological
or clmatological drought refers to an unusual long period during which precipitation is below normal
for a particular area.
•Hydrological drought describes an unusual deficiency of
groundwater and/or
stream flow, i.e., water levels are below normal for the area.
•Agricultural drought refers to a period of deficient moisture
in the soil layer from
which crops and other plants normally draw their water.
•Socio-economic drought occurs when the moist shortage is
sufficiently large
that it affects people.
•Agricultural drought often proceeds hydrological drought, and
soci-economic
drought generally lags other types of droughts.