Coincidence or Lack of Coincidence between Meteorological and Agricultural Droughts

Drought is a natural disaster which can lead to human and economic losses.
This phenomenon takes place under different climatical systems. There is not a general agreement on the definition of drought, because the definitions depend on different specialists as they have been pointed to meteorological, hydrological and agricultural droughts in scientific references.
Meteorological drought is experienced only when rainfall deviates appreciably below normal. Hydrological drought is referred to as periodical shortage of water resources for different reasons in a given time. Agricultural drought is caused by an inadequate availability of soil - water over a critical period, and this condition also depends on plant species and soil types. This study has focused on coincidence or lack of coincidence between meteorological and agricultural droughts. To do this, meteorological and phenological data from agricultural meteorology research station in SRARUD - KERMANSHAH during 1990-91 to 1998-99 (except for 1993-94 when field has not been cultivated) have been used. Results show that agricultural drought was coincident with meteorological drought, and this has occurred even during wet years, for example during 1994-95 and 1997-98 agricultural years.