Drought is a condition that arises due to lack or insufficiency of rain for a long duration. The main causes of drought are: water shortage, stream flow reduction or depletion of groundwater and soil moisture. It is an indirect but gradual hazard occurring in Nature that affects agriculture. It can be categorised into four basic kinds:
Permanent: It occurs in dry climatic zones.
Seasonal: It occurs in those climatic zones that experience short annual rainfall and have prolonged dry seasons.
Unpredictable: It can occur due to an abnormal rainfall failure.
Invisible: It occurs when the rate of evaporation is high.
