A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation.There is no clear cut demarcation that can define a drought. Droughts can be of three kinds:-
(i) Meteorological drought: This happens when the actual rainfall in an area is significantly less than the climatological mean of that area. The rainfall categories for smaller areas are defined by their deviation from a meteorological area’s normal rainfall Excess: 20 per cent or more above normal Normal: 19 per cent above normal – 19 per cent below normal Deficient: 20 per cent below normal – 59 per cent below normal Scanty: 60 per cent or more below normal The country as a whole may have a normal monsoon, but different meteorological districts and sub-divisions can have below normal rainfall.
(ii) Hydrological drought: A marked depletion of surface water causing very low stream flow and drying of lakes, rivers and reservoirs
(iii) Agricultural drought: Inadequate soil moisture resulting in acute crop stress and fall in agricultural productivity Earlier years of All-India drought 1987, 1979, 1972.
Periods of drought can have significant environmental, economic and social consequences. The most common consequences include:
Death of livestock.
Reduced crop yields.
Shortages of water for domestic and industrial users.
Malnutrition, dehydration and related diseases.
Famine due to lack of water for irrigation.