#Drought_Classification
✅1. Based on duration
🔘(a) Permanent drought - This is characteristic of the desert climate where sparse vegetation grow-
ing is adapted to drought and agriculture is possible only by irrigation during entire crop season.
🔘(b) Seasonal drought - This is found in climates with well-defined rainy and dry seasons. Most of
the arid and semiarid zones fall in this category. Duration of the crop varieties and planting dates
should be such that the growing season should fall within rainy season.
🔘(c) Contingent drought - This involves an abnormal failure of rainfall. It may occur almost any-
where especially in most parts of humid or sub humid climates. It is usually brief, irregular and
generally affects only a small area.
🔘(d) Invisible drought - This can occur even when there is frequent rain in an area. When rainfall is
inadequate to meet the evapotranspiration losses, the result is borderline water deficiency in soil
resulting in less than the optimum yield. This occurs usually in humid regions.
✅2. Based on nature of the users (NCA, 1976)
🔘(a) Meteorological drought - It is defined as a condition, where the annual precipitation is less than
the normal over an area for prolonged period (month, season or year).
🔘(b) Atmospheric drought - It is due to low air humidity, frequently accompanied by hot dry winds.
It may occur even under conditions of adequate available soil moisture. It refers to a condition .
when plants show wilting symptoms during the hot part of the day, when transpiration exceeds absorption temporarily for a short period. When decreases, absorption keeps pace with transpi-ration and plants revive (mid day wilt).
🔘(c) Hydrological drought - Meteorological drought, when prolonged results in hydrological drought with depletion of surface water and consequent drying of reservoirs, tanks etc. It results in
deficiency of water for all sectors using water. This is based on water balance and how it affects irrigation as a whole for bringing crops to maturity.
🔘(d) Agricultural drought - It is the result of soil moisture stress due to imbalance between available
soil moisture and evapotranspiration of a crop. It is usually gradual and progressive. Plants can therefore, adjust at least partly, to the increased soil moisture stress. This situation arises as a consequence of scanty precipitation or its uneven distribution both in space and time. It is also usually referred as soil drought
T.me/agriguruji
✅1. Based on duration
🔘(a) Permanent drought - This is characteristic of the desert climate where sparse vegetation grow-
ing is adapted to drought and agriculture is possible only by irrigation during entire crop season.
🔘(b) Seasonal drought - This is found in climates with well-defined rainy and dry seasons. Most of
the arid and semiarid zones fall in this category. Duration of the crop varieties and planting dates
should be such that the growing season should fall within rainy season.
🔘(c) Contingent drought - This involves an abnormal failure of rainfall. It may occur almost any-
where especially in most parts of humid or sub humid climates. It is usually brief, irregular and
generally affects only a small area.
🔘(d) Invisible drought - This can occur even when there is frequent rain in an area. When rainfall is
inadequate to meet the evapotranspiration losses, the result is borderline water deficiency in soil
resulting in less than the optimum yield. This occurs usually in humid regions.
✅2. Based on nature of the users (NCA, 1976)
🔘(a) Meteorological drought - It is defined as a condition, where the annual precipitation is less than
the normal over an area for prolonged period (month, season or year).
🔘(b) Atmospheric drought - It is due to low air humidity, frequently accompanied by hot dry winds.
It may occur even under conditions of adequate available soil moisture. It refers to a condition .
when plants show wilting symptoms during the hot part of the day, when transpiration exceeds absorption temporarily for a short period. When decreases, absorption keeps pace with transpi-ration and plants revive (mid day wilt).
🔘(c) Hydrological drought - Meteorological drought, when prolonged results in hydrological drought with depletion of surface water and consequent drying of reservoirs, tanks etc. It results in
deficiency of water for all sectors using water. This is based on water balance and how it affects irrigation as a whole for bringing crops to maturity.
🔘(d) Agricultural drought - It is the result of soil moisture stress due to imbalance between available
soil moisture and evapotranspiration of a crop. It is usually gradual and progressive. Plants can therefore, adjust at least partly, to the increased soil moisture stress. This situation arises as a consequence of scanty precipitation or its uneven distribution both in space and time. It is also usually referred as soil drought
T.me/agriguruji