Drought - Types and Consequences

Drought - Types and Consequences

Drought is one of the natural disasters that is difficult to predict due to its slow process. Explain the consequences and types of droughts.

- Drought is a temporary reduction in water or moisture level, a dry weather. It is a condition when a region receives less than its average amount of rainfall for months or sometimes even years. It is a natural event which is caused by weather conditions like El Nino and high pressure systems, deforestation, global warming and by diverting rivers.

- Prediction of a drought is rather difficult since it usually happens slowly and its effects to last for a long time.

- Most tropical countries, on an average, experience a severe drought once in five years in most of the tropical countries.

- The hazard directly affects the deprived of the society making a lasting effect on life, economy, infrastructure, environment etc since these are linked together.

Following are the types of droughts-

(I) Meteorological drought: This is characterized by a significantly low rainfall than the climatological mean of the area. The entire country may receive normal rainfall, however, various meteorological districts and their sub divisions may experience rainfall below normal level.

Causes of meteorological drought:

(i) Scanty monsoon and below average rainfall.
(ii) Late beginning or early withdrawal of monsoons.
(iii) Prolonged interruption in monsoon.
(iv) Re-establishment of southern branch of jet stream.

(II) Hydrological drought: A significant reduction of surface water leading to very low stream flow and drying of lakes, rivers and reservoirs.

Causes of hydrological drought:

(i) Deforestation on a large scale
(ii) Mining
(iii) Over pumping of groundwater.

(III) Surface water drought: happens with drying up of surface water resources such as rivers, streams, lakes, ponds etc. Deforestation on a large scale is the main cause of surface water drought.

(IV) Ground-water drought: is associated with the sudden drop in the ground water level which happens due to excessive pumping of ground water creating somewhat irreversible ground water drought despite normal rainfall conditions.

(V) Agricultural drought: Insufficient soil moisture resulting in a subsequent acute crop produce and drop in agricultural productivity.

Causes of agricultural drought:

(i) Large scale use of HYV(High Yielding Varieties) seeds.
(ii) Change in pattern of cropping

Consequences of Drought:

i. Economic Impact: With a decline in the area of cultivation, there is a fall in the agricultural production. This results in reduction in secondary and tertiary activities with a decline in purchasing power.

ii. Environmental Impacts: Great damage is caused to plant and animal life. It affects the quality of air and water and causes forest fires. Meteorological droughts have an adverse impact on the recharge of soil moisture, surface runoff and ground water.

iii. Impacts on Society: Drought conditions triggering scarcity of drinking water, and food compel people to migrate in search of livelihood. Sometime dire conditions create suicidal tendencies.

Ways to deal with drought:

- Spreading knowledge about crops that are drought resistant and provide proper training for the same.

- Rainwater harvesting and inter-linking of rivers will prove effective in minimizing the effect of droughts.