What is a drought?
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. It can have a massive impact on the ecosystem and agriculture of the affected region. Drought is a normal, recurring feature of the climate in most parts of the world. Having adequate drought mitigation strategies in place can greatly reduce the impact. Recurring or long-term drought can bring about desrtification. Generall, rainfall is related to the amount of water vapor in the atmosphere, combined with the upward forcing of the air mass containing that water vapor. If either of these are reduced, the result is drought.
- Above average prevalence of high pressure systems
- Winds carry continental, rather than oceanic air masses
- El Nino
- Some speculate that global warming will have a substantial impact on agriculture throughout the world, and especially in developing nation.
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 industrial users
- Sust storms
- Malnutrition, dehydration and related diseases
- Famine due to lack of water for irrigation
- Social unrest
- Mass migration, resulting in internal displacement and international refugees
- War over natural resources, including water and food
- Reduced electricity production due to insufficient available coolant
- Snakes have been known to emerge and snakebites become more common
Stages of drought
As a drought persists, the conditions surrounding it gradually worsen and its impact on the local population gradually increases. Droughts go through three stages before their ultimate cessation:
- Meteorological drought is brought about when there is a prolonged period with less than average precipitation. Meteorological drought usually precedes the other kinds of drought.
- Agricultural droughts are droughts that affect crop production or the ecology of the range. This condition can also arise independently from any change in precipitation levels when soil conditions and erosion triggered by poorly planned agricultural endeavors cause a shortfall in water available to the crops. However, in a traditional drought, it is caused by an extended period of below average precipitation.
- Hydrological drought is brought about when the water reserves available in sources such as aquifers, lakes and reservoirs falls below the statistical average. Like an agricultural drought, this can be triggered by more than just a loss of rainfall.