What is Drought?
An extended period of unusually dry weather with scanty rainfall is usually referred to as a drought. However, this is not the absolute definition of a drought, as its nature and definition varies from region to region. Droughts usually result in significant shortages in a region’s water supply, an occurrence induced by a depletion of atmospheric water vapor, surface water, and underground water as well. Unlike most other natural disasters like earthquakes, volcanic eruptions, or massive floods, determining the starting time of a drought can be quite tricky. Droughts can also last for variable periods of time, from weeks to a few years to entire decades.
Types of Drought, Classified by Cause
Droughts are usually the result of changes in regular weather patterns. Changes in atmospheric circulation stalling storm tracks lowers the precipitation over land, triggering conditions of drought as a result. The El Nino and La Nina phenomena are also often regarded as culprits responsible for droughts. Recently, it is believed that anthropogenic activities might also be instrumental in inviting droughts with unprecedented frequency and severity. For example, excessive extraction of water for irrigation of land and domestic consumption can often disturb the water cycle significantly, creating a period of dry spells. A section of scientists also claim that climate change will also result in the enhancement of drought conditions across certain parts of the world.
Impact of Droughts
In areas of the world where droughts are common, the native flora and fauna are usually adapted to survive under these dry conditions. However, when droughts exist for extremely long periods of time, vegetation is compelled to die out completely due to a lack of water, and the entire food chain is thus disturbed. Hence, biodiversity loss is quite common during severe drought conditions. Soil erosion also increases during such periods, as a lack of vegetation cover exposes the soil to the wind. Wildfires also become common during droughts. Droughts have a significantly detrimental impact on the human societies residing in the areas experiencing drought. Famines are quite common in drought-stricken areas, as agriculture is impeded and livestock die due to a lack of vegetation upon which to graze. Land prices plummet downward in drought-prone areas, and people are often forced to flee such lands just to survive.
Major Droughts in Recent History
In the 1930s, the U.S. suffered an intensive period of drought known as the “Dust Bowl”, referring to the massive clouds of dust and dry eroded soil that persisted in the air for days at a time. The drought had a severe impact on the country’s economy, as it affected the production quality of over 50 million acres of land. 2.5 million people were forced to migrate from the Great Plains region into other parts of the country, further disrupting the country’s economy due to the sudden drastic shifts in demographic patterns. Droughts again affected the Great Plains region in the 1950s and in the 1980s, with the latter costing the U.S. economy a loss of nearly $39 billion USD. Australia also experiences frequent periods of drought, such as the "Big Dry" and the "Millennium Drought". Droughts in Africa have a much more sinister impact since, combined with other problems in the region's countries like extreme poverty and a burgeoning population pressures, the African droughts kill thousands of Africans. For example, the droughts that affected the Sahel region of Africa in the 1970s and 1980s killed more than 100,000 people, and forced millions more to flee their homelands. The Horn of Africa (Eritrea, Ethiopia, Somalia, and Djibouti) is especially susceptible to droughts. As recently as 2011, droughts in the region claimed the lives of 100,000 people, and adversely impacted the lives of over 13 million others.
Future casualties arising from droughts are predicted to be much higher than historical figures. The burgeoning human population will starve the planet of its fresh water resources. Climatic influences triggering droughts will thus result in even greater shortages of water for the still growing human population. Global warming will further catalyze the drought conditions, causing droughts to become more common all across the world. It is thus highly important that people and governments across the planet develop and adopt new practices and policies that will help human society prevent, mitigate, and prepare for the possibilities of worsened future droughts as much as possible.