The same is not at all a rare phenomenon, with the memories of the 'Dust Bowl' - a severe drought which occurred in the United States in 1930s, still haunting the Americans.
Similar occurrences have also been recorded from various other parts of the world, with the ongoing drought in Australia, referred to as the 'Big Dry', being one of the most recent examples of this phenomenon.
Though quite common, drought continues to be one of the least known weather phenomena for the layman because of the widespread ignorance about some of the most obvious facts about it.
The levels of ignorance are such that most of the people out there don't know that drought and famine are two different concepts, with the term 'famine' referring to severe shortage of food caused as a result of crop failure due to drought. Here is more information on this weather phenomenon which will help you do away with all the myths about it.
What is a Drought?
A drought refers to the extended period wherein a region records severe deficiency in water supply, - with lack of precipitation acting as the most prominent trigger for the same. While this definition does underline the basics of this weather phenomenon, the same can be defined on the basis of meteorological, agricultural and hydrological attributes too.
In meteorology, a drought is a prolonged period with less than average precipitation. In agricultural sense, it is dry spell which affects crop production. And in hydrology, it is fall in water levels of various sources below the statistical average. While a drought can extend for years, even a short drought can have serious consequences on the whole region.
What Causes a Drought?
While lack of precipitation does act as a trigger for drought, one has to take into consideration what causes this shortage of precipitation when discussing the causes of drought. Precipitation happens to be one of the three steps of water cycle, with the other two being evaporation and condensation.
If either of these three water cycle attributes are hampered, it tends to affect the other two which are directly dependent on it. Evaporation of water from oceans is half task done, as the water vapor that is formed by this has to be carried over to the land by the wind.
If the wind is not strong enough, it won't be able to carry the moisture required for the formation of clouds to the interior regions.
Similarly, mountains can also act as barriers when it comes to movement of these moisture carrying winds. That explains why the windward side of mountain experiences more rainfall as compared to the leeward side (and why leeward sides are so drought prone and vulnerable to desertification).
At the same time, the biggest hindrance to the process of condensation happens to be the prevalence of high pressure system which can be attributed to jet streams in the upper atmosphere and warm and cold water currents in the oceans.
A region also becomes vulnerable to drought when extensive agriculture, deforestation, etc. affect the ability of the soil to retain moisture.
What are the Effects of a Drought?
As we mentioned earlier, even a short drought can result in severe consequences on the environment as well as the economy of the region. It is but obvious that water is a basic necessity for the survival of lifeforms, and therefore if the same is not available in the required amount, it is bound to come heavy on the environment.
At the same time, scarcity of food along with mass dying of animals causes conditions which are conducive for the spread of diseases. Some of the most common health issues that are attributed to food scarcity caused as a result of drought happen to be malnutrition and dehydration.
Alongside water shortage, crop failure during a drought is also attributed to the fact that the quality of soil is severely diminished during this period. This soil doesn't just lack moisture, but also lacks organic matter which makes it fertile. Frequency of dust storms increases due to drought as soil which lacks moisture tends to erode easily.
If the drought continues to exist for a prolonged duration, it can result in desertification of the region. When water sources start depleting, the lifeforms which inhabit these water sources start dying - predominantly due to loss of habitat and increased competition.
While the obvious effects of drought are most often seen on the agriculture sector, a drought can also come heavy on industries like the fisheries, power generation, etc.
Taking into consideration the effects of a drought, its prevention becomes a necessity. But is it possible? To prevent a drought, it has to be predicted, and predicting a drought is next to impossible as it builds up slowly over the course of time.
Steps for prevention of drought mostly revolve around ensuring that we don't contribute to the underlying causes of the same, knowingly or unknowingly, and that is something which can be done by resorting to simple measures such as using water and other natural resources responsibly, not resorting to foul agricultural practices and deforestation, etc.