What Causes Drought? 7 Things (2024) You Need to Know

A drought designates a period when an area or region experiences below-normal precipitation either in the form of rain or snow.

This lack of precipitation can prompt numerous issues like reduced soil moisture or groundwater, diminished stream flow, crop damage, and a general water shortage.

It can be difficult to determine when a drought has started and ended.

They’re a costly weather event — the costliest, in fact, following hurricanes — and affect more people globally than any other natural disaster.

Here’s what you should know about the causes of drought and the steps you should take if your area is affected by one.

1. What is a drought?

A drought is a type of slow-onset natural disaster.

It’s characterized by the lack of precipitation.

Droughts can result in a serious water shortage that affects health, agriculture, economies, energy, and the environment.

Understanding how these dry spells can build in impact over time is critical.

Droughts occur naturally.

That said, human activity like water use and management can make drought conditions worse.

Furthermore, what may be considered a drought in one region won’t be considered a drought in another because of their weather patterns.

2. What are the types of droughts?

There are different types of droughts which are categorized based on how they developed and the impacts that they have.

Here are the three primary types you should know.

bulletMeteorological drought

This type of drought occurs when a region’s rainfall is short of what is expected.

bulletAgricultural drought

This type of drought occurs when water supplies are unable to meet the needs of crops or livestock at a particular time.

It can occur because of a meteorological drought as well as reduced access to water supplies or poor timing.

For example, if snowmelt occurs too early before runoff is most needed to hydrate crops, then an agricultural drought can occur.

bulletHydrological drought

This type of drought occurs when a lack of rainfall persists for the long period.

This lack of water will be enough to deplete surface water like rivers, reservoirs, or streams in addition to groundwater supplies.

3. What are the causes of this phenomenon?

There are several causes of droughts, and they are important to understand as this can help us prevent them.

bulletNatural causes

If you look back throughout history, you’ll know that droughts are nothing new.

They’ve long plagued humankind.

Until recently, droughts often occurred due to cyclical weather patterns like the amount of moisture and heat in the air, land, and sea.

bulletFluctuating ocean and land temperatures

Fluctuating ocean and land temperatures are a newer cause of droughts.

Ocean temperatures affect global weather patterns.

In fact, even tiny temperature fluctuations can impact climate systems.

Studies have demonstrated that dramatic and prolonged temperature changes in the North Pacific and North Atlantic Oceans correspond with extreme weather patterns on land.

These patterns include extreme droughts in North America and the Eastern Mediterranean.

Furthermore, changing ocean temperatures are also behind El Nino and La Nina weather phenomena.

La Nina, for instance, is known for drying out the southern United States.

bulletAltered weather patterns

The global rainfall distribution is affected by how air circulates throughout the atmosphere.

When there’s an irregularity in surface temperatures (particularly over the ocean), air circulation patterns change how and where precipitation falls.

This occurrence can reduce the amount of water available for crops in the summer if it causes less rain to fall in your area.

bulletReduced soil moisture

Soil moisture affects both cloud formation and precipitation.

Water from wet soil will evaporate, which helps form rain clouds.

This creates a cycle of returning water back to the earth.

If the land is drier than normal because of drought, then the moisture still evaporates into the atmosphere but not at a volume adequate to form rain clouds.

This causes the land to “bake” and remove additional moisture, further exacerbating dry conditions.

bulletManmade causes

Drought also has manmade causes.

Although droughts occur naturally, excessive water use can cause them to occur more often and be more intense.

bulletClimate change

Climate change affects droughts as well.

It causes rising global temperatures which makes wet regions wetter and dry regions drier.

In wet regions, warm air absorbs more water and leads to larger rain events.

In more arid regions, warmer temperatures mean water evaporates more quickly reducing soil moisture.

Furthermore, climate change can alter large-scale atmospheric circulation patterns, which can shift storms off their typical path and magnify weather extremes.

Climate models have predicted that already parched U.S. cities in both the U.S. Southwest and the Mediterranean will continue to get drier.

bulletExcess water demand

Droughts highlight an imbalance in the water supply and demand.

When a regional population booms, intensive agricultural water use can put a strain on water resources.

Human consumption of water also increases.

One study showed that human consumption over the 50 years from 1960 to 2010 has increased the frequency of drought by 25 percent in North America.

Furthermore, when rainfall decreases and drought conditions occur, persistent water demand from pumping groundwater, rivers, reservoirs, etc. can deplete valuable water resources that require years to replenish.

This means that future water availability is severely impacted.

Demand for water supplied by upstream lakes and rivers, particularly in the form of irrigation and hydroelectric dams, can dry out downstream water resources.

This can cause drought in other regions.

This delicate balance demonstrates just how critical it is to conserve water and keep your demand in check.

bulletDeforestation and soil degradation

Trees and plants release moisture into the atmosphere.

This allows clouds to form and return moisture to the ground as rain when they become too heavy.

If deforestation occurs, then less water is available to feed the water cycle.

This makes entire regions more vulnerable to drought.

Additionally, deforestation and poor land-use practices (like intensive farming) can diminish soil quality and reduce the land’s ability to absorb and retain water.

Thus, the soil dries out faster and groundwater isn’t replenished.

Both of these occurrences can result in different types of droughts.

Experts now believe that the 1930s Dust Bowl was caused by poor agricultural practices combined with the cooling of the Pacific and warming of the Atlantic.

A temperature difference of as little as a few tenths of a degree can make this difference and cause a drought.

4. Are droughts increasing?

Droughts increased by nearly 30% between 1998 and 2017.

It’s undeniable that temperatures across the world have become hotter and hotter conditions precipitate extreme weather.

Hotter conditions also reduce snowpack, and snowpack is an important source of water supply and natural water storage in various regions.

The driest parts of the world are now getting drier while the wettest parts of the world are getting wetter.

Certain regions of the world have endured longer and more intense droughts since the 1950s.

These include Southern Europe and Western Africa.

As temperatures continue to rise, researchers anticipate these trends intensifying.

5. What can you do to prevent droughts?

Unfortunately, we can’t control the weather, which largely impacts droughts.

That said, we can limit manmade climate change contributions, reduce water waste, and use water more efficiently.

These actions can help curb future dry periods.

6. How can you prepare for droughts?

Here are a few ways you can prepare for droughts:

bulletClimate change mitigation

Climate change can be mitigated when countries, cities, businesses, and individuals move away from using climate-warming fossil fuels and instead use clean renewable energy sources.

bulletUrban water conservation and efficiency

An estimated 2.1 trillion gallons of drinkable water is lost each year due to aging infrastructure in the U.S.

This aging infrastructure includes faulty meters, crumbling pipes, leaky water mains, etc.

A single leaky faucet can release just three drips a minute and waste more than 100 gallons of water in a year.

If cities and residents repair this infrastructure, they can boost water efficiency and reduce water use by as much as 60 percent.

bulletWater recycling

Recycled water (also known as reclaimed water) is highly treated wastewater that can be used for landscape irrigation, industrial processes, and so much more.

It replenished the groundwater supply and serves as a significant water resource.

One way to recycle water is to treat gray water.

Graywater is water from sinks, shower drains, and washing machines.

It can be used on-site for non-potable uses like garden or lawn irrigation.

Recycled water can serve as a significant water resource and reduce the demand for river, streams, reservoirs, and underground water supplies.

Water recycling is a key way to increase the water supply.

For instance, it could reintroduce as many as 750 billion gallons into the state of California by the year 2030.

bulletStormwater capture

The U.S. has about 10 trillion gallons of untreated stormwater going to waste every year.

It washes off the pavement and rooftops into sewer systems and waterways.

This creates pollution problems and reduces the amount of rainwater that can soak back into the earth for groundwater.

Green infrastructure — including green roofs, tree plantings, rain gardens, rain barrels, cisterns, and permeable pavement — can increase water supplies substantially.

Experts estimate that stormwater capture in urban Southern California and the San Francisco Bay area could increase annual water supplies by as much as 205 billion gallons.

bulletAgricultural water conservation and efficiency

Did you know that agriculture is the largest consumer of Earth’s available freshwater?

It accounts for 70 percent of water withdrawals worldwide.

If we want to conserve water in the face of drought, then the agricultural sector should focus on increasing water efficiency and reducing consumption.

One way to do this is through improved irrigation techniques.

If you switch from flood to drip irrigation, this can cut water usage by 60 percent.

Drip irrigation is also more precise and allows you to adjust the amount of water at different stages of crop growth.

Other techniques like crop rotation, no-till farming, and the use of crop cover to help build soil health also enable the land to absorb and retain more water.

These are important tools to remember if you use your land for agriculture.

7. When does a drought begin and end?

The precise timeline of a drought is difficult to determine.

Several weeks, months, and even years can pass before people realize that a drought is happening.

Additionally, a drought can end as gradually as it began.

The first evidence that a drought has begun is in rainfall records.

You’ll likely be able to see the effects of drought on flow in streams and reservoirs, but this may not be possible for several weeks or months.

In general, many people think that a drought ends when it rains.

And while it’s true that rainfall in any form helps provide drought relief, it doesn’t automatically end the drought.

Think about it in terms of medication and illness.

A single dose of medicine can help alleviate symptoms you’re feeling when you’re sick, but it isn’t necessarily going to cure you instantly.

Similarly, when it comes to a drought, a single rainstorm won’t break a drought.

It will, however, provide temporary relief.

“Soaking rains” are the best medicine for droughts.

You need water that enters the soil and recharges groundwater.

This will help feed streams and vegetation during periods when it isn’t raining.

Final Thoughts

While the causes of drought may seem beyond human control, there are ways that you can help mitigate the effects.

Do your best to combat climate change and conserve water.

Even if your area isn’t actively in a drought right now, taking these steps can help to keep your water resources at an adequate level.

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Erika Gokce Capital

Disclaimer: we are not lawyers, accountants or financial advisors and the information in this article is for informational purposes only. This article is based on our own research and experience and we do our best to keep it accurate and up-to-date, but it may contain errors. Please be sure to consult a legal or financial professional before making any investment decisions.


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