Deserts
Deserts are perhaps one of the most difficult places to live. The main characteristic of deserts is that they are extremely dry. Because humans need so much water, surviving in deserts is very difficult. Not only is it difficult for humans to survive in deserts - it is also hard for animals, plants and other forms of life to live. This, in turn, makes it even harder for human life to persist because there is always risk of running out of food.
It is surprising, then, that deserts cover about one fifth of the world's land! Furthermore, over one billion people (one seventh of the world's population) live in deserts!
How is this possible, and how do people overcome the challenges?
It is surprising, then, that deserts cover about one fifth of the world's land! Furthermore, over one billion people (one seventh of the world's population) live in deserts!
How is this possible, and how do people overcome the challenges?
What is a desert?
It is clear, then, that life in deserts is possible, but humans have had to adapt to the demands of surviving in deserts. Here are some of the ways people survive:
- A desert is a place that receives under 25 cm of rain per year.
- Deserts are part of a wider classification of regions called "drylands." These areas often lose more moisture through evaporation than they receive from annual precipitation.
- The largest hot desert in the world, northern Africa's Sahara, reaches temperatures of up to 50 degrees celsius.
- Not all deserts are hot! Some deserts are always cold, like the Gobi desert in Asia and the desert on the continent of Antarctica. Others are mountainous.
- Only about 10 percent of deserts are covered by sand dunes.
- The driest deserts get less than half an inch (one centimeter) of precipitation each year, and that is from condensed fog not rain.
- "Desert animals have adapted ways to help them keep cool and use less water. Camels, for example, can go for days without food and water. Many desert animals are nocturnal, coming out only when the brutal sun has descended to hunt. Some animals, like the desert tortoise in the southwestern United States, spend much of their time underground. Most desert birds are nomadic, crisscrossing the skies in search of food. Because of their very special adaptations, desert animals are extremely vulnerable to introduced predators and changes to their habitat." (National Geographic)
- Desert plants can last years without water, but some plants grow very long roots that reach all the way down to deep underground water. Cacti have special ways of storing water. Some desert plants can even live to be hundreds of years old.
It is clear, then, that life in deserts is possible, but humans have had to adapt to the demands of surviving in deserts. Here are some of the ways people survive:
- Wells are built in order to tap ground water. Some people even follow elephants to water sources because elephants can sniff out ground water. Plants are also a good source of water.
- Animals can be hunted and eaten.
- People have become experts at building shelter in deserts. Mud is often used to make brick and can be quite insulating. People also avoid working during the hot daylight hours.
- Savannah and grassland areas on the edges of deserts can be quite fruitful.
- Nomadic peoples wear special clothing that helps protect them from the heat. They also shield their eyes from sand storms with special fabrics.
- Irrigation canals are used to transport water from wetter regions to drier areas. Irrigation has been used for thousands of years.
- Technology has allowed people access to tools that make life easier. Extreme examples of desert survival are the cities of Dubai (below) and Las Vegas. Both are built in deserts, and both rely on imported goods and technology to sustain life. Technology can also help people to manipulate their surroundings and the conditions under which they live. For example, indoor facilities can mimic ideal climate areas. It's incredible what luxuries money can buy!
Here is an interactive map of the world's main desert regions!