Deserts are regions of our planet where it doesn't usually rain much. To give you an idea, the average rainfall (rain) in the desert is 250 mm per year, while in the Amazon, for example, it rains an amount close to 2500 mm per year. It's a big difference!
We're used to thinking of deserts always as very hot and arid places, aren't we? But this is not always true, as deserts can have medium temperatures, such as the Gobi Desert in China, and others can be true ice covers, such as the Antarctica, which is considered the largest desert in the world. These are called cold deserts.
In the case of hot deserts, the largest and best known in the world is the Sahara, located in the African continent. The Sahara has approximately nine million square kilometers, an area larger than that of the Brazilian territory. In addition, it is getting bigger as nature exploration activities in the surrounding areas are causing the ground become unprotected and the desert space increases.
Hot deserts (those driest and hottest) are not hot all the time. The lack of humidity in the air makes it difficult to conserve the heat emitted during the day, which is why the nights are colder. To make matters worse, sand is an element that loses and gains heat very quickly (have you noticed that during the day the sand on beaches gets hot and burns our feet?). For this reason, during the day, temperatures reach 50°C, but at night, thermometers register, in some cases, down to -10°C!
The extreme conditions of deserts, especially the hot ones, mean that they are not very inhabited. But even so there are some species, mainly of vegetables, that bravely resist these bad situations. Cacti, for example, as they are xerophilic plants (which adapt to drought and humidity), have the incredible ability to conserve water within itself, in addition to having no leaves, reducing the perspiration. Some animals, such as small reptiles, can also survive in some deserts..
There is a desert known to be very “treacherous”, it is the Kalahari Desert in southern Africa. In it, for about three months, it rains a little and the landscape quickly changes, forming small lakes and some trees and woods. For this reason, unsuspecting people and animals may find that there are many resources there. However, suddenly, the drought presents itself and all that beautiful landscape is transformed, gaining the typical contours of hot deserts, with little food and water. Even so, there are native peoples who can live in this place, as they are used to it.
Deserts, despite causing fear in people, are natural and very beautiful areas. However, the regions around them need to be better conserved as they are expanding in some places in the world, harming the soils and the economic and social practices of the people who live in these places.
By Me. Rodolfo Alves Pena