Kõrbepiirkondi

Kõrbepiirkondi, or arid regions, are characterized by extremely low precipitation levels. These areas receive less than 250 millimeters (10 inches) of rainfall annually, making them inhospitable for most plant and animal life. Deserts cover roughly one-fifth of the Earth's land surface and can be found on every continent. Their formation is often linked to global atmospheric circulation patterns, such as subtropical high-pressure zones which create descending dry air, or by rain shadow effects where mountain ranges block moisture from reaching leeward areas.

The landscape of kõrbepiirkondi varies greatly. While sand deserts with vast dunes are common in popular imagination, other types include rocky deserts, gravel plains, and salt flats. The extreme temperatures are also a defining feature, with diurnal temperature ranges often being very large. Daytime temperatures can soar, while nights can become surprisingly cold due to the lack of cloud cover to retain heat. Despite the harsh conditions, many species have adapted to survive in these environments, exhibiting specialized physiological and behavioral traits. These adaptations include water conservation mechanisms, nocturnal activity, and the ability to withstand extreme temperatures. Human populations in arid regions are often concentrated around scarce water sources like oases or rivers, and historically, these areas have been central to nomadic pastoralism and trade routes.