
Aridity is the condition of geographical regions which make up approximately 43% of total global available land area, characterized by low annual precipitation, increased temperatures, and limited water availability.
[Perez-Aguilar, L. Y., Plata-Rocha, W., Monjardin-Armenta, S. A., Franco-Ochoa, C., & Zambrano-Medina, Y. G. (2021). The Identification and Classification of Arid Zones through Multicriteria Evaluation and Geographic Information Systems—Case Study: Arid Regions of Northwest Mexico. ''ISPRS International Journal of Geo-Information'', ''10''(11), 720. https://doi.org/10.3390/ijgi10110720] These areas tend to fall upon degraded soils, and their health and functioning are key necessities of regulating ecosystems’ atmospheric components.
Change over time
The distribution of aridity at any time is largely the result of the general circulation of the
atmosphere
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...
. The latter does change significantly over time through
climate change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
. For example, temperature increase by 1.5–2.1 percent across the
Nile Basin
The Nile Basin is the part of Africa drained by the Nile River and its tributaries.
Besides being the second largest hydrographic basin in Africa, the Nile Basin is effectively the most notable drainage basin on the continent. It covers approxi ...
over the next 30–40 years could change the region from
semi-arid
A semi-arid climate, semi-desert climate, or steppe climate is a aridity, dry climate sub-type. It is located on regions that receive precipitation below Evapotranspiration#Potential evapotranspiration, potential evapotranspiration, but not as l ...
to arid, significantly reducing the land usable for
agriculture
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
. In addition, changes in land use can increase demands on soil water and thereby increase aridity.
A December 2024 report from the
UNCCD concluded that more than three-quarters of the Earth's land "has become permanently dryer in recent decades", that "drier climates now affecting vast regions across the globe will not return to how they were", and that a quarter of the global population lives in expanding drylands.
See also
*
Arid Forest Research Institute
Arid Forest Research Institute (ICFRE-AFRI) is a research institute situated in Jodhpur, Rajasthan, India. The institute conducts scientific research in forestry in order to provide technologies to increase the Permanent vegetative cover, vege ...
*
Aridity index
An aridity index (AI) is a numerical indicator of the degree of dryness of the climate at a given location. The American Meteorological Society defined it in meteorology and climatology, as "the degree to which a climate lacks effective, life-promo ...
*
Desiccation tolerance
Desiccation tolerance refers to the ability of an organism to withstand or endure extreme dryness, or drought-like conditions. Plants and animals living in arid or periodically arid environments such as temporary streams or ponds may face the chall ...
*
Drought
A drought is a period of drier-than-normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, ...
*
Humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog t ...
*
Vapor pressure
Vapor pressure or equilibrium vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. The equilibrium vapor pressure is an indicat ...
References
External links
* Griffiths, J. F. (1985) 'Climatology', Chapter 2 in ''Handbook of Applied Meteorology'', Edited by David D. Houghton, John Wiley and Sons, .
* Durrenberger, R. W. (1987) 'Arid Climates', article in ''The Encyclopedia of Climatology'', p. 92–101, Edited by J. E. Oliver and R. W. Fairbridge, Van Nostrand Reinhold Company, New York, .
* Stadler, S. J (1987) 'Aridity Indexes', article in ''The Encyclopedia of Climatology'', p. 102–107, Edited by J. E. Oliver and R. W. Fairbridge, Van Nostrand Reinhold Company, New York, .
Blue Peace for the Nile Report 2009, Strategic Foresight Group
{{Authority control
Climate patterns
Soil science
Water scarcity