Brief overview
Drylands are inhabited by over two billion people worldwide. As lands that sometimes are poorly understood and thought of as unproductive and barren, they support nearly 40 percent of the world’s population. The distribution patterns of these dryland populations vary within each region and among the aridity zones comprising drylands. A global map of population densities within drylands and a table of the number of people living in drylands within each of the world’s regions provide tools to examine these patterns.
Map 3Population Density in Drylands
Map description
Regionally, Asia has the largest population living in drylands, both in terms of numbers and percent: over 1.4 billion people, or 42 percent of the region’s population. Africa has nearly the same percent of people living in drylands – 41 percent – although the total number is less than Asia’s: nearly 270 million. South America has 30 percent of its population in drylands or approximately 87 million people (Table 4).
Of the three aridity zones defining drylands, semi-arid and dry sub-humid lands are favored, with population levels rising with increases in humidity. Some of the highest population densities in the world are found in the semi-arid and dry sub-humid zones of India. Other pockets of high population densities occur in the dry sub-humid zones of eastern China, the Middle East, and West Africa.
Sources
CIESIN. 2000. Center for International Earth Science Information Network (CIESIN), Columbia University, International Food Policy Research Institute (IFPRI), and World Resources Institute (WRI). 2000. Gridded Population of the World, Version 2 Alpha. Palisades, NY: CIESIN and Columbia University. Data available online at: .
UNSO. 1997. Office to Combat Desertification and Drought. Aridity Zones and Dryland Populations: an Assessment of Population Levels in the World’s Drylands. New York: UNSO/UNDP. 23pp.
