定義
Regions of moderately low rainfall, which are not highly productive, usually classified as rangelands. "Moderately low" is widely accepted as between 100 and 250 mm of precipitation per year. (Source: IPCC, 2007)
Regions that have between 10 to 20 inches of rainfall and are capable of sustaining some grasses and shrubs but not woodland. (Source: GEMET/TOE / DOE)
Concept URI: http://www.informea.org/terms/semi-arid-zone