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Aridity is different from drought because aridity is permanent whereas drought is temporary. [1] A number of aridity indices have been proposed (see below); these indicators serve to identify, locate or delimit regions that suffer from a deficit of available water, a condition that can severely affect the effective use of the land for such ...
For example, temperature increase by 1.5–2.1 percent across the Nile Basin over the next 30–40 years could change the region from semi-arid to arid, significantly reducing the land usable for agriculture. In addition, changes in land use can increase demands on soil water and thereby increase aridity. [6]
Aridification is the process of a region becoming increasingly arid, or dry.It refers to long term change, [1] rather than seasonal variation. It is often measured as the reduction of average soil moisture content.
Desertification is a gradual process of increased soil aridity.Desertification has been defined in the text of the United Nations Convention to Combat Desertification (UNCCD) as "land degradation in arid, semi-arid and dry sub-humid regions resulting from various factors, including climatic variations and human activities."
There is a significantly greater proportion of drylands in developing countries (72%), and the proportion increases with aridity: almost 100% of all hyper-arid lands are in the developing world. Nevertheless, the United States , Australia , and several countries in Southern Europe also contain significant dryland areas.
Each image tile covers a 3.75 x 3.75 minute quarter quadrangle plus a 300-meter buffer on all four sides. CCMs are generated by compressing DOQQ image tiles into a single mosaic. All individual tile images and the resulting mosaic are rectified in the UTM coordinate system, NAD 83, and cast into a single predetermined UTM zone. [1]
The E-agriculture in Action series of publications, by FAO-ITU, that provides guidance on emerging technologies and how it could be used to address some of the challenges in agriculture through documenting case studies. E-agriculture in Action: Big Data for Agriculture [22] E-agriculture in Action: Blockchain for Agriculture [23]
For example, deforestation reduces the quantity of plants that may anchor soil and protect it from erosion, whereas overgrazing depletes vegetation and exposes soil to erosion and degradation. [20] For instance, it has been argued that the Sahara's edges are primarily the result of human activity, with climate playing merely a supporting role.