drought desertification - United Nations Economic Commission for ...

SECTION 2:
Overview of drought and
desertification situation
in Africa
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10. Drought and desertification are at the core of serious challenges and threats facing sustainable
development in Africa. These problems have far reaching adverse impacts on human health, food security,
economic activity, physical infrastructure, natural resources and the environment, and national and global
security.
11. Although drought has several definitions, the central element in these definitions is water deficit. In
general, drought is defined as an extended period – a season, a year, or several years – of deficient rainfall
relative to the statistical multi-year average for a region. 1 This deficiency results in a water shortage for
some activity, group, or environmental sector. A more in-depth definition of drought includes four sub
definitions including meteorological, hydrological, agricultural and socio-economic drought.
12. Desertification on the other hand is defined as a process of land degradation in arid, semi-arid and
dry sub-humid areas, resulting from various factors, including climatic variations and human activities. 2
Land degradation manifests itself through soil erosion, water scarcity, reduced agricultural productivity,
loss of vegetation cover and biodiversity, drought and poverty.
2.1 Causes of drought and desertification
13. The underlying cause of most droughts can be related to changing weather patterns manifested
through the excessive build up of heat on the earth’s surface, meteorological changes which result in
a reduction of rainfall, and reduced cloud cover, all of which results in greater evaporation rates. The
resultant effects of drought are exacerbated by human activities such as deforestation, overgrazing
and poor cropping methods, which reduce water retention of the soil, and improper soil conservation
techniques, which lead to soil degradation.
14. Desertification is caused by multiple direct and indirect factors. It occurs because drylands
ecosystems are extremely vulnerable to over-exploitation and inappropriate land use that result in
underdevelopment of economies and in entranced poverty among the affected population. Whereas
over cultivation, inappropriate agricultural practices, overgrazing and deforestation have been previously
identified as the major causes of land degradation and desertification, it is in fact a result of much deeper
underlying forces of socio-economic nature, such as poverty and total dependency on natural resources
1 NASA Earth Observatory. Drought: The creeping disaster. http://earthobservatory.nasa.gov/Library/DroughtFacts/printall.php
2 The United Nations Convention to Combat Desertification in Those Countries Experiencing Serious Drought and/or Desertification,
Particularly in Africa (UNCCD),
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