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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." [10]
A satellite image of the Sahara, the world's largest hot desert and third largest desert after Antarctica and the Arctic. Desert greening is the process of afforestation or revegetation of deserts for ecological restoration (biodiversity), sustainable farming and forestry, but also for reclamation of natural water systems and other ecological systems that support life.
The cultivation of semi-arid regions encourages erosion of soil and is one of the causes of increased desertification. Desert farming is possible with the aid of irrigation, and the Imperial Valley in California provides an example of how previously barren land can be made productive by the import of water from an outside source.
A 10.3 million km2 area, or 34.2% of the continent's surface, is at risk of desertification. If the deserts (Sahara and Kalahari) are taken into account, the affected and potentially affected area is roughly 16.5 million km2 or 54.6% of all of Africa. 5.7 percent of the continent's surface is made up of very severe regions, 16.2 percent by ...
Within 43 years, Kenya's forest coverage decreased from about 10% to 1.7%. Deforestation in Madagascar has also led to desertification, soil loss, and water source degradation, resulting in the country's inability to provide necessary resources for its growing population. [8] In the last five years, Nigeria lost nearly half of its primary forests.
Historic desertification is the study of the desert-forming process from a historic perspective. It was presumed in the past that the main causes of desertification lay in overuse of the land resulting in impoverishment of the soil, reduced vegetation cover, increased risk of drought and the resulting wind erosion. However recent projects to ...
Egyptian geometry refers to geometry as it was developed and used in Ancient Egypt. Their geometry was a necessary outgrowth of surveying to preserve the layout and ownership of farmland, which was flooded annually by the Nile river. [1] We only have a limited number of problems from ancient Egypt that concern geometry.
A Cartesian coordinate system in two dimensions (also called a rectangular coordinate system or an orthogonal coordinate system [8]) is defined by an ordered pair of perpendicular lines (axes), a single unit of length for both axes, and an orientation for each axis. The point where the axes meet is taken as the origin for both, thus turning ...