Geography of Mauritania

Mauritania, a country in the western region of the continent of Africa, is generally flat, its 1,030,700 square kilometres forming vast, arid plains broken by occasional ridges and clifflike outcroppings. It borders the North Atlantic Ocean, between Senegal and Western Sahara, Mali and Algeria. It is considered part of both the Sahel and the Maghreb. A series of scarps face southwest, longitudinally bisecting these plains in the center of the country. The scarps also separate a series of sandstone plateaus, the highest of which is the Adrar Plateau, reaching an elevation of 500 metres. Spring-fed oases lie at the foot of some of the scarps. Isolated peaks, often rich in minerals, rise above the plateaus; the smaller peaks are called guelbs and the larger ones kedias. The concentric Guelb er Richat is a prominent feature of the north-central region. Kediet ej Jill, near the city of Zouîrât, has an elevation of 1,000 metres and is the highest peak.

Approximately three-fourths of Mauritania is desert or semidesert. As a result of extended, severe drought, the desert has been expanding since the mid-1960s. The plateaus gradually descend toward the northeast to the barren El Djouf, or "Empty Quarter," a vast region of large sand dunes that merges into the Sahara Desert. To the west, between the ocean and the plateaus, are alternating areas of clayey plains (regs) and sand dunes (ergs), some of which shift from place to place, gradually moved by high winds. The dunes generally increase in size and mobility toward the north.

Belts of natural vegetation, corresponding to the rainfall pattern, extend from east to west and range from traces of tropical forest along the Sénégal River to brush and savanna in the southeast. Only sandy desert is found in the centre and north of the country.

The climate is characterized by extremes in temperature and by meager and irregular rainfall. Annual temperature variations are small, although diurnal variations can be extreme. The harmattan, a hot, dry, and often dust-laden wind, blows from the Sahara throughout the long dry season and is the prevailing wind, except along the narrow coastal strip, which is influenced by oceanic trade winds. Most rain falls during the short rainy season (hivernage), from July to September, and average annual precipitation varies from 500 to 600 millimetres (19.7 to 23.6 in) in the far south to less than 100 millimetres (3.9 in) in the northern two-thirds of the country.

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