Karoo
The Karoo (/kəˈruː/ kə-ROO; from the South Khoekhoe !Orakobab or Khoemana word ǃ’Aukarob "Hardveld"[2][3]) is a semi-desert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its extent is also not precisely defined. The Karoo is partly defined by its topography, geology and climate, and above all, its low rainfall, arid air, cloudless skies, and extremes of heat and cold.[4][5] The Karoo also hosted a well-preserved ecosystem hundreds of million years ago which is now represented by many fossils.[6]
The ǃ’Aukarob formed an almost impenetrable barrier to the interior from Cape Town, and the early adventurers, explorers, hunters, and travelers on the way to the Highveld unanimously denounced it as a frightening place of great heat, great frosts, great floods, and great droughts.[7] Today, it is still a place of great heat and frosts, and an annual rainfall of between 50 and 250 mm, though on some of the mountains it can be 250 to 500 mm higher than on the plains.[4] However, underground water is found throughout the Karoo, which can be tapped by boreholes, making permanent settlements and sheep farming possible.[4][5]
The xerophytic vegetation consists of aloes, mesembryanthemums, crassulas, euphorbias, stapelias, and desert ephemerals, spaced 50 cm or more apart,[4][8] and becoming very sparse going northwards into Bushmanland and, from there, into the Kalahari Desert. The driest region of the Karoo, however, is its southwestern corner, between the Great Escarpment and the Cederberg-Skurweberg mountain ranges, called the Tankwa Karoo, which receives only 75 mm of rain annually.[4] The eastern and north-eastern Karoo are often covered by large patches of grassland. The typical Karoo vegetation used to support large game, sometimes in vast herds.[7][9]
Today, sheep thrive on the xerophytes, though each sheep requires about 4 ha of grazing to sustain itself.[4]
The Karoo is divided into the Great Karoo and the Little Karoo. The Little Karoo is delimited in the south by the Outeniqua–Langeberg Mountains that run east-west parallel to the coast, and in the north by the Swartberg Mountain Range that also runs east-west. The Great Karoo lies to the north the Swartberg.
The only sharp and definite boundary of the Great Karoo is formed by the most inland ranges of Cape Fold Mountains to the south and south-west. The extent of the Karoo to the north is vague, fading gradually and almost imperceptibly into the increasingly arid Bushmanland towards the north-west. To the north and north-east, it fades into the savannah and grasslands of Griqualand West and the Highveld.[1][11] The boundary to the east grades into the grasslands of the Eastern Midlands.[12]The Great Karoo is itself divided by the Great Escarpment into the Upper Karoo (generally above 1200–1500 m) and the Lower Karoo on the plains below at 700–800 m. A great many local names, each denoting different subregions of the Great Karoo, exist, some more widely, or more generally, known than others. In the Lower Karoo, going from west to east, they are the Tankwa Karoo, the Moordenaarskaroo, the Koup, the Vlakte, and the Camdeboo Plains. The Hantam, Kareeberge, Roggeveld, and uweveldare the better known subregions of the Upper Karoo, though most of it is simply known as the Upper Karoo, especially in the north.[1]
