Ghardaïa ( Arabic : غرداية , Tumzabt : Taɣerdayt ) is the capital city of Ghardaïa Province , Algeria . The commune of Ghardaïa has a population of 93,423 according to the 2008 census, up from 87,599 in 1998, with an annual growth rate of 0.7%.
164-564: It is located in northern-central Algeria in the Sahara and lies along the left bank of the Wadi Mzab. The M'zab in the Ghardaïa Province was made a World Heritage Site in 1982, as a cultural property evaluated under the criteria II (for its settlement affecting urban planning even to the present century), III (for its Ibadi cultural values), and V (a settlement culture which has prevailed to
328-562: A cemetery and a mosque. The ksar was created in 476/1085 by two tribes : the Aoulad Ammi-Aïssa and the Aoulad Ba-Slimane. Each tribe contained different fractions, a specific area and a cemetery . Ghardaïa is the richest city of the M'Zab Vallée. It already had a dynamic commercial and craft activity. On the social aspect, it is the only Ksar, along with Melika, that housed not only Ibadites Berbers, but also Malekits Arabs and
492-585: A Jewish community until the Algerian Independence. To build the Ksar, the founders of Ghardaïa, a small group of people, under a Cheikh, chose a hill 200m south of the M'Zab Oued for defensive purposes. Farther west, they created a palm grove for subsistence farming. The Ksar of Ghardaïa, as it is today, did not appear in one time. According to the public agency in charge of protecting the M'Zab Heritage, Ghardaïa has seen four phases of evolution until 1882, when it
656-503: A bed of flowers. The three are assumed to have died within 24 hours of each other, but as their skeletons hold no apparent trauma (they did not die violently) and they have been buried so elaborately – unlikely if they had died of a plague – the cause of their deaths is a mystery. Sahara Desert The Sahara ( / s ə ˈ h ɑːr ə / , / s ə ˈ h ær ə / ) is a desert spanning across North Africa . With an area of 9,200,000 square kilometres (3,600,000 sq mi), it
820-549: A cave (ghār) in the area before it blossomed into a town inhabited by Ibadi Muslims who came to escape persecution from the Fatimid Caliphate in the north. The M'Zab valley, in limestone plateau , was inscribed under the UNESCO Heritage List, is a unique conglomeration of five cities confined in area of 75 km² situated 600 km to the south of Algiers , the capital of Algeria. The original architecture of
984-426: A consequence, the weather tends to be sunny, dry and stable with a minimal chance of rainfall. Subsiding, diverging, dry air masses associated with subtropical high-pressure systems are extremely unfavorable for the development of convectional showers. The subtropical ridge is the predominant factor that explains the hot desert climate ( Köppen climate classification BWh ) of this vast region. The descending airflow
1148-426: A consequence, the weather tends to be sunny, dry and stable with a minimal chance of rainfall. Subsiding, diverging, dry air masses associated with subtropical high-pressure systems are extremely unfavorable for the development of convectional showers. The subtropical ridge is the predominant factor that explains the hot desert climate ( Köppen climate classification BWh ) of this vast region. The descending airflow
1312-515: A healthy adult. The Saharan silver ant is unique in that due to the extreme high temperatures of their habitat, and the threat of predators, the ants are active outside their nest for only about ten minutes per day. Dromedary camels and goats are the domesticated animals most commonly found in the Sahara. Because of its qualities of endurance and speed, the dromedary is the favourite animal used by nomads . Human activities are more likely to affect
1476-466: A healthy adult. The Saharan silver ant is unique in that due to the extreme high temperatures of their habitat, and the threat of predators, the ants are active outside their nest for only about ten minutes per day. Dromedary camels and goats are the domesticated animals most commonly found in the Sahara. Because of its qualities of endurance and speed, the dromedary is the favourite animal used by nomads . Human activities are more likely to affect
1640-477: A number of suburbs, towns and villages in addition to Ghardaïa. Suburb settlements include Mélika , Béni Isguen , Bounoura (Has Bunur) and El Atteuf (Tadjnint), all of which lie to the southeast of Ghardaïa city and the ancient ksar of Metlili-Chaamba or Metlili which lies 42 km (26 mi) to the southwest. Outside of the Mzab valley, Berriane (Has Ibergane) and El Guerrara (Iguerraren) are towns of note,
1804-451: A pyramid-style mosque and an arcaded square. Distinctive white, pink, and red houses, made of sand, clay and gypsum, rise in terraces and arcades. In her 1963 book, La Force des choses , the French existentialist philosopher Simone de Beauvoir described Ghardaïa as "a Cubist painting beautifully constructed". The name of Ghardaïa has its origins in a female saint named Daïa who lived in
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#17328687495281968-558: A summer rainy season that extends across Africa from east to west. The southern limit of the Sahara is indicated botanically by the southern limit of Cornulaca monacantha (a drought-tolerant member of the Chenopodiaceae ), or northern limit of Cenchrus biflorus , a grass typical of the Sahel. According to climatic criteria, the southern limit of the Sahara corresponds to the 150 mm (5.9 in) isohyet of annual precipitation (this
2132-454: A summer rainy season that extends across Africa from east to west. The southern limit of the Sahara is indicated botanically by the southern limit of Cornulaca monacantha (a drought-tolerant member of the Chenopodiaceae ), or northern limit of Cenchrus biflorus , a grass typical of the Sahel. According to climatic criteria, the southern limit of the Sahara corresponds to the 150 mm (5.9 in) isohyet of annual precipitation (this
2296-542: A surface feature of Earth, with near-current technology. The Sahara is mainly rocky hamada (stone plateaus); ergs (sand seas – large areas covered with sand dunes ) form only a minor part, contrary to common misconception , but many of the sand dunes are over 180 metres (590 ft) high. Wind or rare rainfall shape the desert features: sand dunes, dune fields, sand seas, stone plateaus, gravel plains ( reg ), dry valleys ( wadi ), dry lakes ( oued ), and salt flats ( shatt or chott ). Unusual landforms include
2460-542: A surface feature of Earth, with near-current technology. The Sahara is mainly rocky hamada (stone plateaus); ergs (sand seas – large areas covered with sand dunes ) form only a minor part, contrary to common misconception , but many of the sand dunes are over 180 metres (590 ft) high. Wind or rare rainfall shape the desert features: sand dunes, dune fields, sand seas, stone plateaus, gravel plains ( reg ), dry valleys ( wadi ), dry lakes ( oued ), and salt flats ( shatt or chott ). Unusual landforms include
2624-473: Is 87.4%, and is 93.2% among males and 81.5% among females. The town is served by Noumérat – Moufdi Zakaria Airport (or simply Ghardaïa airport ). There is also a bus station. The airport is named after Algerian writer Moufdi Zakaria , who was born in Ghardaïa. The commune of Ghardaïa is composed of nine localities: Sahara The Sahara ( / s ə ˈ h ɑːr ə / , / s ə ˈ h ær ə / )
2788-527: Is a desert spanning across North Africa . With an area of 9,200,000 square kilometres (3,600,000 sq mi), it is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic . The name "Sahara" is derived from Arabic : صَحَارَى , romanized : ṣaḥārā /sˤaħaːraː/ , a broken plural form of ṣaḥrā' ( صَحْرَاء /sˤaħraːʔ/ ), meaning "desert". The desert covers much of North Africa , excluding
2952-639: Is a long-term average, since precipitation varies annually). Important cities located in the Sahara include Nouakchott , the capital of Mauritania; Tamanrasset , Ouargla , Béchar , Hassi Messaoud , Ghardaïa , and El Oued in Algeria; Timbuktu in Mali; Agadez in Niger; Ghat in Libya; and Faya-Largeau in Chad. The Sahara is the world's largest hot desert . It is located in
3116-399: Is a long-term average, since precipitation varies annually). Important cities located in the Sahara include Nouakchott , the capital of Mauritania; Tamanrasset , Ouargla , Béchar , Hassi Messaoud , Ghardaïa , and El Oued in Algeria; Timbuktu in Mali; Agadez in Niger; Ghat in Libya; and Faya-Largeau in Chad. The Sahara is the world's largest hot desert . It is located in
3280-422: Is a north African gazelle that can also go for a long time without water. Other notable gazelles include the rhim gazelle and dama gazelle . The Saharan cheetah ( northwest African cheetah ) lives in Algeria, Togo , Niger, Mali, Benin , and Burkina Faso . There remain fewer than 250 mature cheetahs, which are very cautious, fleeing any human presence. The cheetah avoids the sun from April to October, seeking
3444-422: Is a north African gazelle that can also go for a long time without water. Other notable gazelles include the rhim gazelle and dama gazelle . The Saharan cheetah ( northwest African cheetah ) lives in Algeria, Togo , Niger, Mali, Benin , and Burkina Faso . There remain fewer than 250 mature cheetahs, which are very cautious, fleeing any human presence. The cheetah avoids the sun from April to October, seeking
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#17328687495283608-609: Is a prehistoric industry, or domain, that existed between 10,000 and 8,000 years ago in the Sahara, during the Neolithic Subpluvial . Human remains from this culture were found in 2000 at a site known as Gobero , located in Niger in the Ténéré Desert . The site is known as the largest and earliest grave of Stone Age people in the Sahara. The Kiffians were skilled hunters . Bones of many large savannah animals that were discovered in
3772-445: Is a prehistoric industry, or domain, that existed between 10,000 and 8,000 years ago in the Sahara, during the Neolithic Subpluvial . Human remains from this culture were found in 2000 at a site known as Gobero , located in Niger in the Ténéré Desert . The site is known as the largest and earliest grave of Stone Age people in the Sahara. The Kiffians were skilled hunters . Bones of many large savannah animals that were discovered in
3936-512: Is accessed in a number of ways through a complex irrigation system that distributes water from many wells. Well drilling extends to a depth ranging from 350 ft (110 m) to 500 ft (150 m), drawing the water from the Albian fossil groundwater continental infill whose reserves are estimated at 1.5 trillion m. Ghardaïa has a hot desert climate ( Köppen climate classification BWh ), with extremely hot summers and mild winters. The region
4100-494: Is also well known for its Weaving, Dinanderie D'art, basketry, pottery and carpet weaving (tapestry). The rugs of the area are so popular that every year the "National Day Of Rugs" is held in March. The Mozabites of Ghardaïa have their distinct identity of traditional costume of saroual loubia (baggy trousers) and chéchia (headgear). Every spring, the commune of Metlili-Chaamba, 31.3 km (19.4 mi) from Ghardaïa, celebrates
4264-460: Is associated with high rates of wind-blown mineral dust, and these dust levels are found as expected in marine cores from the north tropical Atlantic. But around 12,500 BCE the amount of dust in the cores in the Bølling / Allerød phase suddenly plummets and shows a period of much wetter conditions in the Sahara, indicating a Dansgaard-Oeschger (DO) event (a sudden warming followed by a slower cooling of
4428-411: Is associated with high rates of wind-blown mineral dust, and these dust levels are found as expected in marine cores from the north tropical Atlantic. But around 12,500 BCE the amount of dust in the cores in the Bølling / Allerød phase suddenly plummets and shows a period of much wetter conditions in the Sahara, indicating a Dansgaard-Oeschger (DO) event (a sudden warming followed by a slower cooling of
4592-403: Is estimated to include five hundred species of plants, which is extremely low considering the huge extent of the area. Plants such as acacia trees, palms, succulents, spiny shrubs, and grasses have adapted to the arid conditions, by growing lower to avoid water loss by strong winds, by storing water in their thick stems to use it in dry periods, by having long roots that travel horizontally to reach
4756-403: Is estimated to include five hundred species of plants, which is extremely low considering the huge extent of the area. Plants such as acacia trees, palms, succulents, spiny shrubs, and grasses have adapted to the arid conditions, by growing lower to avoid water loss by strong winds, by storing water in their thick stems to use it in dry periods, by having long roots that travel horizontally to reach
4920-433: Is marked by large temperature differences between day and night, and summer and winter ranging from lows of 5 °C (41 °F) to highs of 46 °C (114.8 °F). The prevailing winds of summer are extremely hot, extremely dry and strong, while winter winds are warm and dry. Sandstorms generally occur from March to May. In October 2008, Ghardaïa was severely affected by flooding due to heavy rain. The unique layout of
5084-407: Is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic . The name "Sahara" is derived from Arabic : صَحَارَى , romanized : ṣaḥārā /sˤaħaːraː/ , a broken plural form of ṣaḥrā' ( صَحْرَاء /sˤaħraːʔ/ ), meaning "desert". The desert covers much of North Africa , excluding
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5248-406: Is the manufacture of rugs and cloths. Metlili-Chaamba is known for its "Deglet Nour" dates and its camel hair products. One important aspect of the social life and economic values of the people of the region is that begging and theft are non-existent in the community. The society is close-knit, and all aspects of economy and social customs are dictated by the community. The residents have preserved
5412-643: Is the strongest and the most effective over the eastern part of the Great Desert, in the Libyan Desert: this is the sunniest, driest and the most nearly "rainless" place on the planet, rivaling the Atacama Desert , lying in Chile and Peru . The rainfall inhibition and the dissipation of cloud cover are most accentuated over the eastern section of the Sahara rather than the western. The prevailing air mass lying above
5576-429: Is the strongest and the most effective over the eastern part of the Great Desert, in the Libyan Desert: this is the sunniest, driest and the most nearly "rainless" place on the planet, rivaling the Atacama Desert , lying in Chile and Peru . The rainfall inhibition and the dissipation of cloud cover are most accentuated over the eastern section of the Sahara rather than the western. The prevailing air mass lying above
5740-422: Is very unreliable and erratic in the Sahara as it may vary considerably year by year. In full contrast to the negligible annual rainfall amounts, the annual rates of potential evaporation are extraordinarily high, roughly ranging from 2,500 millimetres (100 in) per year to more than 6,000 millimetres (240 in) per year in the whole desert. Nowhere else on Earth has air been found as dry and evaporative as in
5904-422: Is very unreliable and erratic in the Sahara as it may vary considerably year by year. In full contrast to the negligible annual rainfall amounts, the annual rates of potential evaporation are extraordinarily high, roughly ranging from 2,500 millimetres (100 in) per year to more than 6,000 millimetres (240 in) per year in the whole desert. Nowhere else on Earth has air been found as dry and evaporative as in
6068-535: The Adrar of Mauritania and a value of 75 °C (167 °F) has been measured in Borkou , northern Chad. Due to lack of cloud cover and very low humidity, the desert usually has high diurnal temperature variations between days and nights. However, it is a myth that the nights are especially cold after extremely hot days in the Sahara. On average, nighttime temperatures tend to be 13–20 °C (23–36 °F) cooler than in
6232-440: The Adrar of Mauritania and a value of 75 °C (167 °F) has been measured in Borkou , northern Chad. Due to lack of cloud cover and very low humidity, the desert usually has high diurnal temperature variations between days and nights. However, it is a myth that the nights are especially cold after extremely hot days in the Sahara. On average, nighttime temperatures tend to be 13–20 °C (23–36 °F) cooler than in
6396-481: The Algerian Desert called Bou Bernous , at an elevation of 378 metres (1,240 ft) above sea level, and only Death Valley, California rivals it. Other hot spots in Algeria such as Adrar , Timimoun , In Salah , Ouallene , Aoulef , Reggane with an elevation between 200 and 400 metres (660 and 1,310 ft) above sea level get slightly lower summer average highs, around 46 °C (114.8 °F) during
6560-424: The Algerian Desert called Bou Bernous , at an elevation of 378 metres (1,240 ft) above sea level, and only Death Valley, California rivals it. Other hot spots in Algeria such as Adrar , Timimoun , In Salah , Ouallene , Aoulef , Reggane with an elevation between 200 and 400 metres (660 and 1,310 ft) above sea level get slightly lower summer average highs, around 46 °C (114.8 °F) during
6724-742: The Late Pleistocene Iberomaurusians , early Holocene Capsians , and mid-Holocene Mechta groups, whereas the Tenerian crania are more like those of Mediterranean groups. Graves show that the Tenerians observed spiritual traditions, as they were buried with artifacts such as jewelry made of hippo tusks and clay pots. The most interesting find is a triple burial, dated to 5300 years ago, of an adult female and two children, estimated through their teeth as being five and eight years old, hugging each other. Pollen residue indicates they were buried on
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6888-565: The Late Pleistocene Iberomaurusians , early Holocene Capsians , and mid-Holocene Mechta groups, whereas the Tenerian crania are more like those of Mediterranean groups. Graves show that the Tenerians observed spiritual traditions, as they were buried with artifacts such as jewelry made of hippo tusks and clay pots. The most interesting find is a triple burial, dated to 5300 years ago, of an adult female and two children, estimated through their teeth as being five and eight years old, hugging each other. Pollen residue indicates they were buried on
7052-726: The Niger River valley and the Sudan region of sub-Saharan Africa . The Sahara can be divided into several regions, including the western Sahara, the central Ahaggar Mountains , the Tibesti Mountains , the Aïr Mountains , the Ténéré desert, and the Libyan Desert . For several hundred thousand years, the Sahara has alternated between desert and savanna grassland in a 20,000-year cycle caused by
7216-410: The Niger River valley and the Sudan region of sub-Saharan Africa . The Sahara can be divided into several regions, including the western Sahara, the central Ahaggar Mountains , the Tibesti Mountains , the Aïr Mountains , the Ténéré desert, and the Libyan Desert . For several hundred thousand years, the Sahara has alternated between desert and savanna grassland in a 20,000-year cycle caused by
7380-668: The Richat Structure in Mauritania. Several deeply dissected mountains, many volcanic, rise from the desert, including the Aïr Mountains , Ahaggar Mountains , Saharan Atlas , Tibesti Mountains , Adrar des Iforas , and the Red Sea Hills . The highest peak in the Sahara is Emi Koussi , a shield volcano in the Tibesti range of northern Chad. The central Sahara is hyperarid , with sparse vegetation. The northern and southern reaches of
7544-453: The Richat Structure in Mauritania. Several deeply dissected mountains, many volcanic, rise from the desert, including the Aïr Mountains , Ahaggar Mountains , Saharan Atlas , Tibesti Mountains , Adrar des Iforas , and the Red Sea Hills . The highest peak in the Sahara is Emi Koussi , a shield volcano in the Tibesti range of northern Chad. The central Sahara is hyperarid , with sparse vegetation. The northern and southern reaches of
7708-474: The horse latitudes under the subtropical ridge , a significant belt of semi-permanent subtropical warm-core high pressure where the air from the upper troposphere usually descends, warming and drying the lower troposphere and preventing cloud formation. The permanent absence of clouds allows unhindered light and thermal radiation. The stability of the atmosphere above the desert prevents any convective overturning, thus making rainfall virtually non-existent. As
7872-474: The horse latitudes under the subtropical ridge , a significant belt of semi-permanent subtropical warm-core high pressure where the air from the upper troposphere usually descends, warming and drying the lower troposphere and preventing cloud formation. The permanent absence of clouds allows unhindered light and thermal radiation. The stability of the atmosphere above the desert prevents any convective overturning, thus making rainfall virtually non-existent. As
8036-504: The precession of Earth's axis (about 26,000 years) as it rotates around the Sun, which changes the location of the North African monsoon . The Sahara covers large parts of Algeria , Chad , Egypt , Libya , Mali , Mauritania , Niger , Western Sahara and Sudan , and parts of southern Morocco and Tunisia . It covers 9 million square kilometres (3,500,000 sq mi), 31% of
8200-403: The precession of Earth's axis (about 26,000 years) as it rotates around the Sun, which changes the location of the North African monsoon . The Sahara covers large parts of Algeria , Chad , Egypt , Libya , Mali , Mauritania , Niger , Western Sahara and Sudan , and parts of southern Morocco and Tunisia . It covers 9 million square kilometres (3,500,000 sq mi), 31% of
8364-543: The "Day mehr" when people from all over the country attend and participate in a camel race. In March and April, a carpet festival provides an opportunity for celebration, competition, as well as sales. Ghardaïa is the traditional heart of the M'zab valley and home of the Ibadi religious sect in Algeria. They do not subscribe to the doctrines of Sunnism and Shi'ism . They practice a different way of praying, worshipping of God, and designing mosques compared to Malikis , who form
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#17328687495288528-499: The African continent. If all areas with a mean annual precipitation of less than 250 mm (9.8 in) were included, the Sahara would be 11 million square kilometres (4,200,000 sq mi). It is one of three distinct physiographic provinces of the African massive physiographic division . The Sahara is so large and bright that, in theory, it could be detected from other stars as
8692-400: The African continent. If all areas with a mean annual precipitation of less than 250 mm (9.8 in) were included, the Sahara would be 11 million square kilometres (4,200,000 sq mi). It is one of three distinct physiographic provinces of the African massive physiographic division . The Sahara is so large and bright that, in theory, it could be detected from other stars as
8856-417: The African humid period. At its largest extent, sometime before 5000 BCE, Lake Mega-Chad was the largest of four Saharan paleolakes, and is estimated to have covered an area of 350,000 km . The Sahara pump theory describes this cycle. During periods of a wet or " Green Sahara ", the Sahara becomes a savanna grassland and various flora and fauna become more common. Following inter-pluvial arid periods,
9020-417: The African humid period. At its largest extent, sometime before 5000 BCE, Lake Mega-Chad was the largest of four Saharan paleolakes, and is estimated to have covered an area of 350,000 km . The Sahara pump theory describes this cycle. During periods of a wet or " Green Sahara ", the Sahara becomes a savanna grassland and various flora and fauna become more common. Following inter-pluvial arid periods,
9184-401: The Ghardaïa village is dictated by the rocky terrain of the region. Apart from the mosques and the housing pattern layout, with the mosque at the top of the hill, and the houses laid in labyrinthine alleyways, there is also a large market centre. The houses in particular are oriented in such a way that admits sunlight into every dwelling, as this is strongly believed to be healthy: "Inhabitants of
9348-412: The Great Desert the hottest large region in the world, and the hottest place on Earth during summer in some spots. The average high temperature exceeds 38 to 40 °C (100.4 to 104.0 °F) during the hottest month nearly everywhere in the desert except at very high altitudes. The world's highest officially recorded average daily high temperature was 47 °C (116.6 °F) in a remote desert town in
9512-412: The Great Desert the hottest large region in the world, and the hottest place on Earth during summer in some spots. The average high temperature exceeds 38 to 40 °C (100.4 to 104.0 °F) during the hottest month nearly everywhere in the desert except at very high altitudes. The world's highest officially recorded average daily high temperature was 47 °C (116.6 °F) in a remote desert town in
9676-474: The Intertropical Convergence Zone from the south and the annual average rainfall ranges from 100 millimetres (4 in) to 250 millimetres (10 in). For example, Timbuktu, Mali and Agadez , Niger are found in this zone. The vast central hyper-arid core of the desert is virtually never affected by northerly or southerly atmospheric disturbances and permanently remains under the influence of
9840-401: The Intertropical Convergence Zone from the south and the annual average rainfall ranges from 100 millimetres (4 in) to 250 millimetres (10 in). For example, Timbuktu, Mali and Agadez , Niger are found in this zone. The vast central hyper-arid core of the desert is virtually never affected by northerly or southerly atmospheric disturbances and permanently remains under the influence of
10004-513: The Kiffian culture do not exist after 8,000 years ago, as the Sahara went through a dry period for the next thousand years. After this time, the Tenerian culture colonized the area. Gobero was discovered in 2000 during an archaeological expedition led by Paul Sereno , which sought dinosaur remains. Two distinct prehistoric cultures were discovered at the site: the early Holocene Kiffian culture, and
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#173286874952810168-413: The Kiffian culture do not exist after 8,000 years ago, as the Sahara went through a dry period for the next thousand years. After this time, the Tenerian culture colonized the area. Gobero was discovered in 2000 during an archaeological expedition led by Paul Sereno , which sought dinosaur remains. Two distinct prehistoric cultures were discovered at the site: the early Holocene Kiffian culture, and
10332-408: The M'Zab valley. They settled in five fortified villages located on rocky outcrops, known locally as “Kosars”, although they could have lived in one larger village encompassing all the five. The habitation was planned with meticulous details to precise layouts defined by set principles of community living within a defensive environment. Ghardaïa's foundation has been dated to 1048 or 1053. Each village
10496-455: The Sahara (birds in particular) such as African silverbill and black-faced firefinch , among others. There are also small desert crocodiles in Mauritania and the Ennedi Plateau of Chad. The deathstalker scorpion can be 10 cm (3.9 in) long. Its venom contains large amounts of agitoxin and scyllatoxin and is very dangerous; however, a sting from this scorpion rarely kills
10660-399: The Sahara (birds in particular) such as African silverbill and black-faced firefinch , among others. There are also small desert crocodiles in Mauritania and the Ennedi Plateau of Chad. The deathstalker scorpion can be 10 cm (3.9 in) long. Its venom contains large amounts of agitoxin and scyllatoxin and is very dangerous; however, a sting from this scorpion rarely kills
10824-518: The Sahara area then reverts to desert conditions and the flora and fauna are forced to retreat northwards to the Atlas Mountains , southwards into West Africa , or eastwards into the Nile Valley . This separates populations of some of the species in areas with different climates , forcing them to adapt , possibly giving rise to allopatric speciation . It is also proposed that humans accelerated
10988-408: The Sahara area then reverts to desert conditions and the flora and fauna are forced to retreat northwards to the Atlas Mountains , southwards into West Africa , or eastwards into the Nile Valley . This separates populations of some of the species in areas with different climates , forcing them to adapt , possibly giving rise to allopatric speciation . It is also proposed that humans accelerated
11152-514: The Sahara is strongly influenced by the North Atlantic Oscillation (NAO), with warmer winter temperatures during negative NAO events and cooler winters with more frosts when the NAO is positive. This is because the weaker clockwise flow around the eastern side of the subtropical anticyclone during negative NAO winters, although too dry to produce more than negligible precipitation, does reduce
11316-400: The Sahara is strongly influenced by the North Atlantic Oscillation (NAO), with warmer winter temperatures during negative NAO events and cooler winters with more frosts when the NAO is positive. This is because the weaker clockwise flow around the eastern side of the subtropical anticyclone during negative NAO winters, although too dry to produce more than negligible precipitation, does reduce
11480-497: The Sahara is the continental tropical (cT) air mass, which is hot and dry. Hot, dry air masses primarily form over the North-African desert from the heating of the vast continental land area, and it affects the whole desert during most of the year. Because of this extreme heating process, a thermal low is usually noticed near the surface, and is the strongest and the most developed during the summertime. The Sahara High represents
11644-441: The Sahara is the continental tropical (cT) air mass, which is hot and dry. Hot, dry air masses primarily form over the North-African desert from the heating of the vast continental land area, and it affects the whole desert during most of the year. Because of this extreme heating process, a thermal low is usually noticed near the surface, and is the strongest and the most developed during the summertime. The Sahara High represents
11808-616: The Sahara region. However, at least two instances of snowfall have been recorded in Sahara, in February 1979 and December 2016, both in the town of Ain Sefra . One theory for the formation of the Sahara is that the monsoon in Northern Africa was weakened because of glaciation during the Quaternary period, starting two or three million years ago. Another theory is that the monsoon was weakened when
11972-407: The Sahara region. However, at least two instances of snowfall have been recorded in Sahara, in February 1979 and December 2016, both in the town of Ain Sefra . One theory for the formation of the Sahara is that the monsoon in Northern Africa was weakened because of glaciation during the Quaternary period, starting two or three million years ago. Another theory is that the monsoon was weakened when
12136-698: The Tassili n'Ajjer in southeast Algeria. Fossils of dinosaurs , including Afrovenator , Jobaria and Ouranosaurus , have also been found here. The modern Sahara, though, is not lush in vegetation, except in the Nile Valley, at a few oases , and in the northern highlands, where Mediterranean plants such as the olive tree are found to grow. Shifts in Earth's axis increased temperatures and decreased precipitation, which caused an abrupt beginning of North Africa desertification about 5,400 years ago. The Kiffian culture
12300-548: The Tassili n'Ajjer in southeast Algeria. Fossils of dinosaurs , including Afrovenator , Jobaria and Ouranosaurus , have also been found here. The modern Sahara, though, is not lush in vegetation, except in the Nile Valley, at a few oases , and in the northern highlands, where Mediterranean plants such as the olive tree are found to grow. Shifts in Earth's axis increased temperatures and decreased precipitation, which caused an abrupt beginning of North Africa desertification about 5,400 years ago. The Kiffian culture
12464-461: The Wilaya of Ghardaïa also draws anthropologists, architects, researchers and historians to explore its rich cultural, anthropological and architectural uniqueness. An interesting aspect of community welfare is the fact that they follow the rules of governance diligently, and also contribute to the maintenance and care of the community. Mozabites in the light of their rigid approach in negotiations, dominate
12628-576: The amount of rainfall received – the Northern (Mediterranean), Central and Southern Zones. There are two transitional zones – the Mediterranean-Sahara transition and the Sahel transition zone. The Saharan flora comprises around 2800 species of vascular plants . Approximately a quarter of these are endemic . About half of these species are common to the flora of the Arabian deserts. The central Sahara
12792-412: The amount of rainfall received – the Northern (Mediterranean), Central and Southern Zones. There are two transitional zones – the Mediterranean-Sahara transition and the Sahel transition zone. The Saharan flora comprises around 2800 species of vascular plants . Approximately a quarter of these are endemic . About half of these species are common to the flora of the Arabian deserts. The central Sahara
12956-536: The ancient Tethys Sea dried up during the Tortonian period around 7 million years ago. The climate of the Sahara has undergone enormous variations between wet and dry over the last few hundred thousand years, believed to be caused by long-term changes in the North African climate cycle that alters the path of the North African Monsoon – usually southward. The cycle is caused by a 41,000-year cycle in which
13120-422: The ancient Tethys Sea dried up during the Tortonian period around 7 million years ago. The climate of the Sahara has undergone enormous variations between wet and dry over the last few hundred thousand years, believed to be caused by long-term changes in the North African climate cycle that alters the path of the North African Monsoon – usually southward. The cycle is caused by a 41,000-year cycle in which
13284-421: The atmospheric circulation itself, the desert is made even drier by its geographical configuration and location. Indeed, the extreme aridity of the Sahara is not only explained by the subtropical high pressure: the Atlas Mountains of Algeria, Morocco and Tunisia also help to enhance the aridity of the northern part of the desert. These major mountain ranges act as a barrier, causing a strong rain shadow effect on
13448-421: The atmospheric circulation itself, the desert is made even drier by its geographical configuration and location. Indeed, the extreme aridity of the Sahara is not only explained by the subtropical high pressure: the Atlas Mountains of Algeria, Morocco and Tunisia also help to enhance the aridity of the northern part of the desert. These major mountain ranges act as a barrier, causing a strong rain shadow effect on
13612-489: The cathedral is meanwhile secularized; the diocese is still exempt). Until Algerian independence, Ghardaïa was home to a significant Jewish community, of which many were deaf. The deaf Jews of Ghardaïa developed their own village sign language , which they took with them when the community left for France and Israel. The language is considered moribund. 6.5% of the population has a tertiary education, and another 18.2% has completed secondary education. The overall literacy rate
13776-600: The climate). The moister Saharan conditions had begun about 12,500 BCE, with the extension of the ITCZ northward in the northern hemisphere summer, bringing moist wet conditions and a savanna climate to the Sahara, which (apart from a short dry spell associated with the Younger Dryas ) peaked during the Holocene thermal maximum climatic phase at 4000 BCE when mid-latitude temperatures seem to have been between 2 and 3 degrees warmer than in
13940-448: The climate). The moister Saharan conditions had begun about 12,500 BCE, with the extension of the ITCZ northward in the northern hemisphere summer, bringing moist wet conditions and a savanna climate to the Sahara, which (apart from a short dry spell associated with the Younger Dryas ) peaked during the Holocene thermal maximum climatic phase at 4000 BCE when mid-latitude temperatures seem to have been between 2 and 3 degrees warmer than in
14104-474: The daytime. The smallest variations are found along the coastal regions due to high humidity and are often even lower than a 10 °C (18 °F) difference, while the largest variations are found in inland desert areas where the humidity is the lowest, mainly in the southern Sahara. Still, it is true that winter nights can be cold, as it can drop to the freezing point and even below, especially in high-elevation areas. The frequency of subfreezing winter nights in
14268-474: The daytime. The smallest variations are found along the coastal regions due to high humidity and are often even lower than a 10 °C (18 °F) difference, while the largest variations are found in inland desert areas where the humidity is the lowest, mainly in the southern Sahara. Still, it is true that winter nights can be cold, as it can drop to the freezing point and even below, especially in high-elevation areas. The frequency of subfreezing winter nights in
14432-469: The desert experiences around three to five months when the average high strictly exceeds 40 °C (104 °F); while in the southern central part of the desert, there are up to six or seven months when the average high temperature strictly exceeds 40 °C (104 °F). Some examples of this are Bilma , Niger and Faya-Largeau, Chad. The annual average daily temperature exceeds 20 °C (68 °F) everywhere and can approach 30 °C (86 °F) in
14596-469: The desert experiences around three to five months when the average high strictly exceeds 40 °C (104 °F); while in the southern central part of the desert, there are up to six or seven months when the average high temperature strictly exceeds 40 °C (104 °F). Some examples of this are Bilma , Niger and Faya-Largeau, Chad. The annual average daily temperature exceeds 20 °C (68 °F) everywhere and can approach 30 °C (86 °F) in
14760-516: The desert, along with the highlands, have areas of sparse grassland and desert shrub , with trees and taller shrubs in wadis , where moisture collects. In the central, hyperarid region, there are many subdivisions of the great desert: Tanezrouft , the Ténéré , the Libyan Desert , the Eastern Desert , the Nubian Desert and others. These extremely arid areas often receive no rain for years. To
14924-405: The desert, along with the highlands, have areas of sparse grassland and desert shrub , with trees and taller shrubs in wadis , where moisture collects. In the central, hyperarid region, there are many subdivisions of the great desert: Tanezrouft , the Ténéré , the Libyan Desert , the Eastern Desert , the Nubian Desert and others. These extremely arid areas often receive no rain for years. To
15088-526: The drying-out period from 6000 to 2500 BCE by pastoralists overgrazing available grassland. The growth of speleothems (which requires rainwater) was detected in Hol-Zakh, Ashalim , Even-Sid, Ma'ale-ha-Meyshar, Ktora Cracks, Nagev Tzavoa Cave, and elsewhere, and has allowed tracking of prehistoric rainfall. The Red Sea coastal route was extremely arid before 140 and after 115 kya (thousands of years ago). Slightly wetter conditions appear at 90–87 kya, but it still
15252-475: The drying-out period from 6000 to 2500 BCE by pastoralists overgrazing available grassland. The growth of speleothems (which requires rainwater) was detected in Hol-Zakh, Ashalim , Even-Sid, Ma'ale-ha-Meyshar, Ktora Cracks, Nagev Tzavoa Cave, and elsewhere, and has allowed tracking of prehistoric rainfall. The Red Sea coastal route was extremely arid before 140 and after 115 kya (thousands of years ago). Slightly wetter conditions appear at 90–87 kya, but it still
15416-646: The eastern continental extension of the Azores High , centered over the North Atlantic Ocean . The subsidence of the Sahara High nearly reaches the ground during the coolest part of the year, while it is confined to the upper troposphere during the hottest periods. The effects of local surface low pressure are extremely limited because upper-level subsidence still continues to block any form of air ascent. Also, to be protected against rain-bearing weather systems by
15580-477: The eastern continental extension of the Azores High , centered over the North Atlantic Ocean . The subsidence of the Sahara High nearly reaches the ground during the coolest part of the year, while it is confined to the upper troposphere during the hottest periods. The effects of local surface low pressure are extremely limited because upper-level subsidence still continues to block any form of air ascent. Also, to be protected against rain-bearing weather systems by
15744-600: The edge of the desert thousands of years ago, since the end of the last glacial period . In the Central Sahara, engraved and painted rock art were created perhaps as early as 10,000 years ago, spanning the Bubaline Period , Kel Essuf Period , Round Head Period , Pastoral Period , Caballine Period , and Cameline Period . The Sahara was then a much wetter place than it is today. Over 30,000 petroglyphs of river animals such as crocodiles survive, with half found in
15908-486: The edge of the desert thousands of years ago, since the end of the last glacial period . In the Central Sahara, engraved and painted rock art were created perhaps as early as 10,000 years ago, spanning the Bubaline Period , Kel Essuf Period , Round Head Period , Pastoral Period , Caballine Period , and Cameline Period . The Sahara was then a much wetter place than it is today. Over 30,000 petroglyphs of river animals such as crocodiles survive, with half found in
16072-782: The fertile region on the Mediterranean Sea coast, the Atlas Mountains of the Maghreb , and the Nile Valley in Egypt and the Sudan . It stretches from the Red Sea in the east and the Mediterranean in the north to the Atlantic Ocean in the west, where the landscape gradually changes from desert to coastal plains. To the south it is bounded by the Sahel , a belt of semi-arid tropical savanna around
16236-419: The fertile region on the Mediterranean Sea coast, the Atlas Mountains of the Maghreb , and the Nile Valley in Egypt and the Sudan . It stretches from the Red Sea in the east and the Mediterranean in the north to the Atlantic Ocean in the west, where the landscape gradually changes from desert to coastal plains. To the south it is bounded by the Sahel , a belt of semi-arid tropical savanna around
16400-517: The financial sector, particularly in banking and wholesale sectors. They also have their own mosque, cemetery, recreation and sporting activities. They have a patriarchal system of social inheritance. Another unique feature among the Mozabites is that starting from birth a “Mozabite is looked after by the community for education, work, marriage, and the building of a home. Touiza (groups of volunteers) are organised for building houses.” The Wilaya of Ghardaïa
16564-529: The first 45 km (28 mi) to the north, and the second 110 km (68 mi) to the northeast. Ghardaïa's ancient water distribution system was devised by the Mozabites, as a response to the ephemeral flows of its oueds (rivers). Realising the preciousness of this natural resource, the Mozabites developed a unique hydraulic system of tunnels to harvest rainwater and divert it to the oases. They have an equitable water distribution to all gardens and also maintain good flood protection measures. The water supply
16728-476: The flow of dry, cold air from higher latitudes of Eurasia into the Sahara significantly. The average annual rainfall ranges from very low in the northern and southern fringes of the desert to nearly non-existent over the central and the eastern part. The thin northern fringe of the desert receives more winter cloudiness and rainfall due to the arrival of low pressure systems over the Mediterranean Sea along
16892-416: The flow of dry, cold air from higher latitudes of Eurasia into the Sahara significantly. The average annual rainfall ranges from very low in the northern and southern fringes of the desert to nearly non-existent over the central and the eastern part. The thin northern fringe of the desert receives more winter cloudiness and rainfall due to the arrival of low pressure systems over the Mediterranean Sea along
17056-699: The habitat in areas of permanent water (oases) or where water comes close to the surface. Here, the local pressure on natural resources can be intense. The remaining populations of large mammals have been greatly reduced by hunting for food and recreation. In recent years development projects have started in the deserts of Algeria and Tunisia using irrigated water pumped from underground aquifers. These schemes often lead to soil degradation and salinization . Researchers from Hacettepe University have reported that Saharan soil may have bio-available iron and also some essential macro and micro nutrient elements suitable for use as fertilizer for growing wheat. People lived on
17220-699: The habitat in areas of permanent water (oases) or where water comes close to the surface. Here, the local pressure on natural resources can be intense. The remaining populations of large mammals have been greatly reduced by hunting for food and recreation. In recent years development projects have started in the deserts of Algeria and Tunisia using irrigated water pumped from underground aquifers. These schemes often lead to soil degradation and salinization . Researchers from Hacettepe University have reported that Saharan soil may have bio-available iron and also some essential macro and micro nutrient elements suitable for use as fertilizer for growing wheat. People lived on
17384-405: The highest recorded worldwide. The sky is usually clear above the desert, and the sunshine duration is extremely high everywhere in the Sahara. Most of the desert has more than 3,600 hours of bright sunshine per year (over 82% of daylight hours), and a wide area in the eastern part has over 4,000 hours of bright sunshine per year (over 91% of daylight hours). The highest values are very close to
17548-405: The highest recorded worldwide. The sky is usually clear above the desert, and the sunshine duration is extremely high everywhere in the Sahara. Most of the desert has more than 3,600 hours of bright sunshine per year (over 82% of daylight hours), and a wide area in the eastern part has over 4,000 hours of bright sunshine per year (over 91% of daylight hours). The highest values are very close to
17712-543: The hottest months of the year. Salah, well known in Algeria for its extreme heat, has average high temperatures of 43.8 °C (110.8 °F), 46.4 °C (115.5 °F), 45.5 °C (113.9 °F) and 41.9 °C (107.4 °F) in June, July, August and September respectively. There are even hotter spots in the Sahara, but they are located in extremely remote areas, especially in the Azalai , lying in northern Mali. The major part of
17876-448: The hottest months of the year. Salah, well known in Algeria for its extreme heat, has average high temperatures of 43.8 °C (110.8 °F), 46.4 °C (115.5 °F), 45.5 °C (113.9 °F) and 41.9 °C (107.4 °F) in June, July, August and September respectively. There are even hotter spots in the Sahara, but they are located in extremely remote areas, especially in the Azalai , lying in northern Mali. The major part of
18040-485: The hottest regions year-round. However, most of the desert has a value in excess of 25 °C (77 °F). Sand and ground temperatures are even more extreme. During daytime, the sand temperature is extremely high: it can easily reach 80 °C (176 °F) or more. A sand temperature of 83.5 °C (182.3 °F) has been recorded in Port Sudan . Ground temperatures of 72 °C (161.6 °F) have been recorded in
18204-433: The hottest regions year-round. However, most of the desert has a value in excess of 25 °C (77 °F). Sand and ground temperatures are even more extreme. During daytime, the sand temperature is extremely high: it can easily reach 80 °C (176 °F) or more. A sand temperature of 83.5 °C (182.3 °F) has been recorded in Port Sudan . Ground temperatures of 72 °C (161.6 °F) have been recorded in
18368-419: The house where sun comes in will never see a doctor". Chimneys are also set in such a way that they do not encroach upon the comfort of neighbours. Ghardaïa is a major centre of date production, with nearly 60,000 palm trees producing dates. The wood of dead palms is used to make house roofs; live trees are not killed, as they are considered living beings that sustain the inhabitants. Another important industry
18532-413: The houses built around the mosque in concentric circles and surrounded by a high walls (extending up to the ramparts). The buildings together gave the feel of a fortress to each village. The mosque also provided for storage of grains and arms for defence. However, during the summer season the inhabitants migrated to a "citadel" outside the fortified villages, in an informal setting of artificial palm grove,
18696-406: The last glacial period , the Sahara was much larger than it is today, extending south beyond its current boundaries. The end of the glacial period brought more rain to the Sahara, from about 8000 BCE to 6000 BCE, perhaps because of low pressure areas over the collapsing ice sheets to the north. Once the ice sheets were gone, the northern Sahara dried out. In the southern Sahara, the drying trend
18860-406: The last glacial period , the Sahara was much larger than it is today, extending south beyond its current boundaries. The end of the glacial period brought more rain to the Sahara, from about 8000 BCE to 6000 BCE, perhaps because of low pressure areas over the collapsing ice sheets to the north. Once the ice sheets were gone, the northern Sahara dried out. In the southern Sahara, the drying trend
19024-458: The late nineteenth century, The hypothesis was later formally proposed and tested by the meteorologist John Kutzbach in 1981. Kutzbach's ideas about the impacts of insolation on global monsoonal patterns have become widely accepted today as the underlying driver of long-term monsoonal cycles. Kutzbach never formally named his hypothesis and as such it is referred to here as the " Orbital Monsoon Hypothesis " as suggested by Ruddiman in 2001. During
19188-458: The late nineteenth century, The hypothesis was later formally proposed and tested by the meteorologist John Kutzbach in 1981. Kutzbach's ideas about the impacts of insolation on global monsoonal patterns have become widely accepted today as the underlying driver of long-term monsoonal cycles. Kutzbach never formally named his hypothesis and as such it is referred to here as the " Orbital Monsoon Hypothesis " as suggested by Ruddiman in 2001. During
19352-518: The leeward side by dropping much of the humidity brought by atmospheric disturbances along the polar front which affects the surrounding Mediterranean climates. The primary source of rain in the Sahara is the Intertropical Convergence Zone , a continuous belt of low-pressure systems near the equator which bring the brief, short and irregular rainy season to the Sahel and southern Sahara. Rainfall in this giant desert has to overcome
19516-446: The leeward side by dropping much of the humidity brought by atmospheric disturbances along the polar front which affects the surrounding Mediterranean climates. The primary source of rain in the Sahara is the Intertropical Convergence Zone , a continuous belt of low-pressure systems near the equator which bring the brief, short and irregular rainy season to the Sahel and southern Sahara. Rainfall in this giant desert has to overcome
19680-410: The majority of Algerians. The wastage of water, and more generally any gift of land, is considered a sin. The Ghardaïa Mosque, built in the 10th century, is of Moorish architecture style. Its tower, simple and elegant, includes a large portal at the top of the shaft, the design of which provides for ventilation flow. The White Fathers , a Roman Catholic missionary society, live in a hermitage near
19844-419: The maximum area of water and to find any surface moisture, and by having small thick leaves or needles to prevent water loss by evapotranspiration . Plant leaves may dry out totally and then recover. Several species of fox live in the Sahara including: the fennec fox , pale fox and Rüppell's fox . The addax , a large white antelope , can go nearly a year in the desert without drinking. The dorcas gazelle
20008-419: The maximum area of water and to find any surface moisture, and by having small thick leaves or needles to prevent water loss by evapotranspiration . Plant leaves may dry out totally and then recover. Several species of fox live in the Sahara including: the fennec fox , pale fox and Rüppell's fox . The addax , a large white antelope , can go nearly a year in the desert without drinking. The dorcas gazelle
20172-437: The middle Holocene Tenerian culture . The post-Kiffian desiccation lasted until around 4600 BCE, when the earliest artefacts associated with the Tenerians have been dated to. Some 200 skeletons have been discovered at Gobero. The Tenerians were considerably shorter in height and less robust than the earlier Kiffians. Craniometric analysis also indicates that they were osteologically distinct. The Kiffian skulls are akin to those of
20336-437: The middle Holocene Tenerian culture . The post-Kiffian desiccation lasted until around 4600 BCE, when the earliest artefacts associated with the Tenerians have been dated to. Some 200 skeletons have been discovered at Gobero. The Tenerians were considerably shorter in height and less robust than the earlier Kiffians. Craniometric analysis also indicates that they were osteologically distinct. The Kiffian skulls are akin to those of
20500-563: The north, the Sahara skirts the Mediterranean Sea in Egypt and portions of Libya, but in Cyrenaica and the Maghreb , the Sahara borders the Mediterranean forest, woodland, and scrub eco-regions of northern Africa, all of which have a Mediterranean climate characterized by hot summers and cool and rainy winters. According to the botanical criteria of Frank White and geographer Robert Capot-Rey,
20664-409: The north, the Sahara skirts the Mediterranean Sea in Egypt and portions of Libya, but in Cyrenaica and the Maghreb , the Sahara borders the Mediterranean forest, woodland, and scrub eco-regions of northern Africa, all of which have a Mediterranean climate characterized by hot summers and cool and rainy winters. According to the botanical criteria of Frank White and geographer Robert Capot-Rey,
20828-472: The northern limit of the Sahara corresponds to the northern limit of date palm cultivation and the southern limit of the range of esparto , a grass typical of the Mediterranean climate portion of the Maghreb and Iberia . The northern limit also corresponds to the 100 mm (3.9 in) isohyet of annual precipitation. To the south, the Sahara is bounded by the Sahel, a belt of dry tropical savanna with
20992-422: The northern limit of the Sahara corresponds to the northern limit of date palm cultivation and the southern limit of the range of esparto , a grass typical of the Mediterranean climate portion of the Maghreb and Iberia . The northern limit also corresponds to the 100 mm (3.9 in) isohyet of annual precipitation. To the south, the Sahara is bounded by the Sahel, a belt of dry tropical savanna with
21156-678: The old city, and have a collection of books on the Sahara. The pro-cathedral still testifies to the time when it was the seat from 1901 successively of the Apostolic Prefecture of Ghardaïa ; the province was renamed as the Apostolic Prefecture of Ghardaïa in the Sahara, in 1948 promoted to the Apostolic Vicariate of Ghardaïa in the Sahara , and then in 1955 was promoted to the Roman Catholic Diocese of Laghouat (where
21320-455: The opposite is true, with decreased annual precipitation and less vegetation resulting in a phase of the Sahara climate cycle known as the "desert Sahara". The idea that changes in insolation (solar heating) caused by long-term changes in Earth's orbit are a controlling factor for the long-term variations in the strength of monsoon patterns across the globe was first suggested by Rudolf Spitaler in
21484-407: The opposite is true, with decreased annual precipitation and less vegetation resulting in a phase of the Sahara climate cycle known as the "desert Sahara". The idea that changes in insolation (solar heating) caused by long-term changes in Earth's orbit are a controlling factor for the long-term variations in the strength of monsoon patterns across the globe was first suggested by Rudolf Spitaler in
21648-419: The original medieval architecture remarkably well; the valley to which Ghardaïa belongs is part of an official World Heritage Site . The Medabian quarter lies to the northwest. The military compound and hospital are located in the southern area. The city is called "the pearl of the oasis", and is one of the most important tourist regions in southern Algeria due to its ancient cultural heritage. Apart from tourism,
21812-419: The physical and atmospheric barriers that normally prevent the production of precipitation. The harsh climate of the Sahara is characterized by: extremely low, unreliable, highly erratic rainfall; extremely high sunshine duration values; high temperatures year-round; negligible rates of relative humidity ; a significant diurnal temperature variation ; and extremely high levels of potential evaporation which are
21976-419: The physical and atmospheric barriers that normally prevent the production of precipitation. The harsh climate of the Sahara is characterized by: extremely low, unreliable, highly erratic rainfall; extremely high sunshine duration values; high temperatures year-round; negligible rates of relative humidity ; a significant diurnal temperature variation ; and extremely high levels of potential evaporation which are
22140-401: The polar front, although very attenuated by the rain shadow effects of the mountains and the annual average rainfall ranges from 100 millimetres (4 in) to 250 millimetres (10 in). For example, Biskra , Algeria, and Ouarzazate , Morocco, are found in this zone. The southern fringe of the desert along the border with the Sahel receives summer cloudiness and rainfall due to the arrival of
22304-401: The polar front, although very attenuated by the rain shadow effects of the mountains and the annual average rainfall ranges from 100 millimetres (4 in) to 250 millimetres (10 in). For example, Biskra , Algeria, and Ouarzazate , Morocco, are found in this zone. The southern fringe of the desert along the border with the Sahel receives summer cloudiness and rainfall due to the arrival of
22468-574: The present century). Ghardaïa is part of a pentapolis , a hilltop city amongst four others, built almost a thousand years ago in the M’Zab valley. It was founded by the Mozabites , an Ibadi sect of the Berber Muslims. It is a major centre of date production and the manufacture of rugs and cloths. Divided into three walled sectors, it is a fortified town. At the centre is the historical Mʾzabite area, with
22632-518: The recent past. Analysis of Nile River deposited sediments in the delta also shows this period had a higher proportion of sediments coming from the Blue Nile , suggesting higher rainfall also in the Ethiopian Highlands . This was caused principally by a stronger monsoonal circulation throughout the sub-tropical regions, affecting India, Arabia and the Sahara. Lake Victoria only recently became
22796-406: The recent past. Analysis of Nile River deposited sediments in the delta also shows this period had a higher proportion of sediments coming from the Blue Nile , suggesting higher rainfall also in the Ethiopian Highlands . This was caused principally by a stronger monsoonal circulation throughout the sub-tropical regions, affecting India, Arabia and the Sahara. Lake Victoria only recently became
22960-587: The same area suggest that they lived on the shores of a lake that was present during the Holocene Wet Phase, a period when the Sahara was verdant and wet. The Kiffian people were tall, standing over six feet in height. Craniometric analysis indicates that this early Holocene population was closely related to the Late Pleistocene Iberomaurusians and early Holocene Capsians of the Maghreb, as well as mid-Holocene Mechta groups. Traces of
23124-451: The same area suggest that they lived on the shores of a lake that was present during the Holocene Wet Phase, a period when the Sahara was verdant and wet. The Kiffian people were tall, standing over six feet in height. Craniometric analysis indicates that this early Holocene population was closely related to the Late Pleistocene Iberomaurusians and early Holocene Capsians of the Maghreb, as well as mid-Holocene Mechta groups. Traces of
23288-459: The scale of the Nile floods between 2700 and 2100 BCE. The Sahara comprises several distinct ecoregions . With their variations in temperature, rainfall, elevation, and soil, these regions harbor distinct communities of plants and animals. The flora of the Sahara is highly diversified based on the bio-geographical characteristics of this vast desert. Floristically , the Sahara has three zones based on
23452-412: The scale of the Nile floods between 2700 and 2100 BCE. The Sahara comprises several distinct ecoregions . With their variations in temperature, rainfall, elevation, and soil, these regions harbor distinct communities of plants and animals. The flora of the Sahara is highly diversified based on the bio-geographical characteristics of this vast desert. Floristically , the Sahara has three zones based on
23616-465: The semi desert valley is dated to early 11th century. It is ascribed to the Ibadis , with their cultural identity originally traced to the Maghreb ; they had their capital at Tahert as an Ibadi Kingdom. They were forced to leave Tahert consequent to a devastating fire in 909 (it is reported that destruction was caused by the founder of the (Shi'ite) Fatimid Dynasty ). They first moved to Sedrata and finally to
23780-521: The shelter of shrubs such as balanites and acacias. They are unusually pale. The other cheetah subspecies ( northeast African cheetah ) lives in Chad, Sudan and the eastern region of Niger. However, it is currently extinct in the wild in Egypt and Libya. There are approximately 2000 mature individuals left in the wild. Other animals include the monitor lizards , hyrax , sand vipers , and small populations of African wild dog , in perhaps only 14 countries and red-necked ostrich . Other animals exist in
23944-521: The shelter of shrubs such as balanites and acacias. They are unusually pale. The other cheetah subspecies ( northeast African cheetah ) lives in Chad, Sudan and the eastern region of Niger. However, it is currently extinct in the wild in Egypt and Libya. There are approximately 2000 mature individuals left in the wild. Other animals include the monitor lizards , hyrax , sand vipers , and small populations of African wild dog , in perhaps only 14 countries and red-necked ostrich . Other animals exist in
24108-573: The source of the White Nile and dried out almost completely around 15 kya. The sudden subsequent movement of the ITCZ southwards with a Heinrich event (a sudden cooling followed by a slower warming), linked to changes with the El Niño-Southern Oscillation cycle, led to a rapid drying out of the Saharan and Arabian regions, which quickly became desert. This is linked to a marked decline in
24272-401: The source of the White Nile and dried out almost completely around 15 kya. The sudden subsequent movement of the ITCZ southwards with a Heinrich event (a sudden cooling followed by a slower warming), linked to changes with the El Niño-Southern Oscillation cycle, led to a rapid drying out of the Saharan and Arabian regions, which quickly became desert. This is linked to a marked decline in
24436-561: The strongest anticyclonic weather regime, and the annual average rainfall can drop to less than 1 millimetre (0.04 in). In fact, most of the Sahara receives less than 20 millimetres (0.8 in). Of the 9,000,000 square kilometres (3,500,000 sq mi) of desert land in the Sahara, an area of about 2,800,000 square kilometres (1,100,000 sq mi) (about 31% of the total area) receives an annual average rainfall amount of 10 millimetres (0.4 in) or less, while some 1,500,000 square kilometres (580,000 sq mi) (about 17% of
24600-561: The strongest anticyclonic weather regime, and the annual average rainfall can drop to less than 1 millimetre (0.04 in). In fact, most of the Sahara receives less than 20 millimetres (0.8 in). Of the 9,000,000 square kilometres (3,500,000 sq mi) of desert land in the Sahara, an area of about 2,800,000 square kilometres (1,100,000 sq mi) (about 31% of the total area) receives an annual average rainfall amount of 10 millimetres (0.4 in) or less, while some 1,500,000 square kilometres (580,000 sq mi) (about 17% of
24764-549: The theoretical maximum value. A value of 4300 hours (98%) of the time would be recorded in Upper Egypt ( Aswan , Luxor ) and in the Nubian Desert ( Wadi Halfa ). The annual average direct solar irradiation is around 2,800 kWh/(m year) in the Great Desert. The Sahara has a huge potential for solar energy production. The high position of the Sun, the extremely low relative humidity, and the lack of vegetation and rainfall make
24928-440: The theoretical maximum value. A value of 4300 hours (98%) of the time would be recorded in Upper Egypt ( Aswan , Luxor ) and in the Nubian Desert ( Wadi Halfa ). The annual average direct solar irradiation is around 2,800 kWh/(m year) in the Great Desert. The Sahara has a huge potential for solar energy production. The high position of the Sun, the extremely low relative humidity, and the lack of vegetation and rainfall make
25092-465: The tilt of the earth changes between 22° and 24.5°. At present, it is in a dry period, but it is expected that the Sahara will become green again in 15,000 years. When the North African monsoon is at its strongest, annual precipitation and subsequent vegetation in the Sahara region increase, resulting in conditions commonly referred to as the " green Sahara ". For a relatively weak North African monsoon,
25256-409: The tilt of the earth changes between 22° and 24.5°. At present, it is in a dry period, but it is expected that the Sahara will become green again in 15,000 years. When the North African monsoon is at its strongest, annual precipitation and subsequent vegetation in the Sahara region increase, resulting in conditions commonly referred to as the " green Sahara ". For a relatively weak North African monsoon,
25420-478: The total area) receives an average of 5 millimetres (0.2 in) or less. The annual average rainfall is virtually zero over a wide area of some 1,000,000 square kilometres (390,000 sq mi) in the eastern Sahara comprising deserts of: Libya, Egypt and Sudan ( Tazirbu , Kufra , Dakhla , Kharga , Farafra , Siwa , Asyut , Sohag , Luxor, Aswan, Abu Simbel , Wadi Halfa) where the long-term mean approximates 0.5 millimetres (0.02 in) per year. Rainfall
25584-478: The total area) receives an average of 5 millimetres (0.2 in) or less. The annual average rainfall is virtually zero over a wide area of some 1,000,000 square kilometres (390,000 sq mi) in the eastern Sahara comprising deserts of: Libya, Egypt and Sudan ( Tazirbu , Kufra , Dakhla , Kharga , Farafra , Siwa , Asyut , Sohag , Luxor, Aswan, Abu Simbel , Wadi Halfa) where the long-term mean approximates 0.5 millimetres (0.02 in) per year. Rainfall
25748-642: Was annexed by the French army. The city is located within the Sahara Desert in northern-central Algeria. Ghardaïa Province is divided into 13 communes or municipalities, which includes the Ghardaïa municipality. It is bordered by Ouargla and El Bayadh Wilayas. It is nestled in the M'zab valley, lying on the left bank of the Wadi Mzab , which is commonly dry throughout the year. The commune of Ghardaïa now covers an area of 590 km (230 sq mi) and includes
25912-403: Was initially counteracted by the monsoon , which brought rain further north than it does today. By around 4200 BCE, however, the monsoon retreated south to approximately where it is today, leading to the gradual desertification of the Sahara. The Sahara is now as dry as it was about 13,000 years ago. Lake Chad is the remnant of a former inland sea, paleolake Mega-Chad, which existed during
26076-403: Was initially counteracted by the monsoon , which brought rain further north than it does today. By around 4200 BCE, however, the monsoon retreated south to approximately where it is today, leading to the gradual desertification of the Sahara. The Sahara is now as dry as it was about 13,000 years ago. Lake Chad is the remnant of a former inland sea, paleolake Mega-Chad, which existed during
26240-461: Was just one tenth the rainfall around 125 kya. In the southern Negev Desert speleothems did not grow between 185 and 140 kya ( MIS 6), 110–90 (MIS 5.4–5.2), nor after 85 kya nor during most of the interglacial period (MIS 5.1), the glacial period and Holocene . This suggests that the southern Negev was arid-to-hyper-arid in these periods. During the Last Glacial Maximum (LGM) the Sahara
26404-399: Was just one tenth the rainfall around 125 kya. In the southern Negev Desert speleothems did not grow between 185 and 140 kya ( MIS 6), 110–90 (MIS 5.4–5.2), nor after 85 kya nor during most of the interglacial period (MIS 5.1), the glacial period and Holocene . This suggests that the southern Negev was arid-to-hyper-arid in these periods. During the Last Glacial Maximum (LGM) the Sahara
26568-556: Was more extensive than it is now with the extent of the tropical forests being greatly reduced, and the lower temperatures reduced the strength of the Hadley Cell . This is a climate cell which causes rising tropical air of the Inter-Tropical Convergence Zone (ITCZ) to bring rain to the tropics, while dry descending air, at about 20 degrees north , flows back to the equator and brings desert conditions to this region. It
26732-430: Was more extensive than it is now with the extent of the tropical forests being greatly reduced, and the lower temperatures reduced the strength of the Hadley Cell . This is a climate cell which causes rising tropical air of the Inter-Tropical Convergence Zone (ITCZ) to bring rain to the tropics, while dry descending air, at about 20 degrees north , flows back to the equator and brings desert conditions to this region. It
26896-446: Was planned in a diverse topography comprising a small island, a ridge, a hilltop, a peak and a recess. The villages were fortified in such a manner that they were inaccessible to the nomadic groups. The five villages set up with identical planning concepts were Ghardaïa, Melika, Beni Isguen, Bou Noura and El Atteuf. The identical “miniature citadels”, as they are termed, each had their own mosque with minaret functioning as watch towers, and
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