Sahara

context: The Sahara (Arabic: الصحراء الكبرى‎, aṣ-ṣaḥrāʾ al-kubrā , 'the Greatest Desert') is the largest hot desert in the world. It is the third largest desert after Antarctica and the Arctic. Its surface area of 9,400,000 square kilometres (3,600,000 sq mi)[citation needed]—including the Libyan Desert—is comparable to the respective land areas of China or the United States. The desert comprises much of the land found within North Africa, excluding the fertile coastal region situated against the Mediterranean Sea, the Atlas Mountains of the Maghreb, and the Nile Valley of Egypt and Sudan. The Sahara 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 transitions to a coastal plain. To the south, it is delimited by the Sahel, a belt of semi-arid tropical savanna around the Niger River valley and 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. Its name is derived from the plural Arabic language word for desert (صحارى ṣaḥārā  [ˈsˤɑħɑːrɑː]).
qas: answers: text: The Sahara
question: What is the third hottest desert in the world?

answers: text: The Sahara
question: What is the third largest desert in the world?

answers: text: 9,400,000 square kilometres (3,600,000 sq mi)
question: What is the surface area of the Sahara Desert?

answers: text: Sahara
question: What is the hottest desert in the world?

context: The central part of the Sahara is hyperarid, with little to no vegetation. The northern and southern reaches of 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 part, there are many subdivisions of the great desert such as the Tanezrouft, the Ténéré, the Libyan Desert, the Eastern Desert, the Nubian Desert and others. These absolute desert regions are characterized by their extreme aridity, and some years can pass without any rainfall.
qas: answers: text: hyperarid
question: What is the central part of the Sahara Desert?

answers: text: The northern and southern reaches of the desert
question: What does the Sahara have little to none of?

answers: text: grassland and desert shrub
question: The northern and southern reaches of the desert are spare of what items?

answers: text: The northern and southern reaches of the desert
question: What does the Sahara have little of?

answers: text: years
question: How often does the Sahara go without rainfall?

context: To 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 ecoregions 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, 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.
qas: answers: text: Mediterranean Sea
question: What sea is North of the Sahara Desert?

context: To the south, the Sahara is bounded by the Sahel, a belt of dry tropical savanna with 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 is a long-term average, since precipitation varies annually).
qas: answers: text: Sahel
question: What is to the south of the Sahara?

answers: text: dry tropical
question: What kind of climate does the Sahel have?

answers: text: 150 mm
question: What is the long term precipitation average of the Sahara?

context: The Sahara is the world's largest low-latitude hot desert. The area is located in the horse latitudes under the subtropical ridge, a significant belt of semi-permanent subtropical warm-core high pressure where the air from upper levels of the troposphere tends to sink towards the ground. This steady descending airflow causes a warming and a drying effect in the upper troposphere. The sinking air prevents evaporating water from rising and, therefore, prevents the adiabatic cooling, which makes cloud formation extremely difficult to nearly impossible.
qas: answers: text: Sahara
question: What is the world's largest low latitude hot desert?

answers: text: horse latitudes
question: What ares is the Sahara located in?

answers: text: sinking air
question: What makes it difficult for clouds to form?

context: The permanent dissolution 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 a consequence, the weather tends to be sunny, dry and stable with a minimal risk 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 predominate factor that explains the hot desert climate (Köppen climate classification BWh) of this vast region. The lowering of air is the strongest and the most effective over the eastern part of the Great Desert, in the Libyan Desert which is the sunniest, the driest and the most nearly rainless place on the planet rivaling the Atacama Desert, lying in Chile and Peru.
qas: answers: text: dissolution of clouds
question: What allows unhindered light and thermal radiation?

answers: text: rainfall
question: What weather is virtually non-existent?

answers: text: eastern part of the Great Desert
question: Where is the air the strongest?

context: 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 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 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 limits to the upper troposphere during the hottest periods.
qas: answers: text: eastern
question: What section of the Sahara's cloud cover are the most   accentuated?

answers: text: hot and dry
question: What is the air mass lying above the Sahara?

answers: text: North-African desert
question: What part of the country does the air masses primarily form over?

context: 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 the atmospheric circulation itself, the desert is made even drier by his geographical configuration and location. Indeed, the extreme aridity of the Sahara can't be only explained by the subtropical high pressure. The Atlas Mountains, found in 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 the leeward side by dropping much of the humidity brought by atmospheric disturbances along the polar front which affects the surrounding Mediterranean climates.
qas: answers: text: air ascent
question: What is blocked due to local surface low pressure?

answers: text: Atlas Mountains
question: What mountain helps enhance the aridity of the desert?

answers: text: Algeria
question: Where are the Atlas Mountains located?

context: The primary source of rain in the Sahara is the equatorial low a continuous belt of low-pressure systems near the equator which bring the brief, short and irregular rainy season to the Sahel and the southern Sahara. The Sahara doesn't lack precipitation because of a lack of moisture, but due to the lack of a precipitation-generating mechanism. Rainfall in this giant desert has to overcome 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 the highest recorded worldwide.
qas: answers: text: low-pressure systems
question: What is the primary source of rain in the Sahara?

answers: text: lack of a precipitation-generating mechanism
question: What is the reason the Sahara lacks moisture?

answers: text: barriers that normally prevent the production of precipitation
question: What does the desert have to overcome?

answers: text: high temperatures year-round
question: What is the temperature like year around in the desert?

context: The sky is usually clear above the desert and the sunshine duration is extremely high everywhere in the Sahara. Most of the desert enjoys more than 3,600 h of bright sunshine annually or over 82% of the time and a wide area in the eastern part experiences in excess of 4,000 h of bright sunshine a year or over 91% of the time, and the highest values are very close to the theoretical maximum value. A value of 4,300 h or 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/(m2 year) in the Great Desert. The Sahara has a huge potential for solar energy production. The constantly high position of the sun, the extremely low relative humidity, the lack of vegetation and rainfall make the Great Desert the hottest continuously large area worldwide and certainly the hottest place on Earth during summertime in some spots. The average high temperature exceeds 38 °C (100.4 °F) - 40 °C (104 °F) during the hottest month nearly everywhere in the desert except at very high mountainous areas. The highest officially recorded average high temperature was 47 °C (116.6 °F) in a remote desert town in the Algerian Desert called Bou Bernous with an elevation of 378 meters above sea level. It's the world's highest recorded average high temperature 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 meters above sea level get slightly lower summer average highs around 46 °C (114.8 °F) during the hottest months of the year. Salah, well known in Algeria for its extreme heat, has an average high temperature of 43.8 °C (110.8 °F), 46.4 °C (115.5 °F), 45.5 (113.9 °F). Furthermore, 41.9 °C (107.4 °F) in June, July, August and September. In fact, 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 the desert experiences around 3 – 5 months when the average high strictly exceeds 40 °C (104 °F). The southern central part of the desert experiences up to 6 – 7 months when the average high temperature strictly exceeds 40 °C (104 °F) which shows the constancy and the length of the really hot season in the Sahara. 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 the hottest regions year-round. However, most of the desert has a value in excess of 25 °C (77 °F). The sand and ground temperatures are even more extreme. During daytime, the sand temperature is extremely high as 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 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 features high diurnal temperature variations between days and nights. However, it's a myth that the nights are cold after extremely hot days in the Sahara. The average diurnal temperature range is typically between 13 °C (55.4 °F) and 20 °C (68 °F). The lowest values are found along the coastal regions due to high humidity and are often even lower than 10 °C (50 °F), while the highest values are found in inland desert areas where the humidity is the lowest, mainly in the southern Sahara. Still, it's true that winter nights can be cold as it can drop to the freezing point and even below, especially in high-elevation areas.
qas: answers: text: the Great Desert
question: What is the largest hottest continuously large area   worldwide?

answers: text: 25 °C
question: What is the value temperature of most of the desert?

answers: text: 82% of the time
question: What percent of time is the sun generally over most of the   desert?

answers: text: around 2,800 kWh/(m2 year)
question: What is the annual average direct solar irradiation?

answers: text: 80 °C (176 °F)
question: During daytime how high can the temperatures reach?

context: 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 the polar front, although very attenuated by the rain shadow effects of the mountains and the annual average rainfall ranges from 100 mm (3,93 in) to 250 mm (9,84 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 the Intertropical Convergence Zone from the south and the annual average rainfall ranges from 100 mm (3,93 in) to 250 mm (9,84 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 the strongest anticyclonic weather regime and the annual average rainfall can drop to less than 1 mm (0.04 in). In fact, most of the Sahara receives less than 20 mm (0.79 in). Of the 9,000,000 km2 of desert land in the Sahara, an area of about 2,800,000 km2 (about 31% of the total area) receives an annual average rainfall amount of 10 mm (0.39 in) or less, while some 1,500,000 km2 (about 17% of the total area) receive an average of 5 mm or less. The annual average rainfall is virtually zero over a wide area of some 1,000,000 km2 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 mm per year. The rainfall 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 mm/year to more than 6,000 mm/year in the whole desert. Nowhere else on Earth has air been found as dry and evaporative as in the Sahara region. With such an evaporative power, the Sahara can only be desiccated and dried out further more and the moisture deficit is tremendous.
qas: answers: text: low pressure systems
question: What is the reason the northern fringe receives more   cloudiness and rainfall?

answers: text: less than 1 mm
question: What is the average rainfall of the Sahara?

answers: text: 9,000,000 km2 of desert land
question: How much desert land is the Sahara?

answers: text: Intertropical Convergence Zone
question: What causes the southern fringe to receive cloudiness and   rainfall?

context: The South Saharan steppe and woodlands ecoregion is a narrow band running east and west between the hyper-arid Sahara and the Sahel savannas to the south. Movements of the equatorial Intertropical Convergence Zone (ITCZ) bring summer rains during July and August which average 100 to 200 mm (3.9 to 7.9 in) but vary greatly from year to year. These rains sustain summer pastures of grasses and herbs, with dry woodlands and shrublands along seasonal watercourses. This ecoregion covers 1,101,700 km2 (425,400 mi2) in Algeria, Chad, Mali, Mauritania, and Sudan.
qas: answers: text: east and west
question: Which directions does the South Saharan run?

answers: text: July and August
question: What months do the summer rains happen?

answers: text: 100 to 200 mm
question: What is the average rainfall between the months of July and   August?

answers: text: 1,101,700 km2 (425,400 mi2)
question: How much land does the ecoregion cover?

context: The central Sahara 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 the maximum area of water and to find any surface moisture and by having small thick leaves or needles to prevent water loss by evapo-transpiration. Plant leaves may dry out totally and then recover.
qas: answers: text: five hundred species
question: What is the number of plants in the Central Sahara?

answers: text: growing lower
question: What do plants do in order to avoid water loss?

answers: text: thick stems
question: Where do plants store their water to avoid the conditions?

answers: text: long roots that travel horizontally
question: What helps plants in order to get as much water as   possible?

context: 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 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 of Egypt and Libya. They are approximately 2,000 mature individuals left in the wild.
qas: answers: text: 250
question: How many cheetahs remain in the Northwest Africa area?

answers: text: April to October
question: What months do the cheetah's avoid the sun?

answers: text: 2,000
question: How many many cheetah's are left in the wild?

context: human activities are more likely to affect 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.
qas: answers: text: human activities
question: What activities from these mammals will likely affect   habitat areas?

answers: text: irrigated water pumped
question: What underground items have lead to soil degradation?

answers: text: natural resources
question: What kind of pressure can be intense in the Sahara?

context: People lived on the edge of the desert thousands of years ago since the last ice age. 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 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. It was long believed that the region had been this way since about 1600 BCE, after shifts in the Earth's axis increased temperatures and decreased precipitation. However, this theory has recently been called into dispute, when samples taken from several 7 million year old sand deposits led scientists to reconsider the timeline for desertification.
qas: answers: text: ice age
question: When did people start living on the edge of the desert?

answers: text: Over 30,000 petroglyphs
question: How many river animals were thought to be found during   the ice age era?

answers: text: the Nile Valley
question: What area of the Sahara is full of vegetation?

answers: text: shifts in the Earth's axis
question: What is believed to have increased temperatures in the   Sahara?

context: During the Neolithic Era, before the onset of desertification, around 9500 BCE the central Sudan had been a rich environment supporting a large population ranging across what is now barren desert, like the Wadi el-Qa'ab. By the 5th millennium BCE, the people who inhabited what is now called Nubia, were full participants in the "agricultural revolution", living a settled lifestyle with domesticated plants and animals. Saharan rock art of cattle and herdsmen suggests the presence of a cattle cult like those found in Sudan and other pastoral societies in Africa today. Megaliths found at Nabta Playa are overt examples of probably the world's first known archaeoastronomy devices, predating Stonehenge by some 2,000 years. This complexity, as observed at Nabta Playa, and as expressed by different levels of authority within the society there, likely formed the basis for the structure of both the Neolithic society at Nabta and the Old Kingdom of Egypt.
qas: answers: text: Neolithic Era
question: During what era was the central Sudan rich in environment?

answers: text: cattle and herdsmen
question: What kind of rock art was found in the Sudan?

answers: text: Megaliths
question: What are examples of the first known archaeoastronomy   found in Nabta Playa?

context: By 6000 BCE predynastic Egyptians in the southwestern corner of Egypt were herding cattle and constructing large buildings. Subsistence in organized and permanent settlements in predynastic Egypt by the middle of the 6th millennium BCE centered predominantly on cereal and animal agriculture: cattle, goats, pigs and sheep. Metal objects replaced prior ones of stone. Tanning of animal skins, pottery and weaving were commonplace in this era also. There are indications of seasonal or only temporary occupation of the Al Fayyum in the 6th millennium BCE, with food activities centering on fishing, hunting and food-gathering. Stone arrowheads, knives and scrapers from the era are commonly found. Burial items included pottery, jewelry, farming and hunting equipment, and assorted foods including dried meat and fruit. Burial in desert environments appears to enhance Egyptian preservation rites, and dead were buried facing due west.
qas: answers: text: cattle
question: What were Egyptians herding in the early BCE period?

answers: text: 6000 BCE
question: By what time period were the Egyptians constructing  large buildings?

answers: text: Metal objects
question: What items replaced previously items made of stone?

answers: text: due west
question: In which direction were the dead facing when they were   buried?

context: By 3400 BCE, the Sahara was as dry as it is today, due to reduced precipitation and higher temperatures resulting from a shift in the Earth's orbit. As a result of this aridification, it became a largely impenetrable barrier to humans, with the remaining settlements mainly being concentrated around the numerous oases that dot the landscape. Little trade or commerce is known to have passed through the interior in subsequent periods, the only major exception being the Nile Valley. The Nile, however, was impassable at several cataracts, making trade and contact by boat difficult.
qas: answers: text: 3400 BCE
question: By What time period was the Sahara dry like it is today?

answers: text: reduced precipitation and higher temperatures
question: What was the main reason that the Sahara became so   dry?

answers: text: the Nile Valley
question: What area is known for having the majority of the trade?

context: By 500 BCE, Greeks arrived in the desert. Greek traders spread along the eastern coast of the desert, establishing trading colonies along the Red Sea. The Carthaginians explored the Atlantic coast of the desert, but the turbulence of the waters and the lack of markets caused a lack of presence further south than modern Morocco. Centralized states thus surrounded the desert on the north and east; it remained outside the control of these states. Raids from the nomadic Berber people of the desert were a constant concern of those living on the edge of the desert.
qas: answers: text: Red Sea
question: Where did the Greeks established their trading colonies?

answers: text: the Atlantic coast
question: Which coast did the Carthaginians explore for trade?

answers: text: nomadic Berber
question: Who would raid the desert leaving the people in constant   fear?

context: An urban civilization, the Garamantes, arose around 500 BCE in the heart of the Sahara, in a valley that is now called the Wadi al-Ajal in Fezzan, Libya. The Garamantes achieved this development by digging tunnels far into the mountains flanking the valley to tap fossil water and bring it to their fields. The Garamantes grew populous and strong, conquering their neighbors and capturing many slaves (which were put to work extending the tunnels). The ancient Greeks and the Romans knew of the Garamantes and regarded them as uncivilized nomads. However, they traded with the Garamantes, and a Roman bath has been found in the Garamantes capital of Garama. Archaeologists have found eight major towns and many other important settlements in the Garamantes territory. The Garamantes civilization eventually collapsed after they had depleted available water in the aquifers and could no longer sustain the effort to extend the tunnels further into the mountains.
qas: answers: text: 500 BCE
question: What time period did the Garamantes arrive in?

answers: text: digging tunnels
question: What did the Garamantes do in order to bring water to   their crops?

answers: text: eight major towns
question: How many towns are believed to be found by   Archaeologists?

answers: text: depleted available water
question: What was the reason for the collapse of the Garamantes   civilization?

context: The Byzantine Empire ruled the northern shores of the Sahara from the 5th to the 7th centuries. After the Muslim conquest of Arabia (Arabian peninsula) the Muslim conquest of North Africa began in the mid-7th to early 8th centuries, Islamic influence expanded rapidly on the Sahara. By the end of 641 all of Egypt was in Muslim hands. The trade across the desert intensified. A significant slave trade crossed the desert. It has been estimated that from the 10th to 19th centuries some 6,000 to 7,000 slaves were transported north each year.
qas: answers: text: Byzantine Empire
question: What group of people ruled the northern shoes of the   Sahara?

answers: text: mid-7th to early 8th centuries
question: What time period did the Muslim conquest of North Africa   take place?

answers: text: 6,000 to 7,000 slaves
question: What is the estimated number of slaves that were   transported each year?

context: In the 16th century the northern fringe of the Sahara, such as coastal regencies in present-day Algeria and Tunisia, as well as some parts of present-day Libya, together with the semi-autonomous kingdom of Egypt, were occupied by the Ottoman Empire. From 1517 Egypt was a valued part of the Ottoman Empire, ownership of which provided the Ottomans with control over the Nile Valley, the east Mediterranean and North Africa. The benefit of the Ottoman Empire was the freedom of movement for citizens and goods. Trade exploited the Ottoman land routes to handle the spices, gold and silk from the East, manufactures from Europe, and the slave and gold traffic from Africa. Arabic continued as the local language and Islamic culture was much reinforced. The Sahel and southern Sahara regions were home to several independent states or to roaming Tuareg clans.
qas: answers: text: Egypt
question: During the 1500 who was a valued part of the Ottoman   Empire?

answers: text: freedom of movement for citizens and goods
question: What did the Ottoman Empire provide to its people?

answers: text: Arabic
question: What was the local language during this time in Egypt?

context: European colonialism in the Sahara began in the 19th century. France conquered the regency of Algiers from the Ottomans in 1830, and French rule spread south from Algeria and eastwards from Senegal into the upper Niger to include present-day Algeria, Chad, Mali then French Sudan including Timbuktu, Mauritania, Morocco (1912), Niger, and Tunisia (1881). By the beginning of the 20th century, the trans-Saharan trade had clearly declined because goods were moved through more modern and efficient means, such as airplanes, rather than across the desert.
qas: answers: text: 19th century
question: What time period did the colonialism of the Sahara begin?

answers: text: France
question: What country conquered the Algiers from the Ottomans in   1830?

answers: text: 20th century
question: During what time were good moved through more modern   means?

context: Arabic dialects are the most widely spoken languages in the Sahara. The live in the Red Sea Hills of southeastern Egypt and eastern Sudan. Arabic, Berber and its variants now regrouped under the term Amazigh (which includes the Guanche language spoken by the original Berber inhabitants of the Canary Islands) and Beja languages are part of the Afro-Asiatic or Hamito-Semitic family.[citation needed] Unlike neighboring West Africa and the central governments of the states that comprise the Sahara, the French language bears little relevance to inter-personal discourse and commerce within the region, its people retaining staunch ethnic and political affiliations with Tuareg and Berber leaders and culture. The legacy of the French colonial era administration is primarily manifested in the territorial reorganization enacted by the Third and Fourth republics, which engendered artificial political divisions within a hitherto isolated and porous region. Diplomacy with local clients was primarily conducted in Arabic, which was the traditional language of bureaucratic affairs. Mediation of disputes and inter-agency communication was served by interpreters contracted by the French government, who, according to Keenan, "documented a space of intercultural mediation," contributing much to preserving indigenous cultural identities in the region.
qas: answers: text: Arabic
question: What is the most common dialect spoken in the Sahara?

answers: text: French
question: What language is mainly spoken in West Africa?

answers: text: Arabic
question: What was the traditional language of Bureaucratic affairs?