SaharaThe Sahara (səˈhɑːrə, səˈhærə) is a desert on the African continent. With an area of , 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 the Arabic word for "desert" in the feminine irregular form, the singular (صحراء //ˈSaHra), plural (صَحَارَى //ˈSaHaaraa), (صَحَار), (صَحْرَاوَات), (صَحَارِي).
SahelThe Sahel (səˈhɛl; ساحل ˈsaːħil, "coast, shore") is a region in Africa. It is defined as the ecoclimatic and biogeographic realm of transition between the Sahara to the north and the Sudanian savanna to the south. Having a hot semi-arid climate, it stretches across the south-central latitudes of Northern Africa between the Atlantic Ocean and the Red Sea.
ChadChad (tʃæd ), officially the Republic of Chad, is a landlocked country at the crossroads of North and Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon to the southwest, Nigeria to the southwest (at Lake Chad), and Niger to the west. Chad has a population of 16 million, of which 1.6 million live in the capital and largest city of N'Djamena. Chad has several regions: a desert zone in the north, an arid Sahelian belt in the centre and a more fertile Sudanian Savanna zone in the south.
French colonial empireThe French Colonial Empire (Empire colonial français) comprised the overseas colonies, protectorates and mandate territories that came under French rule from the 16th century onward. A distinction is generally made between the "First French colonial empire," that existed until 1814, by which time most of it had been lost or sold, and the "Second French colonial empire," which began with the conquest of Algiers in 1830. At its apex between the two world wars, the second French colonial empire was the second-largest colonial empire in the world behind the British Empire.
African humid periodThe African humid period (AHP; also known by other names) is a climate period in Africa during the late Pleistocene and Holocene geologic epochs, when northern Africa was wetter than today. The covering of much of the Sahara desert by grasses, trees and lakes was caused by changes in the Earth’s axial tilt; changes in vegetation and dust in the Sahara which strengthened the African monsoon; and increased greenhouse gases. During the preceding Last Glacial Maximum, the Sahara contained extensive dune fields and was mostly uninhabited.
Niger RiverThe Niger River (ˈnaɪdʒər ; (le) fleuve Niger (lə) flœv niʒɛʁ) is the main river of West Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in south-eastern Guinea near the Sierra Leone border. It runs in a crescent shape through Mali, Niger, on the border with Benin and then through Nigeria, discharging through a massive delta, known as the Niger Delta (or the Oil Rivers), into the Gulf of Guinea in the Atlantic Ocean.
NigerNiger or the Niger (niːˈʒɛər,_ˈnaɪdʒər , niʒɛʁ), officially the Republic of the Niger (République du Niger; Jamhuriyar Nijar), is a landlocked country in West Africa. It is a unitary state bordered by Libya to the northeast, Chad to the east, Nigeria to the south, Benin and Burkina Faso to the southwest, Mali to the west, and Algeria to the northwest. It covers a land area of almost , making it the largest landlocked country in West Africa. Over 80% of its land area lies in the Sahara.
Trans-Saharan tradeTrans-Saharan trade requires travel across the Sahara between West, Central, Eastern and Northern Africa. While existing from prehistoric times, the peak of trade extended from the 8th century until the early 17th century. The Sahara once had a very different environment. In Libya and Algeria, from at least 7000 BC, there was pastoralism, the herding of sheep, goats, large settlements, and pottery. Cattle were introduced to the Central Sahara (Ahaggar) from 4000 to 3500 BC.
