Lake Chad
Cameroon / Nigeria / Niger / Chad, Africa
Surface area 1,350 km²
Average depth 1.5 m
Max. depth 11 m
Shore length 650 km
Coordinates: 13° 0' 0 N, 14° 0' 0 E	Aerial photos of lake Chad-1973-2001 [1]

 

Lake Chad (in French Lac Tchad) is a historically large, shallow lake in Africa, whose size has varied greatly over the centuries. It is economically very important, providing water to more than 20 million people living in the four countries which surround it: Chad, Cameroon, Niger, and Nigeria. It is located mainly in the far west of Chad, bordering on northeastern Nigeria. The Chari River is its largest source of water, providing over 90% of Lake Chad's water. The lake possesses many small islands and mudbanks, and its shorelines are largely composed of marshes. Because it is very shallow—only 10.5 metres (34 ft) at its deepest—its area is particularly sensitive to small changes in average depth, and it consequently also shows seasonal fluctuations in size. Lake Chad has no apparent outlet, but its waters percolate into the Soro and Bodélé depressions.

Lake Chad gave its name to the country of Chad. The name Chad is a local word meaning "large expanse of water," in other words simply "lake."

Lake Chad is believed to be a remnant of a former inland sea which has grown and shrunk with changes in climate over the past 13,000 years. At its largest, around 4000 BC, this lake is estimated to have covered an area of 400,000 km², (approx. 154,000 sq miles). Lake sediments appear to indicate dry periods, when the lake nearly dried up, around 8500 BC, 5500 BC, 2000 BC, and 100 BC."

It was one of the largest lakes in the world when first surveyed by Europeans in 1823, but it has shrunk considerably since then. An increased demand on the lake's water from the local population has likely accelerated its shrinkage over the past 40 years. A 2001 study published in the Journal of Geophysical Research blamed the lake's retreat largely on overgrazing in the area surrounding the lake, causing desertification and a decline in vegetation. According to CNN senior producer, A. Chris Gajilan, "the United Nations Environment Programme says that about half of the lake's decrease is attributable to human water use such as inefficient damming and irrigation methods. The other half of the shrinkage is due to shifting climate patterns. Anada Tiega of the Lake Chad Basin Commission blames climate change for 50 to 75 percent of the water's disappearance."

In the 1960s it had an area of more than 26,000 km², making it the fourth largest lake in Africa. By 2000 its extent had fallen to less than 1,500 km². This is due to reduced rainfall combined with greatly increased amounts of irrigation water being drawn from the lake and the rivers which feed it, the largest being the Chari/Logone system, which originates in the mountains of the Central African Republic. It seems likely that the lake will shrink further and perhaps even disappear altogether in the course of the 21st century.

The lake presently has an average depth of only 1.5 metres (4.9 ft). It nearly dried out in 1908 and again in 1984. As it retreats every summer, recessional agriculture is practised, while the Buduma people fish from canoes. [2]