Fluctuations in Water Levels of Lake Chad, Chad – December 17th, 201013.3N 14.1E
Lake Chad is a historically large, shallow lake surrounded by Chad, Cameroon, Niger, and Nigeria on the edge of the Sahara Desert in Africa. It 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 considered to be one of the largest lakes in the world when first surveyed by Europeans in 1823. Lake Chad has shrunk considerably since the 1960s when it had an area of more than 26,000 km², making its surface the fourth largest in Africa. An increased demand on the lake’s water from the local population has likely accelerated its shrinkage over the past 40 years.
The size of Lake Chad greatly varies seasonally with the flooding of the wetlands areas. In 1983, Lake Chad was reported to have covered 10,000 km²-25,000 km² (3,861 mi²-9652 mi²), had a maximum depth of 36 feet, and a volume of 72 km3 (17.27 mi3).
By 2000 its extent had fallen to less than 1,500 km². A 2001 study blamed the lake’s retreat largely on overgrazing in the area surrounding the lake, causing desertification and a decline in vegetation. Others claim about half of the lake’s decrease is attributable to human water use such as inefficient damming and irrigation methods. Still others blame climate change for 50 to 75 percent of the water’s disappearance. Some consider it likely that the lake will shrink further and perhaps even disappear in the course of the 21st century.