The surface area of the lake has decreased from 9,650 square miles (25,000 km2) in 1963 to 521 (1,350 km2) today. Modeling studies indicate the severe reduction results from a combination of reduced rainfall and increased demand for water for agricultural irrigation and other human needs.
Reference: Coe, M.T. and J.A. Foley, 2001. Human and natural impacts on the water resources of the Lake Chad basin, Journal of Geophysical Research (Atmospheres),106, D4: 3349-3356.
