The Review of the Rate and the Hydrological Significance of the Fast Drying Up of Lake Chad

摘要

Lake Chad is a tectonic lake formed as a result of earth movement. The lake is shared by five countries of Cameroon, Chad, Nigeria, Niger and the Central Africa Republic. Over thirty million people depend solely on the renewable natural resources of the basin for agriculture, animal husbandry, fisheries, recreation and other socio-economic activities. The Lake is in a hot and arid climate, where the rate of evaporation exceeds precipitation. The essence of this study is to access the causes of the decline in volume of the Lake and to proffer solutions. Satellite imageries of 1963 to 2000 were observed and they reveal that the lake has been environmentally reduced to cover only about 3% of its 1963 area size. The hydrostratigraphy and hydrodynamics play a role in the recharge of the lake. The upper aquifer of the southwest portion of the basin consists of a Quaternary phreatic aquifer made up of fine-grained sediments approximately 30 m thick and is hydrologically connected to the Lake. Anthropogenic influence on the Lake is worrisome. The excessive use of lake waters for irrigation and construction of dams are causing a massive reduction in the water volume. A similar environmental disaster occurred in Lake Aral in the Former Soviet Union. Unsustainable water management is complicated by lack of proper irrigation systems and resulting in salt accumulation in the soil. The countries of the LCBC have drawn out modalities for saving the lake which includes channeling the Bangui River from the Central Africa Republic to the lake. Anthropogenic activities need to monitored and planned in such a way that runoffs are redirected into the lake. A proper articulated hydrogeosystematics is required to solve the ecological mayhem and to safe the riparian countries from hydrogeonthropocide.