Variations of African lakes during the last two centuries

The historical levels of numerous African lakes have been derived, using detailed geographical and historical descriptions of the lakes. Reconstructions have been completed for Lakes Chad, Victoria, Naivasha, Turkana, Stefanie, Tanganyika, Rukwa, Malawi, Chilwa and Ngami. In all cases information is available back to the beginning of the nineteenth century; it becomes plentiful, allowing for almost year-to-year histories, around the 1850s. For numerous lakes, a general overview of levels during prior centuries has also been derived. For select lakes, a comparison is made with the modern hydrological regime. The most striking periods are early in the nineteenth century when dramatic recessions were ubiquitous, and during the latter decades of the century when dramatic rises of the lakes occurred. Water balance models are used to approximate the changes of rainfall associated with these periods. Comparisons are made with anomalous periods during the twentieth century: the 1910s and the 1960s and 1970s.