The Cichlid Fishes of Lake Malawi, Africa

Abstract of Doctoral Dissertation

Xungang YIN
Florida State University, 2000
Adviser: Sharon E. Nicholson  

The water balance of the East African Great Lakes.  

The East African Great Lakes are important indicators of climatic and environmental change in an area where standard meteorological data are scarce. Three large lakes, Lakes Victoria, Tanganyika and Malawi are studied in order to build water balance relations between lake level and over-lake rainfall. By analyzing the satellite observations, the characteristics of the regional and mesoscale circulations are studied through analysis of convective activity and cloudiness over the lakes. Using a regression approach, the relationship between catchment rainfall and cold cloud frequency is found. Assuming the same convective mechanism operates for each lake and its catchment, the over-lake rainfall is calculated using the catchment rainfall, which has long records. Evaporation is estimated for each lake by energy-budget and Penman methods and a sensitivity study is also carried out. The available tributary inflow and lake outflow data of Lake Victoria are expressed by rainfall and lake level terms. For Lake Victoria, the water balance model is reformulated as a lake level model. The model is first used to predict the lake level changes as a validation. Then it is inverted so that the over-lake rainfall can be reconstructed from known lake levels in both modern times and historical times. In modern times, the precision is on the order of 1% for the calculated mean rainfall and a few percent for the calculated annual rainfall.




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