A REVIEW AND UPDATE OF THE HYDROLOGY OF LAKE VICTORIA IN EAST-AFRICA

Water balance models have been used to examine trends in the level of Lake Victoria over this century. A monthly model developed in a previo us study for the period 1925 to 1978 has been improved and the simulat ion period extended to 1990. Also, an annual model has been used to ex tend the water balance back to the start of the century. The simulatio ns confirm the results from previous studies which showed that the obs erved variations in lake level can be explained primarily in terms of natural variations in rainfall over the lake and surrounding basin. An idealized interpretation of these variations is presented which illus trates the long response time of this large lake and which is used to speculate on the likely future behaviour of the lake.