This study reports of the results of extensive field monitoring of river
flows and lake levels, rainfall and evaporation. The study’s aim was to elucidate main trends and
periods of meteorology and hydrology as revealed by time series of rainfall, evaporation, river
discharge and lake levels and which could be used as input towards computation of nutrient and
sediment load introduced into Lake Victoria.
Hydro-metrological data for the period running 1950-2004 were analysed and form the basis for
computing the pollution loadings (catchment and atmospheric) into the lake and as well as
calculation of the lake water balance. Continuous rainfall and evaporation records were applied and
data gaps filled were necessary. Full records of land discharges were obtained from rainfall
records using the NAM model. Model performance was evaluated on the ability to simulate the total
flow for catchments, rather than the peak and minimum flows, for pollution estimation.
The implication of the results in the eutrophication related processes in the
lake are also discussed in this report.