Lake Malawi/Nyasa: an investigation of the causes of the recent high levels

The level of lake Malawi rose by over 2.5 metres between 1960 and 1979. Following a slight fall the lake began to rise again and by mid 1980 had risen a further 0.2 metres to a level of 475.85 metres a.s.l, the highest level recorded since the beginning of this century. Because these recent rises are in contrast to the previous long period of relatively stable levels they aroused considerable interest. High lake levels resulted into both flooding and erosion along both the lake and its major outlet, the Shire river. This study examines possible man-made and natural causes for the rises and opts for an increase in over-lake precipitation as the most likely cause. A Quantitative analysis of each of the components of the water balance namely; rainfall, inflow, outflow change in storage and evaporation has been done each as an independent chapter. Lastly, comparison is also made with similar rises in other East African lakes.