Rainfall conditions in equatorial East Africa during the nineteenth century as inferred from the record of Lake Victoria

摘要

The East African lakes have exhibited dramatic fluctuations on both historical and paleo-climatic time scales. Levels of these lakes, and other historical indicators in Africa, suggested that environmental conditions in the nineteenth century were much more extreme than anything evident in the modern record. In this study, a water balance model is used to estimate the rainfall associated with these conditions, based on the Lake Victoria record. The results suggest that the conditions were not unlike anomalous periods found during the twentieth century, but they may have persisted for somewhat longer periods of time. The paper also demonstrates a generic tool that can be applied to interpreting historical and paleo-lake levels in quantitative terms of rainfall.