RAINFALL AND FLOW VARIATIONS IN THE LESOTHO HIGHLANDS

The Lesotho Highlands contain some of the highest mountains in souther n Africa and play an important role in the surface water resources of the region. Several features of the climatology and hydrology of the h ighlands are reviewed here. The emphasis is on the long-term response and the behaviour on an annual basis. Topics discussed include the var iations in rainfall with elevation and location, the relationships bet ween annual rainfall and river flows, and the variations over time in both rainfall and flow records. Results are presented in the form of u pdated versions of the mean annual precipitation and mean runoff coeff icient maps for the region, and examples are presented for typical reg ression relationships between flows and rainfall data on an annual bas is. Also, statistical analyses are described that suggest little evide nce for any significant cyclical behaviour or trend during the observa tional periods for either rainfall or flow data. (C) 1998 Royal Meteor ological Society.