Faculty of Natural and Agricultural Sciences
School of Physical Sciences
Department of Geography, Geoinformatics and Meteorology
Selected Highlights from Research Findings
Funding was received from the British High Commission in South Africa to implement a Numerical Weather Prediction (NWP) system for countries over equatorial Africa. Uganda, and in particular, the Uganda Department of Meteorology has been selected as pilot for this initiative.
Achievements are that the project team managed to install a model and to produce daily forecasts of four days in advance on a routine basis for Uganda (15km x 15km resolution), Lake Victoria (8km x 8km resolution), South Africa (15km x 15km resolution) and the Eastern Highveld of South Africa (8km x 8km resolution).
The computer and networking for this is provided by the BEE company Tabia Endelevu Africa (TEAfrica: meaning “Environmental Development Africa” in Swahili). Through the project TEAfrica and the University also managed to do infrastructure development at the national weather forecasting office of Uganda at Entebbe.
A new nonhydrostatic atmospheric model has been developed based on an equation set not applied before in atmospheric modelling, and employs a novel split semi-Lagrangian numerical solution procedure.
The numerical scheme is stable at large advection time-steps and is formulated on a nonstaggered grid that makes it computationally highly efficient. The model has been used to study highly nonhydrostatic and nonlinear flow in a series of bubble convection experiments. It may be used in the future to study the characteristics of nonhydrostatic circulation over South Africa, such as severe thunderstorms and mountain waves.
Research in Namibia has focussed on rainfall and sediments. In the past seven years alone, Namibia has experienced three rainy seasons, 2000, 2004 and 2005/2006 with abnormally high precipitation. Research has focused particularly on the geomorphological implications of the rainstorms, the type, frequency, magnitude and overall intensity of flooding and the extent of damage.
Late Pleistocene to Holocene valley fill sediments from several catchments within the Escarpment region of southern Namibia (Huns River and tributaries, Boom River) were investigated and palaeoenvironmental scenarios were reconstructed with respect to the rainfall regime, runoff dynamics and depositional environments (fluvial, wetland, lacustrine).
Rich organic material findings from palaeosols provided series of radiocarbon dates which are presently being correlated with findings from neighbouring catchments
Contact person: Prof CJdW Rautenbach.
|
