The farm Gamis is located about 250 km SW from Windhoek at the edge of the Namib. Mean annual precipitation is 177 mm with significant fluctuations in space and time. Extensive pastoral agriculture is supposed to be the appropriate type of land use in this ecologically sensitive region where much of the land is now degraded due to overgrazing in the past. At the Gamis farm, Karakul sheep are kept for the production of furs. The farmland (30 000 ha) is divided into 98 paddocks, approximately 60 of them are used for the grazing of (up to three) fur production flocks. A sophisticated grazing rotation system has prevented the land from degradation, whilst at the same time guaranteeing the farm's economic survival. This management strategy is studied as an example of sustainable land use. A computer simulation model is constructed in order to understand the basis of this strategy's success and to apply this knowledge to other situations. The model is a top-down approach that simulates rainfall and development of the vegetation according to long-term observations by the farmer. Rules of the rotation system have been included in the model. Variations of the rules are analysed to compare different strategies. Model results show that the farmer's strategy is able to cope with aridity in general and particularly with the typical occurrence of periods of drought to be found in this region. Alternative strategies are found to be less successful.