干旱区生态环境知识资源中心

High-magnitude winds in the Namib Desert region carry out significant modification to the landscape and mobilise considerable loads of mineral material on a few days each year. The lack of weather stations along this coastal desert and the limited perspective provided from ground based observations limit our understanding of such 'events'. In order to identify the spatial patterns of dust storms, in particular their source areas, hand-held photographs mainly taken from the Space Shuttle were used. This in addition to other remotely sensed data provides the only satisfactory source of information concerning short-lived dust 'events'. Imagery and photography also yield information concerning time and date which in conjunction with a state-of-the-art analysis forecast model from the National Center for Environmental Prediction (NCAR) and National Center for Atmospheric Research (NCAR) will provide insight into synoptic conditions, which promote dust generation. Results indicate that dust outbreaks along the Southwest coast of Africa occur most commonly during the creation of subcontinental ridging anticyclones over the winter months (April to November). Productive dust surfaces arc salt pans along the coast and the interior, dry river channels, areas of agricultural activity and desertified areas with rural overpopulation.