A CHARACTERIZATION OF SOUTHERN AFRICAN ESTUARINE SYSTEMS

Summary Modifications to the structure and functioning of southern African estuarine systems can be placed into two major categories; those changes that have been driven by global forces such as climatic and sea-level fluctuations, and those that have resulted from direct human interference and are of a local or regional nature. Both the above categories will determine the rate and magnitude of physiographic and hydrodynamic changes within southern African estuaries, and therefore have a major impact on the characterization of individual systems in the future. Although the fluctuating nature of southern African estuaries (on both a spatial and a temporal scale) makes it difficult to place individual systems in distinctive categories, a classification system is possible if the dominant conditions in a particular estuary are assessed. Using a combination of physiographic, hydrographic and salinity features, five types of systems are recognised in this review, viz. permanently open estuaries, temporarily ope...