Review of coastal currents in Southern African waters

Abstract

A review has been made of existing knowledge of the coastal currents in Southern African waters between Pretoria to Oudtshoorn on the northeast border, and the Orange River on the west coast. These waters have been divided into five sectors. For each, the larger scale forcing mechanisms are discussed and the results of localized studies summarized. The former involve consideration of, inter alia, the influence of the Agulhas Current on the east coast and the wind stress on the south and west coasts. The latter, the local studies, contain the results of investigations which have been carried out mainly for coastal engineering and effluent problems - and tend to be concentrated around built-up, or developing regions. They are consequently unevenly spaced. In regions where such studies were not available, recourse had to be made to ships' drift reports. Because of the nature of the data it was necessary to restrict the review, almost entirely, to surface currents. Where possible, wave driven currents - near shore circulations - have been included. In planning the review the needs of the user of coastal currents data were a primary consideration. Where important information has been found lacking recommendations for future research have been made. An appendix contains brief descriptions of the more widely used methods for measuring coastal currents.