Study of the Durban Bight shoreline evolution under schematised climate change and sand‑bypassing scenarios

Abstract

The Durban Bight beaches, on the KwaZulu-Natal coast of South Africa, have been the topic of several studies in the past, because of their recreational and economic value. These beaches are mainly nourished via a sand-pumping scheme, which has been the case since the 1980s. The present study investigated the longer-term dynamic stability of the Durban Bight beaches using a one-dimensional numerical shoreline model. The wave conditions that drive the longshore transport of sand were simulated using the numerical spectral wave model Simulation WAves in the Nearshore (SWAN). The shoreline model was calibrated and validated against existing historical data. The calibrated model was then employed to simulate possible future scenarios. These included climate change phenomena and the influence of anthropogenic changes. Each of the simulations predicts a twenty-year period, with results extracted at five-year intervals. The results are presented and discussed, and the emphasis is placed on the importance of maintaining the required sand-bypassing rates and the awareness of the possible effects of climate change on shoreline maintenance and management.