Mapping the Sandy Beach Evolution Around Seaports at the Scale of the African Continent

Journal of Marine Science and Engineering

Gerben Hagenaars¹  Wiebede Boer²  Tiedo Vellinga²  Sierdde Vries²  Jill Slinger³  Yongjing Mao⁴ 

[1] Department of Harbour Coastal & Offshore Engineering, Deltares, PO Box 177, 2600 MH Delft, The Netherlands;Faculty of Civil Engineering and Geosciences, Delft University of Technology, PO Box 5048, 2600 GA Delft, The Netherlands;Faculty of Technology, Policy and Management, Delft University of Technology, PO Box 5015, 2600 GA Delft, The Netherlands;School of Earth and Environmental Sciences, University of Queensland, St Lucia, Brisbane, QLD 4072, Australia;

关键词: coastline dynamics;    coastal erosion;    sediment transport;    port design;    satellite imagery;    sustainable ports;   

DOI  :  10.3390/jmse7050151

来源: DOAJ

【 摘 要 】

In Africa, several new seaport developments are being considered. In sedimentary environments, such port developments can have adverse impacts on the evolution of adjacent coastlines. To learn from past port engineering practice, we created a unique database containing the coastline evolution and characteristics of 130 existing African seaports. Whereas the systematic mapping of coastal impacts was previously hampered by data availability, innovative automated satellite image processing techniques have enabled us to intercompare ports at an unprecedented continental scale. We found large geographical differences with respect to the beach evolution. The total detected changes in the beach area between 1984 and 2018 totaled 44 km², of which ca. 23 km² is accretion and ca. 21 km² is erosion. The top 10% “hotspot„ ports account for more than 65% of these changes. These hotspots exhibit common characteristics, namely: they are located on open coastlines, have large alongshore sediment transport potential, and have large cross-shore breakwaters. Although these driving characteristics are well established in coastal engineering theory, our results indicate that the beaches adjacent to the existing seaports have been and remain seriously affected by these drivers. Our results can be used to inform beach maintenance strategies for existing seaports and to support planners and engineers to minimize long-term coastal impacts of port expansions and new port developments in Africa in the future.

【 授权许可】

Unknown