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

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

de Boer, W.P. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Deltares)
Mao, Yongjing (University of Queensland)
Hagenaars, Gerben (Deltares)
de Vries, S. (TU Delft Coastal Engineering)
Slinger, J (TU Delft Policy Analysis; Rhodes University)
Vellinga, T. (TU Delft Rivers, Ports, Waterways and Dredging Engineering)

2019

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.

Coastal erosion
Coastline dynamics
Port design
Satellite imagery
Sediment transport
Sustainable ports

http://resolver.tudelft.nl/uuid:3ea6e669-6f0b-4b60-8d21-fa96dec7f9c9

https://doi.org/10.3390/jmse7050151

2077-1312

Journal of Marine Science and Engineering, 7 (5)

Institutional Repository

journal article

© 2019 W.P. de Boer, Yongjing Mao, Gerben Hagenaars, S. de Vries, J Slinger, T. Vellinga