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

Abstract

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.

Natural and Anthropogenic Factors Shaping the Shoreline of Klaipėda, Lithuania

“…The jettie's seaport systems on a straight sandy shore block the natural littoral drift [47,48], which determines the development of shoreline configurations. Typically, an up and down littoral drift is formed when hard breaking structures interrupt the predominant sediment transport direction.…”

Coastal Zone Changes in West Africa: Challenges and Opportunities for Satellite Earth Observations

“…Coastal erosion is widespread in the region, with significant effects on coastal ecosystem functioning and livelihood support. Although the coastline is highly sensitive to natural erosion and sedimentation processes due to natural changes in wave regime, strong longshore drift transport, and river flow due to rainfall variability, human activities have intensified coastal erosion, including sand mining, disruption of hydrological cycles, construction of dams on rivers, construction of ports, dredging and deforestation of mangroves, etc., 2009;Laibi et al 2014;Ozer et al 2017;Sadio et al 2017;Angnuureng et al 2018;de Boer et al 2019;Giardino et al 2017a;Ndour et al 2018;Almar et al 2019;Anthony et al 2019;Abessolo et al 2021).…”

Modelling Coastal Development and Environmental Impacts: A Case Study Across Two Regional Towns in Australia

“…The indicator developed for coastal erosion was the land surface area (sqm) of the GORCC management area lost/change due to shoreline retreat. The methodology followed for coastal erosion was based on the Aqua Monitor method [70,71], providing plausible results for a first pass assessment for coastal shoreline retreat The majority of the northeast of the study area in Torquay will be affected by sea-level rise. The results show that no buildings will be affected by sea-level rise, however, assets impacted will include emergency markers, sealed walkways, stairs, beach access trails, boardwalks, beach areas, coastal walking paths and vehicle access paths.…”