Maintenance of headland-associated linear sandbanks: modelling the secondary flows and sediment transport |
| |
| Authors: | Alexis Berthot Charitha Pattiaratchi |
| |
| Institution: | (1) Centre for Water Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009, Australia |
| |
| Abstract: | Linear sandbanks are located globally in areas where there are strong currents and an abundance of sand. In the recent years,
these sandbanks have become of strategic interest as a potential source of marine aggregates (sand and gravel) and mineral
deposits. They form the seaward boundary of the nearshore zone and therefore are important for the stability of the coastal
system. They also commonly reach the sea surface and thus pose a threat to navigation. Headland-associated linear sandbanks
are a specific type of sandbanks which are located in the lee of coastal topographic features such as headlands and islands.
Interaction between tidal currents and topographic features generate complex three-dimensional circulation patterns that significantly
influence the distribution of sediments in the vicinity of the feature. Field and numerical model investigations of the three-dimensional
flow structure have been undertaken on the Levillain Shoal, a headland-associated linear sandbank present in the lee of Cape
Levillain (Shark Bay, Western Australia). The field data indicated the presence of secondary flows near the tip of the cape
and around the bank which were re-produced in the numerical simulations. Numerical results have shown that residual eddies
are not representative of the sediment transport and that secondary currents enhance the convergence of sediment towards the
sandbank. Maintenance processes have been investigated. Sediment transport paths near the cape and the bank indicate that
the sandbank is part of a sand circulation cell where the sand is circulating around the bank with exchanges between the sandbank
and the headland. |
| |
| Keywords: | Sandbanks Headland Secondary flows Residual eddies Maintenance |
| 本文献已被 SpringerLink 等数据库收录！ |
|
