IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) ALL CONTENT : Sediment management and morphodynamics : A laboratory investigation of wave-driven dune and beach morphology change under high storm surges
A laboratory investigation of wave-driven dune and beach morphology change under high storm surges
t scales and at different rates that depend on the surface wave forcing conditions and mean water level elevations. Storms deliver both energetic waves and elevated mean water levels, and can cause large volumes of sediment to erode and induce major changes over a short time. The present study uses a sand beach-dune system in the laboratory to understand wave-driven morphological evolution at high water levels. In a 35.5 m long, 0.9 m wide and 1.2 m deep wave flume with regular (monochromatic) waves that have a significant wave height of 0.15 m and propagate toward a 0.65 m high sand dune, erosion under two different water level regimes that represent high storm surges is investigated. The water levels correspond to the overwash and inundation regimes on the Sallenger (2000) storm impact scale for barrier islands. The work is intended as an extension of previous work focusing primarily on the swash, collision and overwash regimes. Waves are measured using six capacitance wave probes located along the flume, and morphological evolution of the beach-dune system is monitored throughout the experiments using a laser scanner. The final beach profiles are very different for the overwash and inundation experiments, with morphological equilibrium occuring after 1110 and 362 minutes of testing respectively. Landward recession of the dune crest is balanced in both cases by seaward advance of the beach toe and is variable in time due to the development and migration of sand bars. The observations indicate that severe erosion occurs in the inundation regime over a time scale that is much shorter than in the overwash regime, suggesting catastrophic destruction of barrier islands under extreme storm conditions.Form Required :Published Date : 123
File Size : 663,559 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) ALL CONTENT
Article : Sediment management and morphodynamics
Date Published : 20/08/2015
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