Numerical investigation of effects of artificial excavation pit on transformation and runup processes of tsunami-like wave over fringing reef. (15th February 2023)

• Record Type: Journal Article
• Authors: Qu, K.; Huang, J.X.; Yao, Y.; Guo, L.; Wang, X.; Li, X.H.; Jiang, C.B.
• Is Part Of: Ocean engineering. Volume 270(2023)
• Publication Date: 2023-02-15
• Subjects: Excavation pit -- Fringing reef -- Numerical simulation -- Two-phase flow -- Solitary wave; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2022.113553
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: In recent years, excavating materials from the reef flat gradually becomes the main source of sand and aggregate for the coral-lined coasts in tropical and subtropical regions, especially the low-laying atoll islands. These artificial excavation pits are bound to have significant impacts on the wave hydrodynamics over the fringing reefs. However, effects of the excavation pit on the hydrodynamic characteristics of tsunami-like wave over the fringing reef are few studied. To fill the knowledge gap of previous research, effects of artificial excavation pit on the transformation and runup processes of tsunami-like wave over the fringing reef have been systematically investigated in this study based on a high-resolution two-phase flow model. Effects of several main factors are carefully discussed. Research results indicate that the presence of excavation pit can have noticeable influences on the wave transformation and runup processes of tsunami-like wave over the fringing reef. Complex interactions between the breaking surge bore and the water body in the excavation pit can be observed. The complicated flow field in the pit can dissipate more wave energy and result in a lower maximum wave runup height. However, the local wave height near the pit in most situations can be amplified. It is hoped that the research findings can broaden the understandings on the wave hydrodynamics over the fringing reef with the artificial excavation pit. Highlights: Effects of artificial excavation pit on the transformation and runup processes of tsunami-like wave over the fringing reef are investigated by applying a two-phase numerical model. Influences of main factors, such as wave height, water depth, pit location, pit depth and width, forereef and backreef slopes, and reef-flat length are discussed in detail. Results indicates that the presence of artificial excavation pit can significantly influences the hydrodynamic characteristics of tsunami-like wave over the fringing reef.