Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor | Department of Civil and Environmental Engineering | en_US |
| dc.contributor.advisor | Stocchino, Alessandro (CEE) | en_US |
| dc.creator | Bagnasco, Tiziano | - |
| dc.identifier.uri | https://theses.lib.polyu.edu.hk/handle/200/14585 | - |
| dc.language | English | en_US |
| dc.publisher | Hong Kong Polytechnic University | en_US |
| dc.rights | All rights reserved | en_US |
| dc.title | A multi-scale investigation of waves in the South China Sea : integrating hindcasts, trend analysis, multifractal signatures, and nature-based solutions | en_US |
| dcterms.abstract | The South China Sea (SCS) is a region of critical economic and ecological importance, subject to complex wave climates influenced by monsoon systems and climate change. However, a comprehensive, holistic understanding of its wave dynamics, from basin-scale extremes to coastal interactions, is still needed. This thesis aims to provide a high-resolution, multi-scale characterization of wave processes in the SCS. It specifically investigates long-term trends in annual maximum wave heights, their underlying multifractal properties, and the efficacy of mangroves as a natural coastal defense. | en_US |
| dcterms.abstract | To achieve this, a two-way coupled wave-current high-resolution hindcast was developed for the SCS. A more specific treatment was reserved for typhoons and extreme events, that were simulated with the Holland parametric wind model. The hindcast data were then analyzed using a non-stationary extreme value approach to characterize significant wave height trends and for return level estimations. Moreover, a multifractal detrended fluctuation analysis (MF-DFA) was performed to the significant wave height series to uncover their scaling properties. Finally, the wave dissipation capacity of mangroves was quantified through a focused case study in the Mai Po Nature Reserve, Hong Kong. | en_US |
| dcterms.abstract | The results reveal a solid performance of the SCHISM-WWMIII model, with the wave-current coupled hindcast providing robust nearshore skills, enhanced by the Holland model for accurate typhoon peak HS and storm surge predictions. Non-stationary extreme value analysis identifies significant wave height trends, with most pronounced negative trends of about -0.045 m/year in northern and eastern SCS and positive trends up to around 0.019 m/year in southern regions, amplified by 20-30% during typhoon seasons, and 25-year return levels reaching 12 m in central-northwestern SCS, with projected increases by 2122. MF-DFA uncovers synoptic (10-21 days), seasonal (5-7 months), and inter-annual (1.4-1.7 years) time scales, with northern SCS showing super-persistence (Hurst exponents > 1.8) and southern regions greater stability. Mangrove dissipation at Mai Po reduces wave heights from 1.2-1.7 m offshore to centimeters inland, primarily due to the effects of a shallow bathymetry, indicating that the effects of vegetation are marginal. | en_US |
| dcterms.abstract | This research establishes a robust numerical framework and provides novel insights into the non-stationary and multiscale nature of SCS waves. The findings have direct implications for coastal hazard mitigation, climate adaptation planning, and the conservation of nature-based coastal defenses like mangrove ecosystems. | en_US |
| dcterms.extent | 1 volume (various pagings) : color illustrations, maps | en_US |
| dcterms.isPartOf | PolyU Electronic Theses | en_US |
| dcterms.issued | 2026 | en_US |
| dcterms.educationalLevel | Ph.D. | en_US |
| dcterms.educationalLevel | All Doctorate | en_US |
| dcterms.accessRights | open access | en_US |
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