目前風浪數值模式中的相位平均模式無法描述波浪折、繞射共存效應。為了要彌補模式的缺失，本文以 Hsu 等人 (2005) 提出之 WWM (Wind Wave Model) 風浪模式為基礎，參考 Holthuijsen 等人 (2003) 所提出的折、繞射耦合理論，並從延伸型緩坡方程式 (Evolution Equation of Mild Slope Equation，EEMSE) 中考慮海床坡度、海床曲率和波流交互作用之影響，經由交互疊代方式在 WWM 模式中考慮波浪折、繞射共存的機制。本文以三種等水深以及三種具坡度的地形配置進行模式驗證，同時與 SWAN、EEMSE 模式以及考慮緩坡方程式建立之 WWM 模式計算結果比較，以分析模式計算波浪繞射之合理性。數值計算結果發現，本文所應用的疊代技巧，不論波浪正向或斜向入射等水深或是等坡度上之結構物而產生之繞射效應，都能有良好的可靠性以及準確度。

Presently phase-averaged model wind wave numerical model cannot simulate combined effect of refraction-diffraction. In order to make up the shortcomings of the model, this paper used the Wind Wave Model (WWM) developed by Hsu et al. (2005), and consulted phase-decoupled refraction-diffraction effects proposed by Holthuijsen et al. (2003) to add refraction and diffraction in the WWM model. This study also applied Evolution Equation of Mild Slope Equation (EEMSE). The model includes the effects of the bottom slope, seabed curvature and wave-current interaction. For the rationality of using this model to computer wave diffraction, in this research we test three bathymetric landforms with constant depth and three slopes, and at the same time, this model is compared with SWAN model, EEMSE model and WWM model which matches up Mild Slope Equation. From the numerical result, no matter wave propagates in normal angle or oblique angle to produces diffraction effect in bathymetric landforms with constant depth and slopes, the skill using in this research obtained better reliable and accuracy solution.

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