以往關於系列潛堤之布拉格反射研究，在規則波方面的理論、數值研究與分析都漸趨成熟，而實際應用於海岸保護時需考慮波浪為不規則波，因此本文之重點在於探討不規則波下之布拉格反射。首先在數值分析方面以許等人 (2003) 所發展的演進型緩坡方程式為基礎，並加上波譜分割的概念來模擬不規則波，同時進一步以水工模型試驗驗證數值模式之計算結果。本文同時根據數值和實驗之結果，歸納、探討各種布拉格反射現象可能之影響因子，發現不規則波之情況下，布拉格反射之帶寬較寬，且在複合式間距的潛堤佈置之下，反射效果優於等間距之佈置。

In this few decades, scholars paid attention to the research of Bragg reflection in regular waves. Thus, this study aimed to discuss the Bragg reflection in irregular waves. EEMSE is a numerical model based on evolution equation for mild-slope equation developed by Hsu et al. (2003). At first, we applied EEMSE to simulate the transformation of irregular waves propagating over the submerged breakwaters by splitting spectrum into several wave components. Meanwhile, we conducted experiments in wave flume and collected wave data from wave gauge. To compare results of numerical model with experimental data, we summarized some characteristics of Bragg reflection. We found that the reflection band is wider in irregular waves than that in regular waves. The reflection coefficient was higher when waves propagated over the composite submerged breakwaters.

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