本文應用緩坡方程式模擬不規則波之變形，對於不規則波之處理採用波譜分割法，並以能量通率之觀點在緩坡方程式中加入能量消散係數，處理非線性淺化效應、碎波效應及非線性波波交互作用，據此建立一數值模式模擬波浪通過不規則地形時之波高、週期與波譜形狀之變化。模式計算結果經與不規則波之試驗結果比較後得知：波高模擬方面，本文計算結果與試驗結果呈現合理之一致性；波譜變形方面，本文因考慮非線性波波交互作用，故模式能改善未考慮非線性交互作用時對於波譜主頻能量高估之情形，且在非線性參數 Ur 介於 0< Ur <100 之範圍時，模式計算所得之波譜與實測波譜呈現良好之一致性。而在 Ur >100 時，本文模式有低估波譜能量往高頻區轉移之情形，因此對於波譜高頻區之形狀模擬能力較低。

In this paper, a numerical model based on mild-slope equation is constructed to simulate transformation of irregular waves. First, we apply spectral method to separate the significant wave spectrum into several component waves, and add the energy coefficient into the governing equation in terms of energy flux to deal with nonlinear shoaling、wave breaking and wave-wave interaction. The validity of the present model is verified through comparisons with experimental data. For simulation of wave height, the present model shows reasonable results with measured data. And for transformation of wave spectrum, the present model improves the overestimation of energy in peak frequency when wave-wave interaction is included. Comparisons of measured data and numerical results indicates that the present model has good ability for simulation of spectrum shape when 0< Ur <100 . But when
Ur >100, the present model underestimates the energy transferring to higher frequency of spectrum.

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