一、引言 沿海岸各种工程的设计以及对海岸演变过程的了解,要求我们必须知道靠岸水波的能量是如何变化的。很明显,波在进入海滩或浅水域后的能量有赖于它在深水时的能量,而能量的分布又会受到折射、反射以及绕射等的影响。在目下研究中,只考虑了波的折射效应,绕射、海底反射及以摩擦、渗透等引起的波能损失被忽略了,因为一般说来它们可认为是小的。 根据线性理论知道,波的相速度为 I. INTRODUCTION The design of various projects along the coast and their understanding of the evolution of the coast requires that we must know how the energy of the docked waves changes. Obviously, the energy of waves entering the beach or shallow waters depends on the energy of the waves in deep water, which in turn is affected by the refraction, reflection and diffraction. In the present study, only the refraction effects of waves are taken into account. The diffraction losses, wave reflection, and loss of wave energy due to friction, infiltration and so on are neglected because they can generally be regarded as small. According to the linear theory, the phase velocity of the wave is