Effect of wave reflection on submerged plane slopes on the evolution of extreme wave fields

Describing intricate concurrent wave processes frequently proves challenging and unwieldy. Although the influence of reflection rates on the development of extreme nonlinear waves remains poorly understood, controversy has emerged over whether elevated reflection rates amplify nonlinearity in the upper tail of the wave height distribution. Aided by fully nonlinear simulations, we present a theoretical framework that isolates the effects of shoaling length, bottom slope magnitude, and reflection rates. Comparing the simulation results with the theory for steep and reflective slopes, it is noticed that the theoretical excess kurtosis stabilizes for steep slopes with a high reflection rate, and that the simulated kurtosis remains in the confidence interval of our new theory. We therefore conclude that the high reflection rate is the main reason for anomalous wave statistics becoming stable.