Wave shoaling over steep slopes-An experimental investigation

Shoaling characteristics of waves on steep slopes are unique due to significant reflections. Wave heights on steep slopes are altered in a way that is different from wave interaction with mild slopes. Studies on detailed characterization of such phenomenon on steep slopes are scanty. In this study, an attempt has been made to quantify the wave shoaling coefficient (Ks) on steep slopes. Wave shoaling and reflection characteristics are studied on steep sloped (1/2.8, 1/3.8, 1/5.6), smooth and impermeable beaches a physical wave tank facility. The thorough analysis of experimentally measured wave heights along the steep slopes revealed that Ks is influenced by relative depth which is the ratio of shoaling depth (dsh) and shoaling wave length (Lsh) as well as surf similarity parameter (ξ) and this led to an empirical formula between Ks and other important parameters related to initial wave and beach slope conditions. Through this study, application of linear wave theory (LWT) has been extended for the estimation of shoaling coefficients on steep slopes, which otherwise reported to be not applicable. The derived empirical relations were also tested for the results obtained from experiments performed on a gentle slope (1/100) for similar test conditions. The details of experimental program, analyzing methodology and results are discussed in this paper.