Runup of breaking solitary waves on rough uniform slopes

Abstract

An experiment consisting of 122 tests was conducted for breaking solitary waves on rough and smooth slopes. The constant water depth and the incident wave height were varied to cover a wide range of solitary wave nonlinearity, i.e., from 0.039 to 0.458. Free surface elevations, velocities and maximum runup heights were measured for four slope surfaces of different roughness. A surf similarity parameter proposed previously for smooth slopes was used to analyze the runup data on rough slopes. A reduction factor was introduced to compare the runup heights of breaking solitary waves on rough and smooth slopes and to unify the runup formula for smooth and rough slopes. The fitted reduction factor for each of the rough surfaces was less than unity (smooth slope) and in the range of 0.48–0.88. Existing runup formulas are used to confirm the accuracy and applicability of runup height predictions. The measured free surface elevations and velocities were analyzed to quantify the roughness effect on solitary wave runup. Laboratory observations reveal that the slope roughness noticeably influences the hydrodynamics in the surf and swash zones.