Studies on swash marks and swash angles on texturally, tidally and morphodynamically-distinct beaches

Abstract

This study evaluates the prospects of a new dimensional attribute of swash marks, herein referred to as swash angle, as a signature of wave-beach interaction. Results from three open Atlantic sea coasts of Nigeria indicate predominantly obtuse swash angle values. Mean swash angle values and the deviation from the mean tend to increase on beaches exhibiting fine grain sizes, elevated tidal ranges and high dissipative process signatures. The converse is the case on the microtidal, coarse-grained reflective beaches. From the obtained results and other published information, it is conceptualized that for a given beach, smaller swash angle mean and deviation would express the potential towards rapid beach mobility. On the contrary, relatively stable beaches typical of the dissipative state would reveal large swash angle and large deviation of the latter.