Wave Runup on Beaches

Runup on beaches is an important topic in coastal engineering because it defines the upper limit of direct wave influence on land. It is also a phenomenon that has proved very difficult to analyze and characterize in a quantitative manner. The reason for this difficulty is the more general problem of understanding the response of beaches to waves. This paper develops formulas to estimate the approximate upper limit of wave runup on sand and gravel beaches. The relationship between these formulas and recent progress in quantifying beach profile response to waves and the morphodynamics of beaches is discussed. It was found that estimates of wave runup on sand beaches could be improved if sediment sizes in both swash zone and surf zone are known.