Improved Maximum Run-Up Formula for Mixed Beaches Based on Field Data

In Southeast England, more than 30 coastal frontages (>180km) have a mixed sand and shingle beach as the main defence against the risk of flooding or erosion. Presently, understanding of run-up and overtopping of mixed beaches is considered to be poor and approaches to calculate run-up usually rely on formulae developed for structures or have been largely developed in laboratory environments using single grain size with associated problems in applying results to mixed sediments. This paper uses almost 400 field measurements of maximum run-up from several sites in Southeast England together with concurrent wave and water level data to develop and test a new maximum run-up formula.