Discussion of “A note on wave-induced set-up by obliquely incident waves” by T.T. Janssen and I.S. Jones, Coastal Engineering, 58, 812–814, 2011

Abstract

In the recent communication by T. T. Janssen and I. S. Jones (Coastal Engineering, 58, 812–814, 2011) the authors extend previous work on water level variations due to obliquely incident waves on a longitudinally uniform beach. Starting from the differential equation governing the mean transversal momentum balance, they derive an approximate solution for the wave-induced set-up which is validated by comparison with a more exact numerical integration. Here we show that such equation can easily by integrated analytically, giving a simple, exact expression for the variation of the mean level within the surf zone. The influence of the angle of incidence of the waves on the set-up is also clearly shown.