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A workshop on swash-zone processes was convened in July of 2014 aimed to present the most recent research advances and to identify topics of future research. This paper presents the most critical topics discussed at the workshop with future perspectives. Recurring themes throughout the workshop (and this paper) are the ability to tie the research to problems of societal interest, focus efforts on understanding extreme conditions, and improve sediment transport and morphodynamic prediction from numerical models. Subsequent papers in the special issue highlight recent advances in swash-zone processes research. [ABSTRACT FROM AUTHOR]

Abstract: A technique is described to observe and quantify wave-by-wave bed-level changes in the swash zone. The ultrasonic instrument system is non-contact with the beach face surface being measured and the sensors remain outside of the fluid flows causing sediment movement. Sensor resolution combined with the electronic noise inherent within a digital network data-logging system results in a (conservative) measurement accuracy of ±1 mm, equating to a couple of sand grain diameters in height. Illustrative field results demonstrate the practical use of the instrumentation, and a simple data pre-processing method to separate swashes and intervening bed-level ‘events’ is discussed. These example data reveal rather complex fluctuations of the bed observed over time periods of minutes to hours. Rather strikingly, gross bed-level changes per wave are revealed to be up to many orders of magnitude larger than the observed net rate of beach face evolution. It is outlined how observations of successive bed-level changes at multiple locations within a dense grid, combined with a consideration of sediment continuity, will now enable the total net sediment transported per uprush–backwash to be quantified. [Copyright &y& Elsevier]