Sediment transport by shallow flows impacted by pulsed artificial rainfall

Abstract

In many experiments using rainfall simulators, rainfall is applied to the target as a high intensity pulse so that there are often long periods when the soil receives no rain and there are short periods when the soil receives rain at an extremely high intensity. Because concerns exist about the use of such methods of applying rain in experiments designed to help predict erosion under natural conditions, experiments using intermittent and continuous artificial rainfall were performed and analysed in terms of a recently developed theory on erosion by rain-impacted flow. The results indicate that the manner in which the rain is applied does not significantly influence the time-averaged sediment discharge from the sediment transport perspective. However, if high intensity, high energy pulses of rain influence factors which affect the susceptibility of the soil to erosion differently to continuous rain, then concerns about the use of intermittent rainfall in soil erosion experiments remain.