Effect of morphologic and hydraulic factors on hysteresis of sediment transport rates in alluvial streams

摘要

Unsteady flow events, such as those caused by extreme precipitation events or reservoir flushing, can result in hysteresis of sediment transport rates in alluvial streams. Over the past 20years, several experimental studies have been conducted that monitored sediment transport rates in response to unsteady flow event hydrographs. Previous literature has identified numerous morphological and hydraulic factors, including sediment composition, sediment supply, hydrograph characteristics, bed morphology, and mode of sediment transport, that affect hysteresis of sediment transport rates. This manuscript reviews and evaluates the degree of influence of these factors on hysteresis in order to develop a comprehensive understanding of the dominant factors responsible for this phenomenon. This systematic evaluation suggests that the mode of sediment transport and sediment composition are the most dominant factors influencing the resulting type of hysteresis. Further research is required to investigate the effect of other factors, such as non-uniform stream bed composition and planform geometry, and develop predictive models to assess the sediment transport response to unsteady flow events.