Causes of spatio-temporal variations in the flood event efficiency index

Abstract

Spatio-temporal variation of suspended sediment load is a topic of real interest in river geomorphology, especially in the current context of climate change and increasing anthropogenic impacts. In the present study, an attempt was made to argue for these variations based on the correlations between the event efficiency index and the degree of sediment availability in river channel following flood events. Data from four gauging stations along the Trotuș River (Romania) were used to show these types of relationships. The results show that the spatial variations of the event efficiency index are in close correlation with the characteristics of the riverbed in the sectors analysed, and the temporal variations reflect the role of flood events in the modification of river channel and the availability of sediment. Major flood events have caused visible changes in the suspended sediment flux, which is why the analysis of the spatial and temporal variations must necessarily take into account the characteristics of the river channel in terms of sediment sources.