The Impact of Rainstorm Stochasticity on Hillslope Sediment Supply to River Channels in Dryland Basins

摘要: Climate interacts with hillslopes supplying sediment to river channels, and impacting drainage basin functioning and evolution. In particular, coarse sediment supply from hillslopes exerts a strong control on channel bed material grain-size distributions (GSD) which feeds back on bedload flux and consequently affects long-term rates of valley incision/aggradation. However, process-based understanding of sediment supply from hillslopes is poorly constrained because it is spatially and temporally variable as a result of interactions between rainstorm attributes (frequency, intensity, duration, size) and hillslope characteristics within a basin (length, gradient, infiltration rates, GSD). Drylands are particularly sensitive to climatic forcing because they are subjected to infrequent, short-lived, but high intensity rainfall events, which are spatially-variable and often smaller than the basin area. These climatic factors coupled with …