Suspended sediment concentrations and the geomorphic effect of sub-bankfull flow in a central Australian stream

摘要

Data on suspended sediment concentrations (SSC) and channel change following a series of flows during 1995 are presented and compared with previously unpublished SSC for the region. Suspended sediment concentrations for the Todd River are generally lower than for other arid regions of Australia. Data are poorly correlated with discharge and peak concentrations reflect bed load entrainment at individual hydrograph peaks following troughs in multi-peaked flows. Peak SSC are higher for low flows, most likely, a dilution effect. Sub-bankfull flows are important agents of minor channel change and proto-flood-plain construction processes. Adjustments include the lateral filling of width irregularities, the formation and accretion of flood plain insets, the deposition of flood plain veneer and thalweg incision.