Poster Number 18
See more from this Division: General Discipline Sessions
See more from this Session: Geomorphology (Posters)
Abstract:
Fowlers Creek is a significant regional ephemeral drainage system arising in the Barrier Ranges north of Broken Hill, in far western New South Wales, Australia. The channel is dry for most of the year, but occasional floods recharge water stores in channel-margin sediments. Consequently, the channel, like many other Australian ephemeral streams, supports riparian corridors of large trees (Eucalyptus camaldulensis, the river red gum) as well as tree growth on the stream bed itself.
River red gums drop many branches to the stream bed during dry weather, and this woody debris is swept up by flood flows, to lodge in large accumulations of detritus, often trapped on the upstream side of channel-bed trees. In some cases, gaps in the woody debris barriers are plugged by accumulations of fallen leaves and twigs, and by mud. These barriers may extend across the entire width of the channel, and in such cases, cause upstream impoundments where flow speeds are reduced and muds settle from suspension to clog the pore spaces within channel-margin sediments. Surficial mud drapes are also set down. These sediment clogs and mud drapes then reduce the rate of seepage loss that would otherwise occur in the impoundments. Elsewhere, the debris barriers generate significant scour and fill, or deflect erosive currents against the bank, triggering channel realignment.
See more from this Division: General Discipline Sessions
See more from this Session: Geomorphology (Posters)