Water and Energy Abstracts
  • Year: 2005
  • Volume: 15
  • Issue: 2

28. Episodic Sediment Pulses Generated by Forested Flood Plain Stripping: Bruces Creek, Nadgee State Forest, Southeastern Australia

  • Author:
  • Ashley A. Webb, D. Dragovich
  • Total Page Count: 1
  • Page Number: 12 to 12

(Sediment Transfer through the Fluvial System – Proceedings of a Symposium held in Moscow, August 2004 – IAHS Publication 288, 2004, pp. 13–20).

Abstract

Sedimentological, stratigraphic and radiocarbon analyses of flood plain sediment indicate that flood plain pockets of Bruces Creek, a sand-bed forest stream, were completely removed by a catastrophic flood around 1000 years BP. The present flood plain redeveloped by lateral migration prior to 575 years BP and was colonised by an emergent Eucalyptus forest and Tristaniopsis laurina (Water Gum) trees. Since 300 years BP, channel stability has been controlled by riparian vegetation and large woody debris (LWD), as indicated by obliquely accreted fine-grained sediment deposits on the channel banks. This work indicates that sediment transfer through small sand-bed forest systems is minimal during extended periods of vegetation-controlled channel and flood plain stability. However, episodic high-energy catastrophic floods can exceed thresholds of channel stability, totally destroy alluvial landforms and the flood plain forest, and result in the delivery of massive pulses of sediment to the channel.

Keywords

Catastrophic erosion, Catastrophic floods, Flood plain stripping, Riparian vegetation, Sediment transfer, Southeastern Australia