Large-scale patterns of erosion and sediment transport in river networks, with examples from Australia (vol 52, pg 91, 2001)

This paper examines the patterns of sediment transport in rivers in terms o f the sources of sediment and its transport and deposition through the rive r network. The analysis is in the context of dramatic human influences on r iver sediment transport and how they might influence freshwater ecosystems. The review of Australian work shows that erosion of hillslopes and stream banks has greatly increased in historical times, supplying vast quantities of sediment to rivers, much of which is still stored within the river syste m. The stored sediment will continue to effect in-stream and estuarine ecos ystems for many decades. In most Australian catchments the dominant source of sediment is streambank erosion. An analysis of historical channel wideni ng suggests that a conceptual framework of relative stream power can explai n the diversity of behaviour observed in the numerous case studies. Sedimen t delivery through catchments is considered first in a generic whole networ k sense, which emphasizes the crucial role played by riverine deposition in determining catchment sediment budgets. A method is then presented for ana lysing the diverse spatial patterns of sediment storage in any river networ k. Finally, the paper considers the temporal changes to channel morphology in response to a human-induced pulse of sediment.