Dryland Channel Forms and Processes: A Whole Catchment Scale Study of the Diamantina River, Central Australia

Abstract

Many aspects of dryland river research, such as channel forms and processes, remain poorly investigated at the catchment scale because of the practical difficulties and costs of carrying out fieldwork in remote dryland regions. Remote sensing techniques, including Shuttle Radar Topography Mission (SRTM) data, and modelling are partly overcoming these difficulties. This study has used fieldwork, remote sensing and computational modelling to investigate channel forms and processes along the Diamantina River at the catchment scale, a large dryland river in the Lake Eyre Basin, Australia. It focuses on comparing the fluvial morphology and hydrological characteristics associated with selected (dominant) channel forms with the primary anastomosing, meandering, anabranch and braided channel forms of the Diamantina River receiving particular attention. The Diamantina River is comprised of a channelised inner floodplain (IFP), bounded by a non-channelised outer floodplain (OFP). Channel forms within the IFP were found to be significantly different in terms of their; sediment size, cross-sectional geometry, and channel form pattern both laterally and in the downstream direction.