Landscapes of the Lake Eyre Basin: the catchment-scale context that creates fluvial diversity

Abstract

Lake Eyre Basin (LEB) rivers are important but under-researched. This study integrates published and new information into a systematic geomorphological overview, subdividing the LEB into nine landscape zones: basin-margin Uplands with relatively high-energy rivers; Rocky Fringe, piedmont with short rivers and floodouts; Western Rivers, notable for neotectonism and stream capture; low-relief Northern Plains drainages and floodouts; Central Plains dunefield; Channel Country-Vertic Downs, cracking-clay interfluves and valley macrochannels; Channel Country-Stony Domes, rocky or sandy interfluves and complex macrochannels; Lakes & Dunes maintained by saline groundwater; and playas in the Mega-lakes. Zone boundary GIS datasets are available. LEB rivers are shown to be diverse and distinctive, indicating a need for locally relevant knowledge in management and monitoring. Fluvial landform suites include sand-bed rivers, macrochannels hosting coexisting anabranching and anastomosing systems in vertic floodplains, floodouts, low-angle alluvial fans, and three types of waterhole. Channels may be discontinuous or not present; floodplains can dominate flow transmission. Contributing hillslopes are heterogenous in their capacity to generate runoff, while drainage networks may have low to high degrees of integration. Management implications include the importance of in-river terrestrial ecosystems and “patchy” drainage networks, and the inapplicability of some morphometric practices.