Understanding historical channel change: Channel stability and instability in south eastern Australia and their causes P. Rustomji

Understanding historical channel change: Channel stability and instability in south eastern Australia and their causes

P. Rustomji

This project is concerned with the characterisation of the variety of river settings in south eastern Australia, in an attempt to better understand and interpret changes in river channel morphology over historical times. Digital terrain models are used to analyse catchment morphology of some fifty river basins. Similarly, analyses of stream flow records have revealed differences in the hydrological behaviour of the same rivers including measures of flood variability and runoff generation rates. Results indicate that there exists a previously unrecognised degree of variability in the hydrologic behaviour of different river basins, which influence channel morphology and its sensitivity to extreme events. A fieldwork program has commenced, where surveys of channel morphology, collection of river bed and bank sediments plus assessment of riparian vegetation levels is being undertaken. Linked with historical and geomorphologic evidence for channel instability and change, this program aims to determine the catchment variables that control sensitivity of a river to extreme events.