Water contamination risks associated with a combination of planned and unplanned fire in south eastern Australia

Friday, 19 December 2014
Petter Nyman1, Gary J Sheridan1, Christoph Langhans2, Philip J Noske2 and Patrick N J Lane2, (1)University of Melbourne, Parkville, VIC, Australia, (2)University of Melbourne, Parkville, Australia
Planned burning reduces fuel loads in forests, potentially reducing the severity of subsequent wildfires. However planned burning also increases the risk of a significant water quality impact by maintaining a proportion of the catchment in a burnt condition conducive to generating high magnitude erosion events (eg. debris flows). Differences in the frequency and magnitude of planned and unplanned fire, combined with poorly understood relationships between fire severity and hydrologic impacts, means that predictions of the net water contamination risks associated with any particular fire regime are difficult to predict. This presentation synthesises results from 10 years of point, plot and catchment-scale post-fire hydrology and erosion studies in SE Australia to estimate the likely benifits and risks of planned burning scenarios from a drinking water supply perspective