Jane Cawson
Department of Forest and Ecosystem Science
The University of Melbourne
Level 1, 221 Bouverie St, Parkville
VIC, 3010, Australia
Email: j.cawson@pgrad.unimelb.edu.au
Degree
PhD
Thesis title
Connectivity of runoff and erosion following planned burns in dry eucalypt forests
Supervisors
Dr Patrick Lane
Dr Gary Sheridan
Project Outline
Wildfires are known to impact on water quality as a result of increased runoff and erosion. Planned burning is one way of minimising this risk of wildfire. As wildfires have become more prolific in Victoria, targets for planned burning have grown. Despite the common occurrence of planned burning, little is known about its effects on the potential for runoff and erosion. Understanding how planned burning may affect water quality is especially important when burning is conducted in catchments that supply drinking water or have important aquatic biodiversity values.
A key characteristic of planned burns is their patchiness. A range of severities and unburnt areas often occur within a single burn. This poses some challenges for predicting post-fire runoff and erosion. Firstly the potential for runoff and erosion is likely to be different for each fire severity class. Secondly, the amount of runoff and erosion that reaches a gully is likely to depend on the spatial arrangement of the fire severity patches. A further challenge is that the usual measures of fire severity may not translate directly to soil impacts.
This study aims to better understand the potential risk posed by planned burning to water quality. The overall hypothesis is that water quality impacts from a planned fire can be estimated by predicting the likelihood of runoff connectivity between burnt patches and streams.
The objectives of the study are:
- To define fire severity in relation to fire induced changes to soil properties
- To quantify the runoff and erosion characteristics of each soil fire severity class within a range of soil types and at various times since fire
- To model runoff connectivity at the hillslope scale for different times since fire and rainfall intensities
- To better understand spatial patterns of soil fire severity following planned fire
- To assess the relative risk to water quality of various spatial arrangements of fire severity using a runoff connectivity model
Link to Postgraduate index page