This research has developed a new model for estimating flood risk. Photo: NSW State Emergency Service.
A rapid assessment of flood risk has been long needed in regional NSW, and Hazard Note 52 details a LiDAR-based flood model that has been developed to better understand how flooding evolves during a storm. Its application will help overcome a national void in vital information about flood risk, and help NSW SES prevent, plan and respond to the time-varying exposure of flooding over large areas.
Researchers used the 1986 flood in the Hawkesbury-Nepean catchment in western Sydney as a case study to test the river system model, and found that flooding can occur in different places and at different times during a storm. This data was then used to examine the time delay between rainfall and flooding and how that can lead to staggered flooding.
This model will assist agencies to create a simplified and large-scale assessment of flood risk based on rainfall, physical catchment properties and exposure information.
Further reading
Mortlock TR (2017) Event-based modelling of flood hazards and impacts during extreme east coast low storms utilising a rapid, regional-scale approach, Bushfire and Natural Hazard CRC