AFAC25 NSW tsunami inundation modelling project
NSW SES’s existing tsunami evacuation mapping has been publicly available since 2016 and defines a conservative evacuation zone covering areas with elevation less than 10m, within 1km of the coast and 10km up estuaries. Based on this mapping, a tsunami land threat occurring today would require evacuation of approximately 1.1 million people across NSW. This would pose a significant challenge to NSW SES and other emergency agencies, who would be quickly overwhelmed.
By Nicholas Kuster, NSW State Emergency Service
NSW SES’s existing tsunami evacuation mapping has been publicly available since 2016 and defines a conservative evacuation zone covering areas with elevation less than 10m, within 1km of the coast and 10km up estuaries. Based on this mapping, a tsunami land threat occurring today would require evacuation of approximately 1.1 million people across NSW. This would pose a significant challenge to NSW SES and other emergency agencies, who would be quickly overwhelmed.
The current mapping lacks the nuance that can be obtained by using hydrodynamic models to capture tsunami interactions with the local landscape. To address this gap, NSW SES partnered with Geoscience Australia to undertake an 18-month collaborative project to develop broadscale tsunami inundation maps for the entire NSW coast, including Lord Howe Island. For the first time, supercomputing has enabled tsunami inundation to be modelled for the entire NSW Coastline, using a Monte Carlo approach to capture the hazard from a range of subduction zone earthquake sources. The results are translated into mapped zones that correspond to tsunami threat categories issued by the Joint Australian Tsunami Warning Centre i.e. “No threat”, “Marine warning”, and “Land warning”.
These inundation maps will form the basis of NSW SES’s tsunami preparedness and planning, operational response arrangements, and publicly available interactive tsunami risk and evacuation maps. The data will be incorporated into mapping and intelligence systems and the development of consequence information which will inform more localised tsunami emergency plans, community education/awareness programs and operational planning.
The Department of Fire and Emergency Services and Queensland Fire Service are both working with Geoscience Australia on separate projects to develop inundation mapping for areas within their respective States. NSW SES have been collaborating with these agencies to share knowledge and build consistency with the development of tsunami preparedness and response capability within Australia.