The Challenges of Modelling Ungauged Urban Catchments
The latest revision of Australian Rainfall and Runoff (ARR) has updated guidance for flood modelling in urban catchments. As most urban catchments are ungauged, we have traditionally used the rational method to estimate the runoff.
With advances in flood modelling techniques, including detailed two dimensional models with rainfall applied to the grid, have we been able to improve our runoff estimates? Can we use other types of data for verifying our models? How do we treat rainfall losses in a hydraulic model compared to a traditional rainfall-runoff model? And are we finally able to move on from the rational method, or is it still the best estimate we have?
This talk will use case studies from ungauged urban catchments to illustrate the challenges these models entail, discussing some innovative approaches, lessons learnt, and implications for practitioners using the ARR revision.
About the Speaker
Luke Cunningham MIEAust CPEng RPEQ, Principal Engineer Group Manager – Integrated Stormwater Management
Luke is an Environmental Engineer who specialises in hydrologic and hydraulic modelling of urban stormwater networks and overland flow paths as well as water quality improvement investigations. Luke joined Water Technology in 2009 and has primarily worked on complex linked one and two dimensional urban flood modelling projects. Prior to joining the team at Water Technology, Luke worked in Melbourne Water’s Flood Mapping and Mitigation Team where he focused on the impacts of urbanisation in metropolitan catchments.