Prioritising flood risk investment and infrastructure in Queensland

Abstract

In 2012 the first Queensland-wide flood map was developed by an international team studying world-wide flood risk. This was taken over in 2018 by a team in Australia who incorporated updated Bureau of Meteorology Intensity-Frequency-Duration datasets, the information within the ARR DataHub, and now Geoscience Australia 5m topography. In 2020 this information was used to re-map Queensland, covering the entire South-East corner (from Gold Coast to Noosa, extending to the Great Dividing Range) and Northern QLD (from Cook to Mareeba and Cairns) at a 5m resolution and the remaining state at 30m resolution. The detailed modelling was undertaken at 5m resolution for six return periods, and covers every creek, river and watercourse in the region. The approach behind this modelling was not that of a typical flood study – instead adopting methods used within catastrophe modelling for the insurance industry. National, continental and global-scale flood risk mapping is not a new concept, with a number of approaches developed by organisations working internationally. But in a world where ongoing natural disasters and the impacts of climate change are becoming more prevalent, the speed of technological improvements used within these large-scale assessments are now challenging local-scale mapping. These maps have now been used to perform a State Wide risk assessment, identifying high risk areas prone to flooding, and supporting Councils in prioritising their investment in flood infrastructure