Cyclone surge and mass evacuation route issues in Cairns, Australia

Mass evacuations will be necessary from low-lying areas of Cairns, Far North Queensland, Australia, ahead of a threatening cyclone surge. Aiming to minimise lost of life through drowning in extreme inundation events over closely populated areas, developed research methods and recommendations are given. Public knowledge, precautionary evacuations and a flooded road network are central to safety. A detailed research process of mass evacuation issues in Cairns in the mid 1990s is contrasted with a 2005 review of preparedness.\ud \ud Modelling predicts a maximum surge height of 5 metres, defining evacuation and 'safety' zones. A 5-metre mound of highly agitated seawater and smashing debris would inundate\ud about half of Cairns. Three surge levels were defined, then the 'temporary coastlines' of a 1, 2 and 5 metre surge were mapped from digital elevation data. The worst surge, combined with escaping floodwaters, will directly threaten more than 70,000 people, all needing safe shelter.\ud \ud Widespread rains preceding the cyclone are likely to make most Cairns exit roads impassable to urban traffic, possibly days before cyclone landfall. Working with road engineers and planners, flood points in the road network were identified and mapped, thus defining 'safe' exit routes.\ud \ud Recommendations include full public knowledge of the risk, via displays in shops and shopping centres, so residents and tourists can assess their risk as the cyclone season\ud approaches, and are prepared to act if threatened.\ud \ud Early, precautionary 'self' evacuation to private billets is advocated, in line with social sustainability principles, acknowledging the merit of precautionary evacuation as practice. Local authorities now advise people: 'Know friends in high places'. Methodological\ud development, mapping and recommendations are given. This is to empower and motivate an informed and prepared community to move early, taking responsibility for their own and\ud others' safety, and responding to extreme but knowable threats of catastrophic natural disaster. The explored approaches can be generalised to other situations of like vulnerability, such as tsunamis.\u