Power WL, Boersen K, Thomas K-L, Tilley L, Hudson-Doyle EE, Kaiser LH, Lukovic B, Heron DW, Wilson TM, Leonard GS, Johnston DM. 2019. Quicker and safer tsunami evacuations through agent-based modelling. Lower Hutt (NZ): GNS Science. 59 p. (GNS Science miscellaneous series; 134). doi:10.21420/9H4N-TH30.
All of Aotearoa New Zealand’s coastline is at risk of tsunami from local sources, those that reach the coast in less than one hour. Some areas in New Zealand are particularly vulnerable to tsunami, given the long distances to safety, and if a tsunami were to occur there may be large numbers of casualties. The primary means for saving lives is to educate the public to immediately self-evacuate tsunami-prone areas if they feel a long or strong earthquake: “Long or strong, get gone!”. In densely populated urban areas, Civil Defence and Emergency Management (CDEM) encourage people to evacuate on foot if they can. Mass evacuations pose many problems, as typically the urban infrastructure is not designed to handle such large volumes of pedestrians. In rural areas, these problems can be identified using ‘tsunami evacuation hīkoi’ exercises, where the community evacuates as if a large earthquake has occurred. This is not practical in towns and cities with thousands of residents or workers, and therefore modelling can be used to evaluate evacuation routes. In this project we have developed a computer model of people evacuating on foot and have applied this model to Petone (Lower Hutt), Napier, and Sumner (Christchurch). In each of these locations, two community workshops were held to receive feedback from the public about how to improve the models and improve evacuation speed and safety. Ideas received from the public and discussions with local CDEM representatives were used to produce recommendations to make tsunami evacuations quicker and safer in the future. Final results have been presented back to the communities in Petone and Napier (Sumner still pending). (auth)