The simulation of urban-scale evacuation scenarios: Swinley forest fire

Forest fires are an annual occurrence in many parts of the world causing evacuation of nearby residential areas and industrial facilities. The frequent occurrence of these events deems it necessary to develop appropriate evacuation plans for areas that are susceptible to forest fires. A well-established and well-validated evacuation model, buildingEXODUS, has been extended to model large scale urban/rural evacuations by including the road network and open spaces (e.g. parks, green spaces and town squares)along with buildings. The evacuation simulation results have been coupled with the results of a forest fire spread model and applied to the Swinley forest fire. Four evacuation procedures differing in the routes taken by the pedestrians were simulated and analysed providing key evacuation statistics such as time to reach the assembly location, the distance travelled and congestion experienced by the agents. In addition, the safety margins associated with using each evacuation route are identified. This is the time available between the safe passage of the pedestrians through the route and the route being considered no longer safe for pedestrian use. A key finding of this work is the importance of formulating evacuation procedures in response to wildfires by providing occupants timely evacuation notice and appropriate choice of routes to keep them at a safe distance from the fire even at the cost of taking longer evacuation routes.