Implementing notification strategies in the urbanEXODUS large-scale evacuation model

Abstract

A key consideration during a large-scale incident that affects a community, is how and when to notify the population regarding what protective actions to take. The effectiveness of a notification method is dependent on many factors, such as the medium used, message content, repetition frequency and target area. Therefore, choosing the optimal warning system, or a combination of them, necessitates careful consideration of these factors. Typically, evacuation models do not represent or consider the notification procedures explicitly and hence cannot determine how the specifics of a given notification method, or a combination of them, may affect the evacuation process. Large-scale evacuation tools incorporate the authorities’ notification procedures implicitly by incorporating their effect by increasing the duration of the agents’ response phase. In this work a framework is outlined that allows for the specification of notification methods to be defined within an evacuation model, considering parameters such as the notifications’ initial success rate, their subsequent success rates, in conjunction with time dependent notification areas and a percentage coverage. Using these parameters, a method is outlined that is flexible enough to cover a wide range of notification techniques, from mass notification systems such as location-based SMS and auto diallers, to area specific personnel-based systems, such as door-knocking or mobile loud hailer systems. The proposed notification model is incorporated into the urbanEXODUS large-scale simulation tool and demonstrated through a practical application during an actual tabletop exercise. The study found that incorporating notification procedures in an evacuation model has the potential to aid emergency managers in assessing the outcomes of different notification strategies. The innovation relates to a methodology that enables subject matter experts, such as emergency practitioners, to define notification response profiles within evacuation models. Furthermore, a novel approach for visually summarizing and presenting the simulation results related to the notification scenario and evacuation outcomes has been developed to facilitate communication to a wider audience.