MANAGEMENT OF AN EMERGENCY EVACUATION: Introduction

INTRODUCTION   

After the earthquake occurred in the area of Modena and Bologna provinces (Emilia- Romagna region, Italy) the interest in planning an effective emergency management in evacuation has grown both for residential buildings and for industrial and commercial buildings.

At 4:03 a.m. of May, 20th, 2012, a seismic shock with a magnitude of 6.1 degrees on the Richter Scale occurred at 6.3 km depth in the area of Finale Emilia (Modena province) and it caused the death of 7 people, 4 of which were workers died under the collapse of recently constructed workshop. After that, another strong earthquake occurred at 9 a.m. of May, 29th, 2012 with epicenter between Medolla and Cavezzo (Modena province) with a magnitude of 5.8 on the Richter scale. Several aftershocks hit the area of Bologna, Modena and Ferrara provinces in the weeks after the first seismic event. The amount of the victims rose up to 27 two weeks after the second strong earthquake, and most of the death were workers. The earthquake caused serious damage: structure of historical significance collapsed, as well as lots of residential buildings, factories and firms. The damage of the earthquake was estimated to be of 13 billions and 273 millions of Euros. 

After this strong event that also deeply affects Emilia-Romagna’s economy, due to the high amount of victims between workers, the interest in build an effective emergency management in evacuation has grown both for business people and scholars.

In general, Italy is recognized as a seismic area because of its position between the African and Euroasiatic lithospheric plates. Nevertheless, Emilia-Romagna, and in particular the provinces in which the shocks occurred, is classified by the Italian National Institute of Geophysics and Volcanology as a low risk area. The most dangerous seismic areas in Italy are located in the center and in the south of the peninsula. The lack of physical exposure to earthquake has produced the lack of experience in people from Emilia-Romagna, so that they were not ready to manage the emergency.

Research in the field of building evacuation began in the first part of the last century and gained particular momentum since the last four decades (Bryan, 1999; Pauls & Jones, 1980). The first topics of interest have been the movement of people in corridors, on stairs and through doors, but also occupant density and travel speed (Kobes, Helsloot, de Vries & Post,

 

2010). On the basis of these studies the design and technological measures with which to ensure emergency safety in buildings are nowadays known and used. From the end of the 20th century, the study of evacuation from building become to be a field of study also for social sciences, and also a behavioral perspective was developed.

The empirical understanding of evacuation from buildings is complex and it requires a multi- disciplinary approach, so that several different research areas, such as mathematics, engineering, sociology and psychology are committed in this field of study. Most of the studies about emergency management and evacuation from buildings have focused primarily on calculating and predicting evacuation movements using engineering models, tools and computational simulations. Nevertheless, predicting occupants’ behavior is as important as designing buildings structures to develop a more safety evacuation plan. “Evacuation models are often used in the safety design process in the context of the performance-based design approach. They may be employed both to compare different safety designs as well as define the adequate egress strategies of a building” (Ronchi & Nillson, 2013, p. 6).

“Most of the evacuation simulation models that exist are based upon calculations in which the distance to exits, walking velocity and flow rate capacity of corridors, doors and stairs are decisive. This is the result of prior research, which predominantly focused on these aspects of evacuation. Few simulation models are based on human behavior in evacuation scenarios, such as the preferences for specific routes or exits, or the time needed to gather and interpret the information” (Kobes, et al., 2010, p. 4). 

Evacuation models measure evacuation performance by calculating how long it takes for occupants to evacuate a building. Muhdi (2006) has counted 28 different egress models based on the level of complexity in occupant behavior. Most of them are based upon calculations in which the distance to exits, walking velocity and the flow rate capacity of corridors, doors and stairs are decisive. Nevertheless they don’t consider all factors and processes related to human behavior. These models only calculate the time needed to perform each action of the evacuation process, for example standing up, queuing and reaching escape routes. This kind of approach simplifies too much the evacuation process (Kuligowski, 2008). “[…] we know that real evacuation decision making and movement is significantly more complex than water flowing in pipes or snooker balls rolling on a snooker table” (Shields & Proulx, 2000, p. 103). For example, most of the models that try to calculate the time needed to reach the emergency exit assuming that people immediately start evacuating after hearing the warning sound. This is an inaccurate belief and a minimalistic approach that ignores the cognitive, perceptual, psychological and social processes that are associated with evacuation movements, visual access, way-finding and spatial behavior of occupants. Indeed, people need time to understand if the sound they are hearing is really the alarm sound, These models, moreover, don’t consider the pre-evacuation period, that is labeled as “the period from the point when the occupant is notified that there is something wrong until he begins to travel an evacuation route out of the building” (Kuligowski, 2008, p. 7). In that period of time, which occurs before starting evacuation, people interpret the situation and assess the risk. Other models, in addiction, attempt to estimate the number of emergency exit needed according to the structure of the building or the occupants’ number. Such models don’t consider results from previous psychological researches, for example the fact that people under stress tend to choose the same exit used to enter the building (Kobes, Helsloot, de Vries & Post, 2010). Another psychological factor that these models neglect is, for instance, that it is not the actual length of an escape route which determines which way out of a building is chosen, but how it is perceived by the occupants (Kobes et al., 2010). 

Luckily, things are changing: “it is now recognized that evacuees are thinking and feeling beings, which react according to factors associated with the past, present and future, and can respond in a multitude of ways to the same incident, either independently or collectively with others” (Schmidt & Galea, 2013, p.12). A comprehensive model of evacuation should be able to predict individual behavior but also group dynamics that are likely to occur during an emergency. Leadership is one of such group dynamics that still has to be investigated to understand his role in emergency management. Some findings in previous researches have demonstrated that it plays a key role accelerating the time needed to evacuate (Gershon, Qureshi, Rubin & Raveis, 2007) or helping other occupants in the interpretation of the situation (Kuligowski, 2008). Nevertheless, other studies are needed in order to identify how the leader should manage the situation, which skills he/she should have, and how the communication leader-members shuld be. What it’s clear is that a leader could be an important resource for an effective emergency management.  

 

 

 

 

©  – MANAGEMENT OF AN EMERGENCY EVACUATION: A LEADER’S PERSPECTIVE – Sara Colangeli