Researching Crisis and Security Management (8910SSJ02)
Summary
Summary Crisis and security management readings week 6
17 views 2 purchases
Course
Researching Crisis and Security Management (8910SSJ02)
Institution
Universiteit Leiden (UL)
Bernardini, G., Quagliarini, E., 2021. Terrorist acts and pedestrians’ behaviours: First insights on European contexts for evacuation modelling. Safety Science 143, 105405.
Bernardini, G., Finizio, F., Postacchini, M., Quagliarini, E., 2021. Assessing the flood risk to evacuees in outdoor bui...
Researching Crisis and Security Management (8910SSJ02)
All documents for this subject (9)
Seller
Follow
Hebe
Reviews received
Content preview
Bernardini, G., Quagliarini, E., 2021. Terrorist acts and pedestrians’ behaviours: First insights on
European contexts for evacuation modelling. Safety Science 143, 105405.
Terrorist acts in the Built Environment (BE) are characterized by interactions between the
attackers, the exposed pedestrians and the BE itself. The analysis of real evacuation events
by videotapes allows researchers to have a potentially unbiased data source to this aim.
This research provides one of the first and wide databases of pedestrians’ behaviours in
terrorist acts, focusing on different characteristics of the BE (e.g. indoor and outdoor;
obstacles presence; safety management) and of the terrorist acts (e.g. type of attack;
proximity between the pedestrians and the trigger).
Since the analysis on how people behave in emergency conditions due to terrorist acts is still
limited, efforts to provide reliable (qualitative and quantitative) databases on such issue is
urgently needed and should especially take advantages of real-world events.
Firstly, videotapes of real-world emergencies due to terrorist acts were collected in a
database and each of them was divided into specific “scenes”. Then, qualitative analyses
were performed to detect emergency behaviours and assess their activation frequency as
well as the BE conditions that could induce their activation. Finally, quantitative analyses on
motion speeds were carried out to assess the pedestrians’ instantaneous evacuation speeds
and the fundamental diagrams
“Scenes” with deleted frames, inadequate illuminance or excessive camera movements were
removed from the database. “Scenes” from fixed cameras were preferred for quantitative
analysis. When the framing quality of these scenes allowed continuously tracking individuals’
motion over time, manual tracking methods for quantitative analysis were applied. The
manual method for tracking pedestrians’ motion in evacuation conditions was chosen,
because of the videotape’s characteristics (such as the not uniform backgrounds or the
resolution of the images).
65% of the “scenes” refers to videotapes from mobile cameras . 59 pedestrians were
randomly selected between those who could be tracked for a significant time in the “scene”,
i.e. some seconds or more. Basics statistics were also provided on the average speeds of the
traced individuals over the analysis time.
The videotape analysis highlights that no direct action by the supposed terrorists was noticed
by the crowd. In fact, the crowd simultaneously started to evacuate after having seen the
motion of a restricted group of pedestrians, without perceiving any other sign about the real
presence of a risk (phantom panic). When the pedestrians’ density increases, a significant
reduction in motion speed is noticed.
Despite the limitations due to the current sample dimension, quantitative results also remark
how researchers and safety designers should be discouraged from using general-purpose
databases. The main differences among data could be referred to different factors related to
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Hebe. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.87. You're not tied to anything after your purchase.
