European Cities Prone to Terrorist Threats: Phenomenological Analysis of Historical Events towards Risk Matrices and an Early Parameterization of Urban Built Environment Outdoor Areas
- A detailed background of terrorist threats and their relations with UBEOAs (Section 2).
- The identification of tools for the phenomenological analysis of terrorism in European cities and UBEOAs (Section 3).
- The analysis and the discussion of the terrorist phenomenon with a double level of detail (UBE and UBEOAs) for the creation of associated matrixes of risk (Section 4).
- For UBEOAs, an early parametrization of elements involved in the threat. Here, all the elements and features of UBEOAs are involved in the risk assessment according to the risk determinant (Hazard, Vulnerability and Exposure) (Section 5). This is a preliminary reading of UBEs for the future determination of their risk assessment.
- The discussion of the results and conclusions (Section 6).
2. Background of the Relevance of Terrorist Threats and Urban Built Environment Outdoor Areas in Risk Exposure
- Active actions aimed at creating a bi-univocal relation between overarching governances and urban users (e.g., intelligence activities, surveillance).
3. Methods and Tools
- Determine the inherent classes of risk for UBEOAs in Europe as a first phenomenological analysis of terrorism based on the assessment of direct comparison with other classes of uses for the UBE.
- Understand the relevance of specific uses in UBEOAs that may change the risk classes of such UBE.
- Identify the most “efficient” combination of Attack Types and classes of uses in UBEOAs.
- Determine the parameters involved in the risk assessment for the most efficient combination identified for UBEOAs.
- The determination of risk matrices related to terrorist threat results from the study of the events catalogued in the GTD in the western Europe UBE and UBEOAs. Here, the phenomenological analysis follows a double level: firstly (Section 4.1) (i) the categorization of the events in European UBE, which occurred 1999–2018 (GTDOccEur), according to Environmental Classes (ECs), as recurrent UBE for uses and types, and Attack Types (ATs) and (ii) the qualification of events according to the frequencies and consequences of each ECs-ATs combination. This highlights the most relevant ECs exposed to the events. The second level of analysis (Section 4.2) considers the same procedure for the reduced GTD sample, where only attacks occurring outside the most relevant ECs (UBEOAs) are considered (GTDOccEurOut). Thus, the selected events are studied in order to (i) categorize the events in the reduced sample, as couples of selected Outdoor Environmental Classes (OutECs) and Attack Types (ATs) and (ii) to qualify the matrix of risk according to the frequencies and consequences of each OutECs-ATs combination. Both levels are functional in identifying two risk matrixes for the rapid assessment of the Terroristic Risk Levels in Europe and the most exposed UBEOAs, as a direct combination of AT and ECs/OutECs (Section 4.3).
- The parameterization of elements influencing the Determinant of Risk (Vulnerability, Hazard and Exposure) in the most hazardous risk classes (OutdoorEC; AT). In this phase, the main national and European instruments used to manage the terrorist threat are analyzed to highlight which morpho-constitutive elements influence the risk, mainly organized in a short index of representativeness (Section 5). Here, the process combines the results of the phenomenological analysis on UBEOAs (Section 4.3), the European experiences in managing terrorist threat and the principles of the phenomenon (TPs), previously identified in Table 1.
4. The Phenomenological Analysis of Terrorism in Urban Built Environment Outdoor Areas in Western Europe
4.1. Categorization of Terrorist Events in European Urban Built Environment
- The Attack Types (ATs), following the classification process of GTD as “weapon information”, recoding them with the Tn code.
- The Environmental Classes (ECs), using a process of recoding the “Target/Victim information” variable (section vi, ). In this case, six Environmental Classes (defined with a Capital letter) are introduced for the parametrization of targets, considering the potential crowd levels (impact Factor criteria), the political/religious meaningfulness of urban spaces (Publicity impact Criteria), the existing security and checking systems (impact factor on micro/macro terror) and the Built Environment typology (Outdoor area/building).
4.2. Categorization of Terroristic Events in European Urban Built Environment Outdoor Areas
4.3. Results on the Phenomenological Analysis of Terrorist Threat in Western Europe—The Matrixes of Risk for the Built Environment and Related Outdoor Areas
- Outdoor areas (F class) are featured by low-risk exposure both for T2 (Armed Assault) and T3 (Bombing/Explosion) Attack Types. However, T2 relevance depends on the high probability of the attack occurring, while T3 relates to the higher impact of consequences. The case in Barcelona (Ramblas) on 17 August 2017 is the most representative case of F/T2 combination in Western Europe.
- Environmental B Class represents the most exposed one. Both T2 and T3 risk levels are higher than outdoor areas (F) emphasizing high likelihood and consequence levels, respectively. B class includes all the public buildings (pubs, museums, etc.) in which human activities related to amusement take place, and which are usually featured by low levels of control. In B/T2 combination, the peculiar case is the Bataclan Attack that occurred in Paris on 13 November 2015.
- Moreover, the D class (representative or strategic buildings) represents a medium combination. Focusing on the D-T3 combination, it is representative that all the attacks by trucks or cars aimed at acquiring a symbolic or strategic meaning; however, according to the relevance highlighted in consequences and likelihood, it appears relevant for the real position of events that usually are linked to the external area of buildings.
- Finally, the A class—including airports and rail stations—is the most exposed class due to its high probability for the presence of crowds. However, the relevant security system moves the A class in the Macro-terror classes of attacks, in line with actual processes of security management for these places.
- All the UBEOAs included in F and FB are more exposed than FD (strategic and symbolic ones) due to their different “protection and security systems”, moving perpetrators through the first two as a minor resistant line (TP.3).
- The relevance of T7 in strategic and symbolic areas reflects the symbolic relevance of FD, where the attack aims at the milieu (TP.2).
- From a wider perspective, as the most frequent attacks, T2 and T3 reflect the principle that describes the choice of weapon (TP.4).
- UBEOAs are prone to terrorist attacks due to the high probability of crowding (TP.3—soft targets).
- T2 and T3 represent the most used Attack Types (TP.1—micro-terror) and they generate the highest levels of impact.
- The maximization of impact is highlighted for the FB class. Differently from FD featured by a higher level of openness—inherent to the necessity to guarantee visibility—the presence of obstacles in FB can reduce the capacity of escape (TP.3—soft targets).
5. The Parametrization of Elements in Urban Built Environment Outdoor Areas Influencing Vulnerability, Hazard and Exposure in the MOST Hazardous Risk Classes
- “hazard” usually refers to “the possible, future occurrence of natural or human-induced physical events that may have adverse effects on vulnerable and exposed elements”. If the feature of the “return period” is usually associated with natural events, for terrorism risk, it is necessary to focus on the capacity of the perpetrator to be “attracted” toward the analyzed places and “moved” by specific motivations.
- “vulnerability” refers to “the propensity of exposed elements such as human beings, their livelihoods, and assets to suffer adverse effects when impacted by hazard events”. Due to these features, vulnerability to terrorism of places should consider all the elements of UBEOAs that can support or represent specific weaknesses.
- “exposure” is related to the “impact” concept. IPCC suggests that exposure refers to “the inventory of elements in an area in which hazard events may occur”. In the case of the terrorist threat, exposure refers to human security, correlating with specific features or elements that could increase the number of people involved in the events, or the maximization of victims.
|Physical Element of BE||Position or Association of Element/Feature in BE—F (Frontier)/I (Inside)|
|TARGET||T1||TP.3; TP.3.2||Inter-dependence and replacement of targets; soft target||||H|
|T1||TP.2||Publicity impact is key to targeting||||H|
|T2||Each EC has an inherent probability to be a target due to the relevance to be a soft target||Section 4||H|
|T3||Symbolic value of the target; presence of media||Section 4||H||F/I|
|T2||The potential high level of crowd of EC increases the likelihood of hazard||Section 4||H||F/I|
|T3||People gathered in one place||||H|
|T3||The level of alert could consider the attraction of places for tourists that can increase crowding||||H|
|T2||TP.4||The characterization of terrorist weaponry||Section 4||H|
|T3||Security personnel, the presence of the police force||||H||X||F/I|
|T3||The introduction of countermeasures can prevent the access of vehicles||[50,51]||H||X||F/I|
|T3||Study strategies for controlling accesses||[49,52]||H||F|
|FORM/SHAPE||T3||The presence of speed regulation elements limits the speed of vehicles along the street||[50,51]||V||F|
|ACCESSIBILITY||T3||The local topography of the place can preclude the vehicle-borne threats||||V||F/I|
|T3||Mitigative measures should be correctly designed to be effective||||V||F/I|
|T3||Management of the vehicular traffic||[52,54]||V||F|
|OBSTACLES||T1||TP.3.2||Soft target, not only as a place but also as a part of the place that allows high crowd levels (i.e., archaeological sites, stairs)||||V||I|
|T2||Most of the “attractor” classes also have a high crowd level outside the buildings (FD-FB) (i.e., Dehors)||Section 4||V||X||F/I|
|T3||The presence of mobile of fixed obstacles as specific attractors for people (rendezvous, hangouts)||||V||X||F/I|
|ATTACK TYPE||T2||Inherent capacity of attack to maximize the effects||Section 4||E||F/I|
|T3||Study different strategies relating possible Attack Types||[49,52]||E||F/I|
|CROWD||T1||TP.1||The impact factor||||E||F/I|
|T2||The high level of crowding in some ECs influences the total number of victims||Section 4||E||F/I|
|T3||Check the variability of density in some part of the places||||E||F/I|
|REACTION/OBSTACLE||T3||Use urban furniture or urban object as protection during the attack||[55,56,57]||E||X||F/I|
|T3||Check the access and emergency paths and their capacity to be crossed during the evacuation||[52,56,57]||E||X||F/I|
|T3||Check for the presence of obstacles in the access points||||E||X||F|
|T2||All the protective obstacles should be analyzed in terms of efficacy for each Attack Type||Section 4||E||X||F/I|
- [H_I.1] Index of targets (iTRG): each ECs has an inherent probability to be attacked, as demonstrated in previous sections (in terms of relevance in likelihood for B and D classes of ECs and consequently for FB, FD and F OutECs) (T2—Section 4). Here, the “environmental” relevance of the place depends on the inherent likelihood to be attacked, as a consequence of “Soft Target” significance (TP.3.2). The dimension of the target cannot exclude the symbolic relevance of Outdoor Areas. In fact, even if the previous assessment of the terrorist phenomenon follows a geographic independent analysis, the choice of Outdoor Areas should be related to the religious, political and economic relevance (e.g., Navigli in Milan, Ramblas in Barcelona). For them, the concept derives from the “Inter-dependence and replacement of targets” as included in TP.3 for the case of “soft targets”, while the presence of representative and symbolic buildings included in B or D ECs can influence the “Publicity impact” (TP.2).
- [H_I.2] Index for uses of BE (iUSE): according to the necessity to “maximise” the effect of violent acts, the use of Outdoor Areas and their buildings likely has different relevance (TP.1). It is also in line with the results of the assessment of the phenomenon according to which the high level of crowding affects the “attractiveness” of places for the choice of place by perpetrators (T2—Section 4) . As a close dependent property of the previous index, the representativeness of a place, also for the presence of cultural and historical sites, highlighted how the “cultural” or “touristic” use of places may influence the total amount of people in a place . In this sense, the index of use reflects the variety of crowding levels in Outdoor Areas as a consequence of touristic fluxes and consequent specific activities and, thus, should be date/time dependent.
- [H_I.3] Index of prevention (iPREV): according to the current significance of terrorism in cities, the high level of countermeasures or mitigative solutions can influence the potential likelihood of the threat for Outdoor Areas; this is because of the difference between hard and soft targets (TP3). Similarly, the protection systems could vary in terms of weaponry—the Attack Type—used to reach the violent goal (TP4). In this case, the index describes both the presence of preventative solutions in the urban BE (e.g., access control, heavy barriers) and the capacity to be efficient in the specific Attack Type (e.g., vehicles or cold steel) [48,49,50,51,52]. Here, all urban physical elements defined as mitigative, as well as geometric features of accesses, could be included in the assessment . Due to that, in this index, we included all the physical elements included in the Outdoor Areas, as well as along the frontier.
- [V_I.1] The form of spaces (iSHP), referring to the plan and geometric features of Outdoor Areas, as well as its morphological structure. In detail, focusing on two main shapes of spaces, compact or elongated shapes can influence the Attack Type effect. In fact, an armed assault has major effectiveness for compact shapes compared to elongated ones; on the contrary, an elongated space facilitates the attack by vehicles, because of the direct relation between acceleration and space [51,53]. Similar relations can be associated in the case of bombing attacks, considering car bombs parked or bomb packages. This index should consider the geometrical features of Outdoor Areas, as well as external areas of specific attractors (e.g., for the presence of ramps outside buildings), that may influence the vulnerability of the place.
- [V_I.2] The accessibility level of the urban outdoor area (iACC): the descriptor considers both physical and conditioning features along the perimeters of Outdoor Areas, mainly focusing on access. In fact, an Outdoor Areas featured by a very high permeability level (e.g., fragmented built frontier for the presence of several streets coming in the Outdoor Areas) both for people and vehicles increase a place’s average vulnerability to attacks . In this sense, the characterization of accesses for this index should be related to the geometric features, as well as to the management of accesses [52,54]. Considering the accesses as a physical part of Outdoor Areas, main features to consider include the width of accesses, the presence of specific urban furniture that reduces the width, or the local topographic features of the accesses that influence the accessibility (i.e., stairs) . The traffic limitation constitutes an overordered system of vulnerability reduction, even if only referred to the frontier properties. In fact, all the previous features can also be associated with physical BE objects within the Outdoor Areas that limit or modify access to external areas of attractive buildings. The distance between flowerpots or benches constitutes an example. Finally, the Accessibility index has a prevalent relevance for all the attacks that involved vehicles.
- [V_I.3] The Obstacles (iOBS(V)): the descriptor refers to all the urban furniture inside the urban Outdoor Areas which affect the vulnerability level of the risk. Here, the obstacles refer to all the BE elements—furniture, geomorphological discontinuities (stairs); sights—fixed or temporal—that generate social meeting points (rendezvous, hangouts) , as well as cultural or touristic attractions (e.g., monuments, fountains). It is the case of dehors for restaurants or bar, staircases and benches, or green areas, as physical elements located both along the frontier or inside the Outdoor Areas. In this sense, the index includes the obstacles that may increase the vulnerability of the places as “soft targets” themselves (TP.3.2).
- [E_I.1] The Attack Type (iatt): this is the index related to the consequences levels (in terms of victims and injured persons) of the AT combined with the OutECs, according to the Statistic analysis in the previous section (T2, Section 4). This is also in line with the European suggestion in managing strategies for emergencies, suggesting studies where solutions should consider the possible Attack Types [49,52].
- [E_I.2] The crowd level in the Outdoor area (icrw): here, the index defines the potential impact in terms of victims and injured persons, and refers to the crowd classes (person/m2); here, the index is strictly related to the use of Outdoor Areas or external areas related to buildings uses, above all for B and D ECs resulting from the previous analysis (T2, Section 4). Unlike the index of use identified for H_I.2, the crowd level must be expressed as the potential density of people involved in the attacks. The relevance of building uses and relative external areas is referred to the concept of “Space of Relevance”: according to the positioning of access points inside the buildings and to their main uses, some external areas could be affected by different levels of crowding in a determined external area .
- [E_I.3] The attack reaction (iREA): the index refers to the inherent OutECs reaction for each Attack Type, considering the easy escape or protection levels for users, as well as the presence of countermeasures or urban furniture inside the area. In this sense, the “psychological” dimension of users is not considered, as well as their preparedness for the event. Obstacles are among the BE elements to be considered in this index. However, unlike the Vulnerability assessment, obstacles influence the impact in two ways; focusing on the European experience in educating citizens, the presence of objects can constitute a passive system of protection during the attack [55,56,57]. However, urban furniture is associated with an incrementing factor in exposure, when they constitute a system of obstacles along the evacuation paths [52,56,57]. Due to these features, obstacles located inside the outdoor areas should be considered not only for their geometric prevalent characters (height, diameters, etc.), but also for their inherent influence in protecting people from the attack (that depends on the type of attack itself) and in interfering with emergency paths and exits . Unlike protective systems along the frontiers of Outdoor Areas, which are usually standardized according to speed resistance against ramming vehicles, these obstacles are usually unqualified for resistance qualities but recognized only for their qualitative inherent capacity to protect people (the relevance of obstacles in protecting people derives mostly from the assessment of educative national initiatives in managing the emergency [56,58,59]). Likewise, the attack reaction index includes the presence of specific urban furniture that constitutes a physical countermeasure to terroristic attacks. As discussed for previous indexes, countermeasures should be assessed for the efficiency to specific Attack Type (T2, Section 4).
6. Discussion of Results and Conclusions
- The discussion of terrorist threat in real European outdoor areas of cities in order to discuss their potential risk exposure, as a consequence of the phenomenological analysis. Here, the significance of UBEOAs as “ordinary urban spaces” (B, D and F Environmental Classes) has been highlighted, showing the high relevance in likelihood (possible event, one event per week) and consequence (medium to extreme effects, 30 to more than 3000 people involved). In that sense, the parametrization of European events as couple of Attack Types and Environmental Classes allows understanding of the phenomenological threat to the identification of most recurrent and hitting ones.
- The assessment of UBEOAs risk exposure, relating them to the use of the most exposed function of buildings facing the outdoor areas and combining the weaponry types. For them, Armed Assault and Bombing/Explosion results are recognized as the most recurrent and the most efficient for the maximization of the effects. Moreover, the assessment of the phenomenon in the reduced sample has highlighted two major points of discussion: firstly, that T7, as adjunctive and more frequent AT in the whole sample, has minor relevance; then, that the severity of T2 and T3 Attack Types increases when the selected OutECs are considered. These elements can be argued considering the number of people involved. According to the necessity to maximize the effect, most T7 attacks take place in the inner part of ECs, where higher crowd levels can be found. On the other hand, the opportunity to study the phenomenon for outer parts of buildings remarks on people’s habit of staying outside public buildings for a long time, increasing the inherent vulnerability of certain places. This is also confirmed by the upgrading process from moderate, medium and major consequence levels to lower ones when OutEC/AT and EC/AT combinations are compared (Table 6 and Table 8).
- The creation of matrixes of risk is useful for the analysis of urban Environmental Classes combined with weaponry, as a smart and simplified tool for the first level of understanding for UBEOAs exposure to the hazard. Specifically for the work, matrices allow the identification of major efficient ATs and ECs coupled as a threat to focus on specific classes of ECs and OutECs. In fact, the lack of literature about such risk management in Europe means there is currently no way to determine which kind of threat (where and how) appears to be most relevant. From a more general point of view, the setup of the matrices constitutes the opportunity to provide a comprehensive overview of the European phenomenon, providing a smart and fast instrument for the comparative assessment of risk exposure in the whole city categorized in classes. Moreover, the use of matrices offers the opportunity to compare such risk to other ones already and fully discussed (e.g., seismic activity and flood risks).
- The parametrization of such urban areas in the most critical condition (Attack Types and functions), according to the main Risk Determinant (Hazard, Vulnerability, Exposure) and the physical elements in the BE. Here, the processes have highlighted the recurrence of inherent parameters involved in the phenomenological assessment, such as the Attack Type, the use of the places and buildings within the Outdoor Areas, as well as the symbology of the target. On the other hand, the main morphological and physical properties of the BE have emerged from the analysis, specifically:
- Obstacles, referring to all the elements that have a geometry and physical presence inside and along the frontier of the Outdoor Areas that can interfere with people (both users and perpetrators). Mitigative systems (i.e., barriers, traffic controllers) are part of such classes interfering with the increasing level of likelihood of the events; however, major relevance for the study is associated with the urban furniture (fixed or mobile) and monuments for their double effect on the inherent level of vulnerability of the place, as well as the variation in the exposure level when such elements can be identified as inherent protective systems for the users. In this sense, results have emphasized an opposite point of discussion, pointing out the necessity for analysis of the present urban obstacles to study their potential increasing or decreasing potential with regard to the risk (usually, obstacles have a negative effect on the path, mitigative elements positive on the risk reduction). As a complementary discussion, the presence of mitigative systems should be also studied for the possible interferences with other risks which involve mass escape.
- The geometric relevance of the places, as their quality to interfere with the total vulnerability level, above all when vehicle attacks are considered. The accesses and their morphological characters can represent an inherent barrier to terroristic events. On the other hand, the main morphological features of the place (e.g., compact or elongated) can influence the vulnerability, too. This is coherent with all the rapid traumatic events that generate fast evacuation processes (e.g., seismic activity, floods). Correlating obstacles to geometric relevance, the use of movable or fixed mitigation systems can support the management of people and the perception of places, in accordance with the discussed theory of “Security by design”.
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
|GTD||Global Terrorism Database.|
|OutEC||Outdoor Environment Class.|
|UBE||Urban Built Environment.|
|UBEOA||Urban Built Environment Outdoor Area.|
|EC||TARGET SUB-TYPES (GTD|
|B||Private Security Company/Firm|
|N||Politician or Political Party Movement/Meeting/Rally|
|N||Head of State|
|N||Government Personnel (excluding police, military)|
|D||Police Buildings (Headquarters/Stations/School)|
|D||Police Patrol (including vehicles and convoys)|
|N||Police Security Forces/Officers|
|D||Military Recruiting Station/Academy|
|N||Military Personnel (soldiers, troops, officers, forces)|
|D||Military Transportation/Vehicle (excluding convoys)|
|N||North Atlantic Treaty Organization (NATO) Related|
|Airports and Aircraft|
|A||Aircraft (not at an airport)|
|N||Diplomatic Personnel (outside of embassy, consulate)|
|D||International Organization (peacekeeper, aid agency, compound)|
|Food and Water Supply|
|Journalists and Media|
|N||Other (including online news agencies)|
|N||Demilitarized Zone (including Green Zone)|
|Private Citizens and Property|
|N||Refugee (including Camps/IDP/Asylum Seekers)|
|N||Laborer (General)/Occupation Identified|
|F||Procession/Gathering (funeral, wedding, birthday, religious)|
|F||Public Areas (e.g., public garden, parking lot, garage, beach, camps)|
|B||Museum/Cultural Center/Cultural House|
|B||Labor Union Related|
|N||Political Party Member/Rally|
|B||Place of Worship|
|B||Multiple Telecommunication Targets|
|B||Tourism Travel Agency|
|A||Bus (excluding tourist)|
|A||Train/Train Tracks/ Trolley|
|Violent Political Parties|
|N||Party Official/Candidate/Other Personnel|
- Marone, F. La Politica del Terrorismo Suicida; Rubbettino: Soweria Manelli, Italy, 2013; ISBN 8849839405. [Google Scholar]
- Beck, U. The Terrorist Threat: World Risk Society Revisited. Theory Cult. Soc. 2002, 19, 39–55. [Google Scholar] [CrossRef]
- Coaffee, J.; Fussey, P. Constructing resilience through security and surveillance: The politics, practices and tensions of security-driven resilience. Secur. Dialog. 2015, 46, 86–105. [Google Scholar] [CrossRef]
- Coaffee, J.; Wood, D.M.; Rogers, P. The Everyday Resilience of the City; Basingstoke Palgrave Macmillan: London, UK, 2009; Volume 10. [Google Scholar] [CrossRef]
- Morgante, G.; De Paolis, R. Implementing the EU Directive 2017/541 on Combating Terrorism in a Sustainable Balance Between Efficiency, Security and Rights: The Case Study of the Participation to a Terrorist Group. Glob. Jurist 2022, 22, 49–106. [Google Scholar] [CrossRef]
- Gasztold, A.; Szlachter, D. The Role of Anti-Terrorist Coordination Centers in the Security Systems of Germany and Poland. A Comparative Analysis. Stud. Politol. 2022, 63, 40–60. [Google Scholar]
- European Commission Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions. Action Plan to Support the Protection of Public Spaces 2017. Available online: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A52017DC0612 (accessed on 3 August 2022).
- Coaffee, J.; Bosher, L. Integrating counter-terrorist resilience into sustainability. Proc. Inst. Civ. Eng.-Urban Des. Plan. 2008, 161, 75–83. [Google Scholar] [CrossRef]
- Wolfendale, J. Terrorism, Security, and the Threat of Counterterrorism. Stud. Confl. Terror. 2006, 30, 75–92. [Google Scholar] [CrossRef]
- Coaffee, J.; O’Hare, P.; Hawkesworth, M. The Visibility of (in) security: The Aesthetics of Planning Urban Defences Against Terrorism. Secur. Dialog. 2009, 40, 489–511. [Google Scholar] [CrossRef]
- Woo, G. Understanding the Principles of Terrorism Risk Modeling from Charlie Hebdo Attack in Paris. Def. Against Terror. Rev. 2015, 7, 33–46. [Google Scholar]
- Combs, C.C.; Slann, M.W. Encyclopedia of Terrorism; Infobase Publishing: New York, NY, USA, 2009; ISBN 1438110197. [Google Scholar]
- Crenshaw, M.; Pimlott, J. Encyclopedia of World Terrorism; Routledge: London, UK, 2019; ISBN 1315480352. [Google Scholar]
- Guillaume, G. Terrorism and international law. Int. Comp. Law Q. 2004, 53, 537–548. [Google Scholar] [CrossRef]
- Blanc, L. Défense et Sécurité Nationale; Édition numérique du ministère la Défense; République Francaise: Paris, France, 2013. [Google Scholar]
- National Consortium for the Study of Terrorism and Responses to Terrorism (START) Global Terrorism Database (GTD)|. Available online: https://www.start.umd.edu/gtd/ (accessed on 3 August 2022).
- National Consortium for the Study of Terrorism and Responses to Terrorism (START) Global Terrorism Database Codebook: Inclusion Criteria and Variables; 2019. Available online: https://www.start.umd.edu/gtd/downloads/Codebook.pdf (accessed on 3 August 2022).
- Leweling, T.A.; Nissen, M.E. Defining and exploring the terrorism field: Toward an intertheoretic, agent-based approach. Technol. Forecast. Soc. Chang. 2007, 74, 165–192. [Google Scholar] [CrossRef]
- Geng, X.; Li, G.; Ye, Y.; Tu, Y.; Dai, H. Abnormal behavior detection for early warning of terrorist attack. In Australasian Joint Conference on Artificial Intelligence; Springer: Berlin/Heidelberg, Germany, 2006; pp. 1002–1009. [Google Scholar]
- Davis, P.; Perry, W.; Brown, R.; Yeung, D.; Roshan, P.; Voorhies, P. Using Behavioral Indicators to Detect Potential Violent Acts; RAND Corporation: Santa Monica, CA, USA, 2013. [Google Scholar] [CrossRef]
- Doss, K.; Shepherd, C. Active Shooter: Preparing for and Responding to a Growing Threat; Butterworth-Heinemann: Oxford, UK, 2015; ISBN 0128027835. [Google Scholar]
- Mueller, J.; Stewart, M.G. Balancing the risks, benefits, and costs of homeland security. Homel. Secur. Aff. 2011, 7, 16. [Google Scholar]
- Thöns, S.; Stewart, M.G. On decision optimality of terrorism risk mitigation measures for iconic bridges. Reliab. Eng. Syst. Saf. 2019, 188, 574–583. [Google Scholar] [CrossRef]
- Stewart, M.G. Risk of progressive collapse of buildings from terrorist attacks: Are the benefits of protection worth the cost? J. Perform. Constr. Facil. 2017, 31, 4016093. [Google Scholar] [CrossRef]
- Richardson, H.W.; Pan, Q.; Park, J.; Moore, J.E. Regional Economic Impacts of Terrorist Attacks, Natural Disasters and Metropolitan Policies; Springer: Berlin/Heidelberg, Germany, 2015; ISBN 3319143212. [Google Scholar]
- Zaidi, M.K. Risk assessment in detection and prevention of terrorist attacks in harbors and coastal areas. In Environmental Security in Harbors and Coastal Areas; Springer: Dordrecht, The Netherlands, 2007; pp. 309–316. [Google Scholar] [CrossRef]
- De Cillis, F.; De Maggio, M.C.; Pragliola, C.; Setola, R. Analysis of Criminal and Terrorist Related Episodes in Railway Infrastructure Scenarios. J. Homel. Secur. Emerg. Manag. 2013, 10, 447–476. [Google Scholar] [CrossRef]
- Frolov, K.V.; Baecher, G.B. Protection of Civilian Infrastructure from Acts of Terrorism; Springer Science & Business Media: Berlin/Heidelberg, Germany, 2006; Volume 12, ISBN 1402049226. [Google Scholar]
- Shvetsov, A.V.; Shvetsov, M.A. A Fast-Track Method for Assessing the Risk of a Terrorist Attack on Transportation Facilities. Eur. J. Secur. Res. 2019, 4, 265–271. [Google Scholar] [CrossRef]
- Lehr, P. Counter-Terrorism Technologies: A Critical Assessment; Springer: Berlin/Heidelberg, Germany, 2018; ISBN 331990924X. [Google Scholar]
- Janzon, B.; Forsén, R. Threats from Terrorist and Criminal Activity and Risk of Dangerous Accidents—Resistance and Vulnerability of the Urban Environment and Ways of Mitigation. In Resilience of Cities to Terrorist and Other Threats; Springer: Berlin/Heidelberg, Germany, 2008; pp. 3–36. [Google Scholar] [CrossRef]
- Quagliarini, E.; Fatiguso, F.; Lucesoli, M.; Bernardini, G.; Cantatore, E. Risk Reduction Strategies against Terrorist Acts in Urban Built Environments: Towards Sustainable and Human-Centred Challenges. Sustainability 2021, 13, 901. [Google Scholar] [CrossRef]
- Németh, J.; Schmidt, S. Toward a Methodology for Measuring the Security of Publicly Accessible Spaces. J. Am. Plan. Assoc. 2007, 73, 283–297. [Google Scholar] [CrossRef]
- Federal Emergency Management Agency. FEMA 430: Site and Urban Design for Security. In Guidance against Potential Terrorist Attacks; Federal Emergency Management Agency: Washington, DC, USA, 2007. [Google Scholar]
- Llewelyn-Davies (Firm); Holden McAllister Partnership. Safer Places: The Planning System and Crime Prevention; Thomas Telford Ltd.: London, UK, 2004; ISBN 0-7277-3261-7. [Google Scholar]
- Coaffee, J. Beyond Concrete Barriers Innovation in Urban Furniture and Security in Public Space; GCDN Commissioned Research, Ed.; Global Cultural Districts Network: London, UK, 2018. [Google Scholar]
- Schwarzenbach, A.; LaFree, G. Political Legitimacy and Worldwide Terrorist Attacks, 1970–2017; APSA Preprints: Cambridge, UK, 2020. [Google Scholar]
- Bader, B.; Suder, G.; Grosse, R. Terrorism as an external threat factor in global value chains. Thunderbird Int. Bus. Rev. 2019, 62, 135–148. [Google Scholar] [CrossRef]
- Chenoweth, E.; Clarke, S.E. All Terrorism Is Local: Resources, Nested Institutions, and Governance for Urban Homeland Security in the American Federal System. Politi. Res. Q. 2009, 63, 495–507. [Google Scholar] [CrossRef]
- Coaffee, J.; Wood, D.M. Security is Coming Home: Rethinking Scale and Constructing Resilience in the Global Urban Response to Terrorist Risk. Int. Relat. 2006, 20, 503–517. [Google Scholar] [CrossRef]
- Woods, J.; Ten Eyck, T.A.; Kaplowitz, S.A.; Shlapentokh, V. Terrorism risk perceptions and proximity to primary terrorist targets: How close is too close? Hum. Ecol. Rev. 2008, 15, 63–70. [Google Scholar]
- Aven, T. On when to base event trees and fault trees on probability models and frequentist probabilities in quantitative risk assessments. Int. J. Perform. Eng. 2012, 8, 311. [Google Scholar]
- Aven, T.; Renn, O.; Rosa, E.A. On the ontological status of the concept of risk. Saf. Sci. 2011, 49, 1074–1079. [Google Scholar] [CrossRef]
- Simpson, A.; Murnane, R.; Saito, K.; Phillips, E.; Reid, R.; Himmelfarb, A. Understanding Risk in an Evolving World: Emerging Best Practices in Natural Disaster Risk Assessment; Global Facility for Disaster Reduction and Recovery, The World Bank, UN International Strategy for Disaster Reduction: Washington, DC, USA, 2014. [Google Scholar]
- Daniell, J.; Simpson, A.; Murnane, R.; Tijssen, A.; Nunez, A.; Deparday, V.; Gunasekera, R.; Baca, A.; Ishizawa, O.; Schäfer, A. Review of Open Source and Open Access Software Packages Available to Quantify Risk from Natural Hazards; World Bank and Global Facility for Disaster Reduction and Recovery: Washington, DC, USA, 2014. [Google Scholar]
- Li Piani, T. Progettazione strutturale e funzione sociale dello spazio (quale) vulnerabilità e soluzione al terrorismo urbano. Secur. Terror. Soc. 2018, 8, 7–15. [Google Scholar]
- Cardona, O.D.; Van Aalst, M.K.; Birkmann, J.; Fordham, M.; Mc Gregor, G.; Rosa, P.; Pulwarty, R.S.; Schipper, E.L.F.; Sinh, B.T.; Décamps, H. Determinants of risk: Exposure and vulnerability. In Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation: Special Report of the Intergovernmental Panel on Climate Change; Cambridge University Press: Cambridge, UK, 2012; pp. 65–108. [Google Scholar]
- Kalvach, Z. Basics of Soft Targets Protection—Guidelines; Soft Targets Protection Institute: Prague, Czech Republic, 2016. [Google Scholar]
- Ministère de l’Intérieur, Ministère de la Culture et de la Communication. Secrétariat Général de la Défense et de la Sécurité Nationale Gérer la Sureté et la Sécurité des Événements et Sites Culturels; Ministère de l’Intérieur, Ministère de la Culture et de la Communication: Paris, France, 2017.
- Home Office; Centre for the Protection of National Infrastructure; National Counter-Terrorism Security Office. Protecting Crowded Places: Design and Technical Issues; Home Office: London, UK, 2012; ISBN 978-1-84987-393-2. [Google Scholar]
- Centre for the Protection of National Infrastructure Integrated Security. A Public Realm Design Guide for Hostile Vehicle Mitigation; Centre for the Protection of National Infrastructure Integrated Security: London, UK, 2014.
- Stadt Munster Public Event Safety. Guideline for Creating a Security of Concept; Stadt Munster Public Event Safety: Munster, Germany, 2017. [Google Scholar]
- NaCTSO. National Counter Terrorism Security Office Crowded Places Guidance; NaCTSO: London, UK, 2017.
- Säterhed, M.P.; Hansson, J.; Strandlund, T.; Nilsson, D.; Nilsson, M.; Locken, A.M. Event Safety Guide; Säterhed, P., Ed.; DanagårdLiTHO: Ödeshög, Sweden, 2011; ISBN 978-91-7383-206-9. [Google Scholar]
- Centre de Crise National Terrorisme et Extrémisme. Available online: https://www.info-risques.be/sites/default/files/content/download/files/bnra_terrorismeextremisme_0.pdf (accessed on 3 August 2022).
- National Counter Terrorism Security Office Stay Safe Film. Available online: https://www.gov.uk/government/publications/stay-safe-film (accessed on 3 August 2022).
- Secrétariat Général de la Défense et de la Sécurité Nationale. Faire Face Ensemble. Vigilance, Prévention et Protection Face À la Menace Terroriste 2016. Available online: http://www.sgdsn.gouv.fr/uploads/2017/01/plan-vigipirate-gp-bd.pdf (accessed on 3 August 2022).
- Gouvernement Français Vigipirate. Available online: https://www.gouvernement.fr/vigipirate (accessed on 3 August 2022).
- Centre de Crise National BE-ALERT. Available online: https://www.be-alert.be/fr/ (accessed on 3 August 2022).
|Code/Sub-Code of Terrorism Principle||Description|
|TP.1||The Impact Factor relates the concept of maximizing the terrorist attack|
|TP.1.1||Macro-terror, characterized by the reduction of the frequency due to the complexity of attack planning and execution|
|TP.1.2||Micro-terror, characterized by less management complexity and a high probability of repeatability|
|TP.2||The “Publicity Impact is Key to Targeting” highlights the perpetrator’s need to maximize media repercussion|
|TP.3||Inter-dependence and replacement of targets in compliance with the principle according to which “terrorists will attack the softer of two similarly attractive targets”. This principle can be divided into two macro-categories related to protection systems (TP.3.1 and TP.3.2)|
|TP.3.1||Hard targets, such as government buildings or military headquarters, focus the attention on buildings characterized by a system of active or passive protection technologies, regardless of the probability of occurrence. Professionals and relevant political, religious or media figures belong to this class|
|TP.3.2||soft targets, including subways, pubs, as well as vulnerable sites without any type of defence measure against these phenomena. Considering the human relevance aspect, it is referred to the community, gathered in extensive urban areas, lacking effective protection systems from the terrorist attack|
|TP.4||The characterization of terrorist weaponry, relating to the criterion of minimizing resistance, facilitates the evaluation of the level of threat and the equipment type used by the perpetrator. The same prefers traditional and easily available weapons (guns and explosives)|
|Environmental Classes (ECs)||Attack Types (Tn)|
|Code||Built Environmental Typologies||Code||Description|
|[A]||Airport, docks, metro and rail stations||[T1]||Assassination|
|[B]||Theatres, museums, bars, restaurants, hotels, shopping centers, churches||[T2]||Armed Assault|
|[C]||Hospitals, schools, universities||[T3]||Bombing/Explosion|
|[D]||Representative (symbolic) or strategic buildings||[T4]||Hijacking|
|[E]||Residential buildings and industries||[T5]||Barricade Incident|
|[F]||Open areas, squares and streets||[T6]||Kidnapping|
|5||Very likely||x > 50%||Until 1 event per day|
|4||Likely||14.25% < x ≤ 50%||Until 1 event per 2 days|
|3||Possible||3.3% < x ≤ 14.25%||Until 1 event per week|
|2||Unlikely||0.3% < x ≤ 3.3%||Until 1 event per month|
|1||Remote||x ≤ 0.3%||Until 1 event per year|
|5||Extreme (Ex)||x > 3 × 103|
|4||Major (Ma)||3 × 102 < x < 3 × 103|
|3||Medium (Me)||3 × 101 < x < 3 × 102|
|2||Moderate (Mo)||0 < x ≤ 3 × 101|
|1||Minor (Mi)||x = 0|
|Attack Types/Environmental Classes||A||B||C||D||E||F|
|Attack Type/Environmental Class||FB||FD||F|
|Attack Type/Environmental Class||FB||FD||F|
|Very high||15 < R1 < 25|
|High||8 < R2 < 14|
|Medium||4 < R3 < 7|
|Low||1 < R4 < 3|
|Likelihood Levels||Remote||All the others||F/T1||F/T4||D/T1||A/T2||C/T2||B/T1||D/T2||D/T3||F/T2||B/T5||1|
|Likelihood Levels||Remote||All the others||FB/T8||F/T4||FB/T1||F/T8||FB/T5||1|
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.
© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
Cantatore, E.; Quagliarini, E.; Fatiguso, F. European Cities Prone to Terrorist Threats: Phenomenological Analysis of Historical Events towards Risk Matrices and an Early Parameterization of Urban Built Environment Outdoor Areas. Sustainability 2022, 14, 12301. https://doi.org/10.3390/su141912301
Cantatore E, Quagliarini E, Fatiguso F. European Cities Prone to Terrorist Threats: Phenomenological Analysis of Historical Events towards Risk Matrices and an Early Parameterization of Urban Built Environment Outdoor Areas. Sustainability. 2022; 14(19):12301. https://doi.org/10.3390/su141912301Chicago/Turabian Style
Cantatore, Elena, Enrico Quagliarini, and Fabio Fatiguso. 2022. "European Cities Prone to Terrorist Threats: Phenomenological Analysis of Historical Events towards Risk Matrices and an Early Parameterization of Urban Built Environment Outdoor Areas" Sustainability 14, no. 19: 12301. https://doi.org/10.3390/su141912301