Number Of Evacuees Research Articles

Wildland fire evacuations in Canada from 1980 to 2021

Background Every year, people in Canada are evacuated due to wildland fires to avoid death, injury, and illness from fire and smoke events. Aims In this paper, we provide an overview of evacuations recorded in the Canadian Wildland Fire Evacuation Database between 1980 and 2021. Methods Our analysis covers evacuations in Canada from 1980 to 2021. We provide summary statistics including number of evacuations and evacuees, evacuation duration, seasonality, evacuation causes, community types, structure losses, and fatalities. We also investigate temporal and spatial patterns. Key results Between 1980 and 2021, there were 1393 wildland fire evacuation events with 576,747 people evacuated. During this period, there was an overall increase in frequency of evacuations, number of evacuees, and duration of events. Structure loss occurred during 194 evacuation events, with 4105 homes burned. We estimate wildland fire evacuations cost at least CAD3.7 billion (excluding structural losses), jumping to CAD4.6 billion if we include productivity losses. Indigenous peoples are disproportionately impacted in wildfire evacuations compared to the general Canadian population. Conclusions Wildland fire evacuations continue to occur across Canada and are increasing. Implications The findings from this study give us a better understanding of the characteristics of wildland fire evacuations, which can help guide emergency management.

A modified social force model for crowd evacuation considering collision predicting behaviors

The social force model is one of the most common models used in the study of pedestrian dynamics. In the social force model, there are oscillation in the movement of pedestrians. To address the oscillation phenomenon, this paper modifies the way of setting psychological forces and judgment conditions based on previous research. By comparing the simulation results with the real experimental results, the evacuation time results are basically the same, which validates the effectiveness of the modified social force model. The simulation results show that the modified social force model eliminates the phenomenon of evacuee velocity oscillations near fixed obstacles in the original model and fixes the phenomenon of abnormal behavior of evacuees during collisions. In addition, we simulate different numbers of evacuees (i.e.,25,50,100,200) and the results show that the modified social force model successfully replicates the phenomenon of arch congestion during evacuation.

A study of evacuation model based on personnel vision change

This paper proposes a new model for characterizing the emergency evacuation process of people during a disaster. This model considers the change of visual field based on a cellular automata model combined with a behavioral heuristic model. Using the behavioral heuristic model, the dynamic field parameters related to the change of visual field are first established. Then, new judgment rules are developed for personnel encountering obstacles by combining the characteristics of the new field of view. Finally, an analytical comparison is made between the proposed model and the traditional evacuation model in terms of the changes in the fields of view and the number of evacuees. The results show that the level of path service determines the efficiency of evacuation. It is also seen that herd mentality acts as a hindrance in cases where the personnel are dependent while otherwise acting as a facilitator. It is also shown that the evacuation time increases by the number of evacuees up to a certain threshold. Beyond that threshold the evacuation time fluctuates within a certain range by increasing the number of evacuees is not affected by changes in the field of view. The new model is also faster than the social force model, easier to calculate on a large scale, and more realistic than the traditional cellular model.

A Study on the Evacuation of an Extra-Long Highway Tunnel Fire—A Case Study of Chengkai Tunnel

The smoke from tunnel fires spreads over long distances and is difficult to vent. Smoke accumulation leads to high temperatures, low visibility, and high concentrations of toxic gases, which greatly hinders the evacuation of people inside the tunnel. In this paper, a representative extra-long highway tunnel—Chengkai Tunnel—is selected as the engineering background, and a tunnel model is built using FDS and Pathfinder software to simulate the fire scenario and evacuation scenario under different longitudinal wind speeds. The concept of safe evacuation reliability is proposed to describe the relationship between the ASET (available safe egress time) and the RSET (required safe egress time). The simulation results show that with the increase in longitudinal wind speed, the ASET upstream of fire source increases first and then remains unchanged, while ASET downstream of fire source increases first and then decreases. The ASET upstream of the fire source is affected by visibility, while the ASET downstream of the fire source is affected by visibility when the wind speed is low, and is affected by temperature as the wind speed increases. The bottleneck effect is an important reason for the long evacuation time of people. The blockage time is a power function of the evacuation movement time, and increasing the width of the cross passage can improve the evacuation efficiency of the tunnel. The increase in the number of evacuees will reduce the reliability of the safe evacuation of personnel. Among all simulated scenarios, a longitudinal wind speed of 2.5 m/s has the highest safe evacuation reliability, with 0.79, 0.92, and 0.99 for scenarios R1, R2, and R3, respectively. Excessive wind speed reduces the safe evacuation reliability downstream of the fire source.

Emergency Escape Route Design and Application

This paper uses k-means clustering algorithm, single objective optimization model and multisource multi-sink problem shortest path algorithm to obtain the optimal path algorithm for emergency evacuation and the shortest time model.Firstly, a code of conduct for the division of terrorist attacks has been established. The number of casualties in various incidents and the scope of destructive power to public areas are counted. A three-dimensional cluster core is selected. All terrorist at- tacks are classified into three levels: level 1-3 by the k-means clustering algorithm, and the degree of harm is gradually increasing.Secondly, the optimal path from each venue to the stairway is calculated. The re- lationship between the speed of flow and the number of evacuees is given in the case of three situations. The multi-source multi-sink problem is transformed into a single- source shortest path problem by adding a virtual node to all venues on the second floor of the Louvre, and the Dijkstra algorithm is called once to obtain the optimal path from the venue to all stairs.The Final step is to establish an emergency evacuation optimization model with the minimum evacuation time as the objective function. The overall evacuation time is divided into the personnel response time, the horizontal road walking time, the time down the stairs, and the waiting time when congestion occurs. the open number of emergency exits can be judging by different levels of terrorist events, and the optimal evacuation path and the shortest time for different emergency events are given. At the same time, we also analyzed the changing trend of velocity in different cases, which can be adjusted according to the actual conditions.

A simulation-based optimization method for emergency evacuation induced by gas pipeline leakage risk

Long-distance gas pipelines with large diameter and high pressure, on which a leakage induces gas diffusion or fire explosion, may result in major influence to nearby buildings and residents. Safety and rapid evacuation of potentially affected people is a top priority. To analyze the affected areas by disasters and improve evacuation efficiency of the affected areas, this study presents a simulation-based optimization method for emergency evacuation induced by gas leakage risk. First, the influence radii of different leakage accidents were calculated based on damage criteria and the evacuation radii around the accidents were determined considering the panic psychology. The number of evacuees and their spatial distribution were calculated. Secondly, an evacuation simulation model for affected communities based on the multi-agent system was established to analyze the evacuation process of residents. Finally, the optimal design method and strategies for community evacuation were proposed. Responsibility areas of organized evacuation service for community exits were determined. The results showed that the evacuation times of the two communities A and C were reduced by 10% and 24%, which indicates organized evacuation is more efficient than unorganized evacuation. The selection of community exits is more balanced. Its rationality of the proposed method was verified by the comparison of evacuation simulation.

Simulation-based heterogeneous pedestrian evacuation in subway stations

Pedestrian heterogeneity is one of the important factors affecting evacuation efficiency in subway stations. This paper mainly studies the impact of pedestrian heterogeneity on evacuation based on simulations. With the help of Massmotion, the Qingdao Jinggangshan Road subway station is modeled. The social force model is used as the pedestrian dynamics model and the minimum cost model is used as the decision-making mechanism of pedestrian path selection. The models are verified by comparing the field data with the corresponding simulation data. Fully considering the impact of different pedestrian attributes on evacuation efficiency, pedestrians are divided into three categories with different speed levels and three categories with different body size levels. Simulation experiments are carried out by adjusting the proportional relationship of the number of pedestrians with different attributes. The simulation results indicate that the larger the proportion of fast pedestrians under the same number of evacuees, the higher the evacuation efficiency to a certain extent. The evacuation efficiency could be reduced accordingly with the increase in the proportion of pedestrians with large body sizes. When the pedestrian density is large, the impact of pedestrian heterogeneity on evacuation cannot be clearly reflected. Moreover, the quantitative fitting relationship between evacuation time and pedestrian quantity could be obtained. This paper provides a theoretical basis for the determination of evacuation strategy for the heterogeneous crowd.

A New Quantitative Triage System for Hospitalized Neonates to Assist with Decisions of Hospital Evacuation Priorities.

Hospitalized neonates are vulnerable to natural and man-made disasters because of their persistent requirement for medical resources and may need to be evacuated to safe locations when electricity and medical gas supply become unreliable. In Japan, a triage system for hospitalized neonates, or the Simple Triage and Rapid Treatment for Neonates, Revised (START-Neo-R), has been used to determine whether neonates are in suitable conditions for transportation. However, this scale is not useful to determine the evacuation order of neonates because a considerable number of evacuees are classified into the same categories. To solve this problem, a novel triage system, Neonatal Extrication Triage (NEXT) was developed. This study tested the validity and reproducibility of both triages and compared them with a standardized prognostic scoring system for hospitalized neonates, the Neonatal Therapeutic Intervention Scoring System (NTISS). In this retrospective observational study, physicians and nurses independently assessed each neonate hospitalized at a tertiary neonatal intensive care unit (NICU) twice weekly using NEXT and START-Neo-R. The NEXT system comprises six questionnaires regarding medical resources required during transition and transportation, providing composite scores on a 12-point scale. The START-Neo-R classified neonates into five levels based on the severity of disease and dependence on medical care. Inter-rater reliability of both systems was assessed using Cohen's kappa coefficient, whereas the criterion validity with NTISS was assessed using Spearman's correlation coefficient. Overall, 162 neonates were assessed for 49 days, resulting in triage data for 1,079 accumulated patients. Both NEXT scores and START-Neo-R ranks were well-dispersed across different levels without excessive accumulation in specific categories. Inter-rater reliability of NEXT (kappa coefficient, 0.973; 95% confidence interval, 0.969-0.976) and START-Neo-R (kappa coefficient, 0.952; 95% confidence interval, 0.946-0.957) between physicians and nurses was sufficiently high. The correlation coefficient of NEXT and START-Neo-R scores with NTISS scores were 0.889 (P <.001) and 0.850 (P <.001), respectively. Both START-Neo-R and NEXT had good reproducibility and correlation with the severity of neonates indicated by NTISS. With its well-dispersed scores across different levels, the NEXT system might be a powerful tool to determine the priority of evacuation objectively.

Evacuation Strategy Considering Path Capacity and Risk Level for Cruise Ship

Cruise ships are large and complex, and it is difficult to manually make a plan to evacuate people to safe areas in a short time. Evacuation time and personnel safety are both important for emergency evacuation. This paper proposes an evacuation strategy that considers the path capacity and risk level to guide evacuees in fire; it not only ensures the safety of people on dangerous paths but also reduces road congestion to shorten evacuation time. High crowd density means slow moving speed, an exponential function including straight path and stairs speed characteristics is proposed to illustrate the relationship between crowd density and moving speed. Path capacity constraints are used to avoid the congestion caused by the evacuees in a panic. In order to evacuate the evacuees in the risk areas as soon as possible, this paper divides the path into three risk levels according to carbon monoxide concentration, visibility, and temperature along the paths. The people on the higher-risk paths are given higher priority to enter evacuation paths than those on lower risk. The priority strategy evacuates the people on risk paths to safe areas in less time. This paper models the evacuation network topology of a cruise ship and simulates the evacuation process of some situations that have different numbers of evacuees and path capacity constraints. The evacuation strategies and simulation results are guidelines for the crews to guide the people to evacuate to safe areas when there is a fire accident on the cruise ship.

출입문 임시폐쇄에 따른 피난시간 변화에 관한 연구

This study analyzed the evacuation time of occupants before and after the temporary closing of the entrance to building among educational research facilities in order to understand time of occupants when the entrance of an existing building is temporarily closed for control purposes. The results are as follows. Firstly, the occupants evacuated through the adjacent door after vertical evacuation using the stairs and the three doors used were adjacent to the stairs before the temporary closing of the door. In particular, it was confirmed that the entrances located at both ends of the building were not used by occupants for evacuation because they were far apart from the stairs. Secondly, after the temporary closing of the door, the occupants start evacuation without recognizing the locked state of the door. As they evacuate again, the time required to complete the evacuation increases and the time required due to restrictions on the available doors is accumulated. Thirdly, it was confirmed that the difference in evacuation completion time between the occupants before and after the temporary closure of the entrance door was about 2.2 times. In particular, the number of evacuees per hour is up to ten simultaneously evacuating at the same time before the temporary closure, but up to three simultaneously evacuating at the same time after the temporary closure. Thus, the number of entrances has a significant impact on evacuation. Lastly, for the convenience of blocking the inflow of COVID-19, creating an electronic list for users and checking temperature, it is necessary to install devices such as “automatic opening and closing of entrances” to ensure the safety of occupants in emergencies such as fires.

Simulation of spontaneous leader–follower behaviour in crowd evacuation

The leader–follower (L-F) relationship is believed to be the fundamental mechanism explaining the collective behaviour of a crowd. However, previous models are inherently limited in that they simulate a pre-defined L-F behaviour using simple heuristics. In this paper, we propose a new approach to measure the emergence of spontaneous L-F behaviour in an evacuating crowd using an information-theoretic and model-free method, i.e., transfer entropy (TE). The dynamic characteristics of evacuees (e.g., their trajectories, movement patterns and density plot) in a room (or corridor) are clearly visualised by the proposed TE-incorporating force-based model. The results show that the overall evacuation time decreases as the TE threshold increases. The trajectories occur in congested clusters when the TE threshold is low, but become more dispersed and uniformly distributed in scenarios with higher TE thresholds. In terms of group size, a spontaneous L-F group normally consists of one leader and one follower. L-F groups of larger-size (i.e., more than three followers of a leader) tend to disappear with increasing TE threshold. Lastly, we examine the location of spontaneous leadership emergence. Irrespective of the geometric layout or the number of evacuees in a room or corridor, the threshold at which distinct L-F patterns emerge is always approximately I¯TE = 0.5. By innovatively integrating the TE approach into a force-based model, this study suggests a novel method for leadership identification during crowd evacuation given no prior knowledge.

Simulation of tsunami evacuation behavior considering inland direction

Many lives have been lost in various earthquakes and tsunami disasters around the world. In Japan, future earthquakes originating in the Nankai Trough and Hyuga-nada Sea are expected to cause strong tremors and large tsunamis over a wide area along the Pacific coast. Previous tsunami evacuation studies have considered only the distance to the nearest evacuation facility and the need to evacuate to higher ground outside the inundation zone in their simulations. However, tsunami evacuees rarely evacuate toward the sea, even to reach a nearby evacuation facility, because of the counterintuitive nature such movement. In this study, we accordingly conducted agent-based tsunami evacuation simulations in Takanabe town, Miyazaki Prefecture, to compare the evacuation ratio when agents evacuated to their nearest facility regardless of direction with that when they evacuated to their nearest inland facility. The results showed that the evacuation to the inland facilities took more time to complete early in the evacuation process than the evacuation to the nearest facilities. Furthermore, the evacuation to the inland facilities resulted in large differences in the number of evacuees at some evacuation facilities compared to the evacuation to the nearest facilities. It is therefore necessary to consider the direction of the coastline when planning tsunami evacuations.

Study on influence of prior recognition of flooding state on evacuation behavior

In recent years, disasters have caused extensive water damage in various parts of Japan. Flooded evacuation routes and ineffective hazard maps commonly constrain evacuees’ behavior, which results in casualties. In this study, storm surge flooding analysis was carried out using OpenFOAM, which is a computational fluid dynamics software that monitors flooding state as a function of time, and evacuation simulations using a multi-agent system that considers evacuation behavior knowing the flooding state established by the flooding analysis. In some of the scenarios, many residents were caught in the flooding and could not be evacuated. Additional evacuation simulations revealed that evacuation behavior is more effective if residents have advance knowledge of the area expected to flood. Identifying these flood hazard areas and recognizing these areas in advance as impassable enables evacuees to avoid flood hazard areas; consequently, there is a decrease in the number of evacuees who get caught in the flooding. Anticipating the area expected to be flooded suggests the best evacuation locations and routes. Using these simulation results with useful hazard maps and disaster education, residents will correctly recognize the risk of a storm surge disaster and prepare for it, which will assist recovery. Finally, our analytical and simulation approach to disaster management is amenable to long-term planning for disaster-resistant cities.

Potential of mosques to serve as evacuation shelters for foreign Muslims during disasters: a case study in Gunma, Japan

Foreigners tend to be vulnerable to disasters due to religious and cultural differences. In Japan, Muslim foreign residents, who are minorities, likely face difficulties in terms of food and religious practices in evacuation shelters. In this study, we propose the use of mosques as voluntary shelters for Muslim foreigners in Japan and evaluate their potential to function as shelters. Mosques are expected to have a large space, including a prayer space, and to store food familiar to daily users. We conducted field surveys targeting two mosques in Isesaki, Gunma, Japan, to investigate their equipment and building environment in relation to how they could function as shelters; the number of evacuees they could accommodate; the amount of food they could supply to evacuees; and the willingness of the administrators to use the mosques as shelters. Both mosques were found to be equipped with toilets and shower rooms and had enough space for approximately 60–80 evacuees. They also had sufficient kitchen space and tableware to prepare meals for about 100 people. Although they did not always stock a large amount of food, they could quickly receive food from nearby stores. Moreover, the administrators were willing to use the mosques as shelters. Therefore, it was suggested that the mosques could serve as shelters accommodating and feeding many evacuees. Finally, measures to improve the function of mosques as shelters are discussed. This study lays the groundwork for the future use of mosques as shelters.

Influences of wing gate turnstiles' characteristics on pedestrian evacuation based on agent-based egress model.

Wing gate turnstiles are widely used in airports, subway stations, railway stations, movie theaters, parks, etc., and influence the pedestrian evacuation greatly while accidents happen. Thus, doing some researches on how to improve the evacuation speed for wing gate turnstiles are meaningful and necessary. In response to this issue, the influences of the wing gate turnstiles on pedestrian evacuation are investigated by pathfinder in this paper. Pathfinder is an agent-based egress simulator that uses steering behaviors to model occupant motion. First of all, by Pathfinder, two evacuation models with flat-shaped and wedge-shaped hosts wing gate turnstiles, respectively, are established, and the simulations of pedestrian evacuation are carried out by computer. The results show the evacuation speed obtained by the wedge-shaped host is faster than that obtained by the flat-shaped host. Moreover, the longest evacuation time is obtained when the channels' width is 90 cm, and the shortest is obtained when the channels' width is 51.4 cm. For a small number of evacuees, the evacuation time is mainly influenced by the original distributions of the evacuees, however, as the number of the evacuees increases, the evacuation time is mainly influenced by the number of the evacuees. Furthermore, the wing gate turnstiles with widened hosts can get less evacuation time no matter whether the hosts are flat-shaped or wedge-shaped, however, the evacuation-time-saved rate obtained by wedge-shaped host is much higher than that obtained by flat-shaped host. Then, the influences of the wedge angle on the pedestrian evacuation are discussed, and the optimal wedge angle is obtained. The obtained results can not only provide helps for managers to evacuate crowds under emergency, but also offer some assistances for designers to design those gate turnstiles or building exits.

An investigation of fire evacuation performance in irregular underground commercial building affected by multiple parameters

Irregular underground commercial buildings (IUCB) are difficult to evacuate because of large space depth, complex form changes, and dense crowd. Fire evacuation performance of IUCB is of great practical importance with the development of underground buildings. To analyze the influence of different evacuation parameters on the properties of IUCB fire evacuation, this research gives person evacuation time under different strategies, action time of agent, and evacuation time based on IUCB fire evacuation numerical analysis model. A virtual reality system (VRS) including testing equipment and record platform is designed to perform model validation. Influence of three parameters are also analyzed on the performance of IUCB fire evacuation, including evacuation numbers, minimal group effect and pre-action time. Social force model and Generalized random graph model are applied to behaviors of evacuee. The results show that crowd congestion becomes a key factor determining evacuation time after the number of evacuees’ increases by 50.0%. The unbalanced use of exits reduces the overall evacuation rate. The average evacuation time, the overall evacuation time, and the total evacuation time of 95.0% population increase by 13.3%, 36.0%, and 15.9% respectively. When 50.0% of the evacuees are set as the minimal group effect, the overall evacuation time increased by the minimal group effect aggravates the congestion in some routes, but the minimal group effect could reduce the long tail time. Reducing the pre-action time can improve the overall evacuation rate in the early stage of evacuation. The basic linear relationship between pre-action time and evacuation time is presented. This research can provide the guidance for exit fire evacuation for IUCB to be built, which can also reduce the evacuation time in fire evacuation.

Investigating Evacuation Trends and Restoration Processes from Serious Earthquake Damage in Japan

Japan has experienced many large-scale natural disasters, such as earthquakes, typhoons accompanied by heavy rain, and landslides. Based on data for the damage caused by four recent major earthquakes in Japan, we investigate the trends in the number of evacuees and evacuation centres after these disasters as well as the restoration processes for public utilities such as electricity, gas, water, and communication lines. We compare the restoration speeds and trends of the damaged infrastructure systems. We also propose various mathematical models to approximate the recovery trends using both evacuee-related data and damage recovery process data. These results can be used to design natural disaster mitigation policies not only in Japan, but also in other countries. The results of various statistical data analyses and mathematical modelling techniques are applied to provide policy suggestions.

Evacuation strategies for vertical ship lift during initial fire: Integrated application of stairs and elevators

Vertical ship lifts (VSLs) are widely used in navigation facilities worldwide because of their efficiency and low cost. Although several researchers have investigated fire evacuation strategies for reducing potential safety hazards in VSLs, an effective and integrated application of stairs and elevators when a fire occurs in a VSL is necessary. Several evacuation routes were analyzed according to VSL structure and evacuation times in this study. Objective function corresponding to the minimum vertical evacuation time and related simulation model was subsequently developed to obtain a cooperative evacuation plan considering different numbers of evacuees. The Three Gorges ship lift was used as an example, and simulation results indicate that number of evacuees and exit selection are the main influencing factors of the total evacuation time in the stair- and elevator-coordinated evacuation mode. Furthermore, the distance between people trapped in ship reception chamber and evacuation exits affects evacuees’ choice of exits. The proposed model can provide a theoretical reference for evacuation research during initial fire events in VSLs.

Incorporating Tacit Knowledge of Experts in the Assessment of Shelters Under Disaster.

During disasters, prompt assessment of evacuation centres and appropriate measures taken based on the assessment are important for protecting local residents' lives and health. To clarify experts' tacit knowledge for improving the management of shelters under disaster, we conducted a questionnaire survey of specialists in disaster management to examine the assessment items to which they accorded top priority. Our results suggest that specialists give highest priority to the number of evacuees, followed by infrastructure and need for medical intervention. Identifying their common views on priorities can be the first step towards taking standard appropriate measures in evacuation centres.

An agent-based simulation framework for analysing fall risk among older adults in the evacuation procedures

Poor performance during an emergency evacuation from a residential building can lead to serious injuries (even death) and loss of property. As a result, it is paramount that evacuation plans are designed to account for both the physical (or geometrical) limitations of the space, such as the stairway designs, and, more importantly, the physical condition of those living in the building. Generally, when egress planning is considered or modelled during the design phase of a building, it is assumed that its residents are sampled from an average population with an average mobility condition. As a result, older adults tend to be ignored or regarded as part of the average population in the evacuation simulations. Due to their vulnerability, it is common to see older adults suffer from falls, which may result in serious trauma, such as fractures, from which older adults often do not fully recover. Moreover, many of the adverse effects that can occur during an evacuation, including the risk of falling, is compounded when a larger number of individuals try to exit a building within a short time interval given the geometric constraints of the built environment and the (limited) physical capacity of the residents. To analyse the risk of falling among older adults in evacuation procedures, this paper proposes an agent-based simulation framework, which consists of three primary components: agent-based modelling, fall risk index establishment, and fall risk assessment for older adults in an evacuation scenario. A case study of an apartment-style seniors’ residence in Edmonton, Canada is provided to demonstrate the applicability of the framework in evaluating fall risk among older adults. Furthermore, a sensitivity analysis is conducted to better understand how the number of evacuees and different designs of the built environment influence both the fall risk of individuals and the fall risk attributable to the built environment.