Evacuation Strategies Research Articles

A Staged Evacuation Methodology for Emergency Preparedness Plan

ABSTRACT Early public protection measures play an important role in reducing the health effects of radiation exposure. In particular, a staged evacuation is recognized as the most important strategy. However, studies on segmenting an evacuation region with non-uniform population density are lacking; therefore, the purpose of this study is to gain insight regarding this topic. First, the evacuation region was determined by comparing the level 3 probabilistic safety assessment (PSA) results with the generic-dose limit. Second, we performed mathematical approaches to calculate the evacuation and delay time. We then scored staged evacuation strategies and selected the best strategy. Through this study, we found some features as follows: (1) the evacuation and delay time have a trade-off relationship, (2) there is no significant difference in total evacuation time except for the preparation time, and (3) there is a big difference in total delay time despite the same segmentations. Namely, even if the evacuation time may be the same, the delay time may differ. The delay time can be defined as the period that people spend on the road, and so the longer the delay time, there is an increased likelihood of receiving unnecessary exposure.

Simulation Research on Fire Evacuation of Large Public Buildings Based on Building Information Modeling

Reasonable evacuation strategies are important in reducing casualties in the event of a fire. In this work, we conduct a simulation of a fire evacuation of a large public building based on the building information modeling technology to find the best evacuation strategy. We identify the tolerance limit of evacuees in case of a fire as the basis of the simulation using the fire dynamics simulator software. The following four evacuation strategies are proposed and simulated: stratified evacuation only by stairs, stratified evacuation mainly by stairs and supplemented by fire elevators, holistic evacuation only by stairs, and holistic evacuation mainly by stairs and supplemented by fire elevators. The case study of a college canteen shows that if 10% of evacuees (mainly elderly people who walk slowly and children who take up less space) are instructed to evacuate via fire elevators and the other 90% of evacuees (young men and women who move fast) use the stairs, the evacuation time can be reduced to a minimum. Some improvements in the design drawing result in the enhanced efficiency of the proposed strategy. The findings of this work are of great significance for the optimization of the structural design of large public buildings and provide some references for emergency evacuation.

On the effectiveness of multi-feature evacuation systems: an agent-based exploratory simulation study.

Evacuation modeling and simulation are usually used to explore different possibilities for evacuation, however, it is a real challenge to integrate different categories of characteristics in unified modeling space. In this paper, we propose an agent-based model of an evacuating crowd so that a comparative analysis of a different sets of parameters categorized as individual, social and technological aspects, is made possible. In particular, we focus on the question of rationality vs. emotionalism of individuals in a localized social context. In addition to that, we propose and model the concept of extended social influence, thereby embedding technological influence within the social influence, and analyze its impact on the efficiency of evacuation. NetLogo is used for simulating different variations in environments, evacuation strategies, and agents demographics. Simulation results revealed that there is no substantial advantage of informational overload on people, as this might work only in those situations, where there are fewer chances of herding. In more serious situations, people should be left alone to decide. They, however, could be trained in drills, to avoid panicking in such situations and concentrate on making their decisions solely based on the dynamics of their surroundings. It was also learned that distant connectivity has no apparent advantage and can be ruled out while designing an evacuation strategy based on these recommendations.

WildfireNet: Predicting Wildfire Profiles (Student Abstract)

Forecasting an accurate wildfire profile is an essential tool for firefighters when planning an evacuation strategy. Therefore, we propose a WildfireNet that can predict the shape of the wildfire of the next day, when given historical wildfire profiles, elevation, and weather data. The motivation behind WildfireNet is to locate fires in a precise manner and be able to accurately predict upcoming fires. The model’s architecture was built in the inspiration of U-Net, which is a Convolutional Neural Network (CNN) commonly used in a biomedical image segmentation. Intersection over Union (IoU) and recall were calculated to measure the performance of the model. The model achieved an IoU score of 0.997 in the test set. Since the objective of the model is to predict upcoming fires, pixels that were labeled as fire but not on the previous days were extracted to calculate recall. In the test set, Wild-fireNet scored a recall of around 0.75 for fires that grew slowly. Overall, WildfireNet is a novel wildfire spread model and has the potential to be a tool to aid firefighters in their decision making.

Retracing evacuation strategy: A virtual reality game-based investigation into the influence of building’s spatial configuration in an emergency

ABSTRACT During evacuation, individual navigation behavior is often dictated by the legibility of evacuation signs and the environmental setting itself. People tend to follow previously-used and known routes (to retrace) rather than follow evacuation signage. This has proven undesirable, even fatal, in emergencies and such behavior calls for a better understanding of the influencing factors. This contribution consists of a virtual reality experiment in which 72 participants evacuated from a hotel building in which the spatial configurations were altered. The tendency to retrace diminished when the evacuation route led through a wider, straight corridor, suggesting that the building’s spatial configuration has an important influence on retracing and should be more carefully considered in the design of buildings in and agent-based simulations.

Evacuation Shelter Decision Method Considering Non-Cooperative Evacuee Behavior to Support the Disaster Weak

In disaster situations, special support for the disaster weak are crucial to keep them safe. Common evacuation strategies guide individuals to the shelters closest to their present locations. If evacuees are unevenly distributed across areas, some shelters will not be able to accommodate all arriving evacuees due to the limited capacity of shelters. To tackle this, the existing method decides the destinations for each evacuee considering congestion in disaster areas. However, this method does not consider the disaster weak and can be burdensome for them. Giving that the priority to the disaster weak for shelter decision would be effective to lessen burdens for them, but not all evacuees follow the guidance. When a shelter accepts arriving evacuees unconditionally, some evacuees are rejected, causing a delay in evacuation. If the disaster weak are rejected, the delay will be increased. In this paper, we propose two evacuation shelter decision methods considering the capacity of shelters, the disaster weak, and evacuees’ selfish behavior to realize quick evacuation for the disaster weak: (1) Fixed-rate Reduction Method (FRM), which reduces the assignment number of evacuees less than the capacity at the same percentage to all shelters. (2) Simulation-based Reduction Method (SRM), which reduces the assignment number to shelters that will be crowded based on simulation of an evacuation scenario. Then, these methods decide the destinations for evacuees, with the priority given to the disaster weak. To evaluate the efficiency of the proposed methods, we conducted multi-agent simulation assuming the scenario of evacuation of 30,000 visitors for the Gion Festival including the disaster weak. Through the simulation, we compared our methods with conventional methods including the nearest shelter selection method and the exiting method. As a result, our methods can reduce evacuation time of the disaster weak compared to conventional methods with sufficient cooperation by evacuees.

Strategy evolution of panic pedestrians in emergent evacuation with assailants based on susceptible-infected-susceptible model

Panic pedestrian evacuation in emergent situations with assailants is of great practical significance. Although game theory have been applied to analyze pedestrians’ decision making in pedestrian evacuation, there are fewer works addressing strategy evolution of panic pedestrians in emergent evacuation with assailants. To fill this gap, this paper built a new model for emergent evacuation with assailants (called EEA-SIS) based on Susceptible-Infected-Susceptible model (SIS). In our model, pedestrians’ decision-making is guided by game theory models . Pedestrian-relationship network is built to indicate pedestrians’ interaction. The process of changing evacuation strategy between cooperation and defection is indicated through the SIS model on this pedestrian-relationship network. Experiments are conducted on four different social dilemmas related to four evacuation scenarios. The simulation results show that with the evolution of pedestrian-relationship network, the evolution trend of different types of pedestrians’ strategies has changed significantly. A sensitivity test is carried out to investigates the influence of panic value on the strategy evolution of pedestrians and show the possible behavior changes of them. Several useful results are obtained for safety management. Finally, comparison experiments show that both evacuation time and casualty in our model are less than those in the classical agent-based model for all evacuation scenarios.

The existence of cautious pedestrians might facilitate evacuation dynamics

How to accurately simulate the real collective behavior of pedestrian evacuation remains an important issue in research of complex systems. The existing crowd simulation models in general assumed that pedestrians move directly towards the exit. In real life, however, there exist “cautious” pedestrians who fear trampling and crowding during evacuation, so we use an improved social force model to investigate how their presence influences evacuation dynamics. Simulation results reveal that the total evacuation time does not increase monotonically with the increment of the number of cautious pedestrians. Specifically, the presence of a moderate number of cautious pedestrians with rational psychological tolerance might substantially facilitate evacuation efficiency, compared with a conventional evacuation scenario. In addition, lower psychological tolerance promotes emergency evacuation, while increasing the tolerance threshold is conducive to slow evacuation. We hope that our research will provide some insights into the reasonable optimal strategies for emergency evacuation.

Special Issue on Actions Toward Futuristic Urban Flood Risk Research and Management

As rainfalls exceeding the designed level have increased, so has damage associated with pluvial flooding. Typhoon Hagibis, which swept Japan in 2019, left 140 municipalities in 15 prefectures scarred from flooding. The sewage networks damaged by the typhoon affected civic life by paralyzing urban functions, raising concerns in urban flood risk and management. Increases in heavy rainfall events associated with global climate change are expected to increase damage from pluvial flooding, thereby necessitating reviews of current urban flood risk management for the purpose of making further improvements against future threats. As we enter an era of frequent urban flooding, it is vitally important that we prepare for urban flood risk management by sharing scientific and technological knowledge among academics, private companies, and administrators. In this context, the current issue is a compilation of contemporary research studies in academia, technological advances in private companies, and practical applications in public administrations in Japan. The works include: the application of urban flood modeling in safe evacuation strategies, the assessment of economic loss, and the impact of climate change; state of the art technologies for urban flood management with the Internet of Things (IoT) and Internet Communication Technology (ICT), Unmanned Aerial Vehicles (UAV), and the next generation of weather radars; and best practices for flood countermeasures, based on knowledge and experience from historical flooding and applied in prefectural governments and local municipalities. We are grateful to all the authors and reviewers who contributed to this special issue, and we hope that it may internationally enhance knowledge-exchange in preparation for growing urban flood risks.

Fire emergency evacuation model of light rail station based on BIM technology

Urban light rail undertakes the mission of escorting passengers to arrive safely. Once a fire accident occurs, it will inevitably have a great negative impact. Therefore, how to effectively carry out emergency evacuation tasks in fire accidents has become one of the problems facing the development of urban rail transit. Based on this, this article first introduces the relevant characteristics of BIM technology and the corresponding advantages, and further its use in urban light rail stations. The application advantages of emergency evacuation strategies are briefly analyzed; then the requirements for the construction of BIM emergency evacuation models are studied; finally, through field investigations, a specific urban rail transit light rail station is taken as an example to construct a BIM building information model for this light rail station. Applying BIM technology to fire protection work in light rail stations, it is expected to improve the efficiency of emergency evacuation of passengers in light rail stations.

Study on the exit-selecting behavior in underground indoor space with fire using a virtual experiment

The fires in underground indoor space often result in limited field of vision, thus revealing the characteristic of exit-selecting behavior under the influence of fire and limited view is the basis for optimizing exit layout and emergency evacuation strategies for the underground spaces. In this study, an interactive virtual environment is presented and using which an evacuation experiment is carried out to test human exit-selecting behavior in fire scenario. The results show that when the view is limited, more exits and arranging the exits evenly are helpful to shorten the time of seeking the available exits. If there is congestion in front, as long as the information on the exits is sufficient, some people (more than 20%) will re-select the other exits. Furthermore, people prefer to spend more movement time reducing queuing time. When the dynamic temperature field is used to show the participants a spreading fire, the virtual fire plays a certain threat, so most of subjects (96.7%) prefer the exit away from the fire source. Moreover, if there are other pedestrians, the evacuation decision-making process of personnel is the game process among selecting the fastest path, keeping away from the exits near the fire source and avoiding high temperature field. The results also show that individual age has an obvious correlation with the participants’ ability of escaping in the virtual evacuation environment. Specifically, the ability tends to become weaker as the age increased. This study will be useful to understand the human exit-selecting behavior and movement characteristics in the influence of fire and limited view by using a cheap and safe method.

Evacuation Model of Emotional Contagion Crowd Based on Cellular Automata

Crowd evacuation under emergency is an important task of world public security research and practice. In order to describe the microemotional contagion of evacuation individuals, a cellular automata-based evacuation model of emotional contagion crowd based on the classical SIS model of infectious diseases is proposed in this paper. Firstly, the state of evacuation individual is defined as “emotional susceptible” and “emotional infective.” Then, a dynamic model considering emotional contagion is established with cellular automata. Based on the models of static floor field and dynamic floor field, the emotion updating rules and state updating rules are constructed. The influence of perception domain radius on pedestrian evacuation process is analyzed through experiments. The conclusion can provide evacuation guidance for evacuation individuals. The comparative experiment results show that the improved model can reflect the movement characteristics of evacuation individuals effectively. The evacuation efficiency of the whole system is also effectively improved due to the consideration of emotional contagion and evacuation strategy.

Assessment of Social Vulnerability in the Evacuation Process from Mount Merapi: Focusing on People’s Behavior and Mutual Assistance

In Merapi volcano mitigation, the cooperation within/between the local communities is a key strategy for effective evacuation. In the “sister village” scenario, the meeting area and shelter have been coordinated, but people’s behavior has not been fully considered yet in the vulnerability assessment and government’s contingency plan. The purpose of this study is to assess the people’s behavior, mutual assistance, and social vulnerability index of pedestrian evacuation in four affected regencies. First, we measured the walking speed directly, conducted interviews with stakeholders, and focus group discussions with local communities. We used the multicriteria method and focused on two factors, social and age structure (young, vulnerable, and mutual assistance between them), and risk perception (work, rain, night, alert, and destination). The index reflects the distribution of actual walking speed, mutual assistance, and the government’s plan. The result showed that mutual assistance groups have a higher walking speed than vulnerable people but lower than young people. Mutual assistance coordination is crucial to support vulnerable to effective travel time. The social and age structure of the social vulnerability index has a stronger risk influence than the perception factor in the evacuation process. However, these two factors have a minor impact on social vulnerability to the total population.

Improvement of Evacuation Modeling by Considering Road Blockade in the Case of an Earthquake: A Case Study of Daitoku School District, Kanazawa City, Japan

In disaster management, evacuation modeling is considered a useful visual tool to disaster managers for reviewing current evacuation strategies, estimating the ability of shelters to accommodate all evacuees, and developing evacuation route planning. Though there are several existing studies on evacuation modeling in the case of an earthquake, research that integrates road blockades into evacuation simulations is quite limited. From that viewpoint, this research aims to develop evacuation modeling with consideration of road blockades to simulate how residents move to evacuation centers (hereafter, shelters) through urban areas following an earthquake occurrence. The research also determines difficulties that residents may encounter under earthquake conditions, compared with normal conditions, corresponding to considering or not considering road blockades, respectively, such as having no access to shelters, taking longer routes instead of shortest routes, and so on. Debris from damaged buildings in an urban area is assumed as the main source of debris that would cause a road blockade. The model is applied to a case study of the Daitoku school district in Kanazawa city. According to simulated results, due to road blockades, occupants of many damaged buildings did not have access to shelters, and a lot of evacuees needed to move to shelters with longer routes instead of taking the shortest routes. Furthermore, the research results show the possibility of considering road blockades for improving current evacuation modeling and making evacuation simulations more realistic.

Occupant evacuation elevators as a measure for crowd management and evacuation for people with mobility impairments in high‐rise buildings

AbstractFire evacuation in high‐rise buildings has difficulties owing long‐distance descent with few staircases, long evacuation times, and the congestion of evacuees. Additionally, evacuation measures for the elderly and people with mobility impairments are required. To solve these problems, an evacuation strategy in which able‐bodied people and people with mobility impairments evacuate together with standard passenger elevators (EVs) without discrimination was proposed in this study. This strategy exploits typical architectural and EV configurations optimally designed for main building functions and daily transportation demands. The feasibility of this strategy was discussed through case studies of large‐area rental office‐type and mixed‐use high‐rise buildings. At a fire floor, to avoid excessive dependence on the boarding control of emergency service personnel, intensive EV service was proposed. By reducing the waiting time, evacuees are expected to be sober‐minded when entering the EVs or staying on the floors. For the evacuation of the non‐fire floors, the EV capacities are insufficient. In this case, able‐bodied evacuees are encouraged to use the staircases, and occupants in the other zones are encouraged to wait or evacuate with EVs to prevent merging in the staircases. This guiding method using signage and voice alarm system was also discussed.

Simulation study on pedestrian evacuation optimization in a multi-exit building

Two multi-exit selection models based on social force model are presented to simulate pedestrian evacuation, and the model coefficients are optimized by considering the effect of the exit distance, exit width, crowd number and distribution. The evacuation processes employing shortest distance evacuation strategy, static and dynamic exit selection model are compared. The effects of the crowd number, distribution and desired speed are investigated on the evacuation time and balance degree with the static and dynamic exit selection model. The effects of group size and group shape on the evacuation time in dynamic exit selection model is explored. The simulation results indicate that the proposed dynamic exit selection model can realistically reflect the pedestrian evacuation and help predicate the time available in building spaces with multiple exits, which can lead to a shorter evacuation time and higher evacuation efficiency. The study has some guiding significance for emergency evacuation and exits design of multi-exit buildings.

Assessing and zoning of typhoon storm surge risk with a geographic information system (GIS) technique: a case study of the coastal area of Huizhou

Abstract. Storm surge is one of the most destructive marine disasters to life and property for Chinese coastal regions, especially for Guangdong Province. In Huizhou city, Guangdong Province, due to the high concentrations of chemical and petroleum industries and the high population density, the low-lying coastal area is susceptible to the storm surge. Therefore, a comprehensive risk assessment of storm surge over the coastal area of Huizhou can delimit zones that could be affected to reduce disaster losses. In this paper, typhoon intensity for the minimum central pressure of 880, 910, 920, 930, and 940 hPa (corresponding to a 1000-, 100-, 50-, 20-, and 10-year return period) scenarios was designed to cover possible situations. The Jelesnianski method and the Advanced Circulation (ADCIRC) model coupled with the Simulating Waves Nearshore (SWAN) model were utilized to simulate inundation extents and depths of storm surge over the computational domain under these representative scenarios. Subsequently, the output data from the coupled simulation model (ADCIRC–SWAN) were imported to the geographic information system (GIS) software to conduct the hazard assessment for each of the designed scenarios. Then, the vulnerability assessment was made based on the dataset of land cover types in the coastal region. Consequently, the potential storm surge risk maps for the designed scenarios were produced by combining hazard assessment and vulnerability assessment with the risk matrix approach. The risk maps indicate that due to the protection given by storm surge barriers, only a small proportion of the petrochemical industrial zone and the densely populated communities in the coastal areas were at risk of storm surge for the scenarios of 10- and 20-year return period typhoon intensity. Moreover, some parts of the exposed zone and densely populated communities were subject to high and very high risk when typhoon intensities were set to a 50- or a 100-year return period. Besides, the scenario with the most intense typhoon (1000-year return period) induced a very high risk to the coastal area of Huizhou. Accordingly, the risk maps can help decision-makers to develop risk response plans and evacuation strategies in coastal communities with a high population density to minimize civilian casualties. The risk analysis can also be utilized to identify the risk zones with the high concentration of chemical and petroleum industries to reduce economic losses and prevent environmental damage caused by the chemical pollutants and oil spills from petroleum facilities and infrastructures that could be affected by storm surge.

Analysis of human behavior in case of fire inside a high-rise building: effect of risk perception and Individual's location

PurposeThe main purpose of this research is to achieve the evacuation strategy of people in high-rise office buildings. This purpose is achieved by identifying the individuals' behaviors during a fire accident and the relationship between these behaviors and their risk perception.Design/methodology/approachThe method of this study is mixed-methods type. The first stage was carried out using the qualitative method and descriptive phenomenology and the analyses were done using the Colaizzi method, and the second stage was carried out using the quantitative method of field descriptive survey type whose analyses were conducted through SPSS software.FindingsThe results reveal that the individuals attempting evacuation from the upper floors above the fire level were mostly injured and the ones who remained in the building and got help from fire fighters were rescued. At the end, the study goes on to suggest the stay-in-place approach with regards to the behaviors formed in individuals, closed plan of architectural design, lack of suitable fire extinguishers as well as inappropriate individual trainings.Research limitations/implicationsLack of similar research in the field of fire in Iran caused bottlenecks such as lack of cooperation of relevant organizations in the path of the research. Another factor that limited the present research was the determination of people trapped in fire. In this case, those who were present in the incident had to be chosen and the questionnaire was completed based on their opinions. This limited the research for reasons such as the relocation of some people from buildings or their death.Practical implicationsThe practical results of this research can be used in reviewing the rules and regulations of high-rise building fire code. By properly compiling the regulations of high-rise building codes based on this research, human injuries in fire hazards can be greatly prevented. Due to the collapse of the Plasco building in Iran and the creation of inappropriate memories in the minds of people of high-rise buildings, with the construction of buildings based on the rules and regulations in accordance with the fire code, the construction market as well as the sale and purchase of such buildings will flourish and numerous financial and job turnovers are created in the field of this type of buildings.Originality/valueThis study is innovative in determining appropriate evacuation strategy that are related to the individuals' risk perception in high-rise buildings, as well as achieving results to review the rules and regulations of high-rise office buildings based on the high-rise building fire code.

Development of a radiological emergency evacuation model using agent-based modeling

In order to mitigate the damage caused by accidents in nuclear power plants (NPPs), evacuation strategies are usually managed on the basis of off-site effects such as the diffusion of radioactive materials and evacuee traffic simulations. However, the interactive behavior between evacuees and the accident environment has a significant effect on the consequential gap. Agent-based modeling (ABM) is a method that can control and observe such interactions by establishing agents (i.e., the evacuees) and patches (i.e., the accident environments). In this paper, a radiological emergency evacuation model is constructed to realistically check the effectiveness of an evacuation strategy using NetLogo, an ABM toolbox. Geographic layers such as radiation sources, roads, buildings, and shelters were downloaded from an official geographic information system (GIS) of Korea, and were modified into respective patches. The dispersion model adopted from the puff equation was also modified to fit the patches on the geographic layer. The evacuees were defined as vehicle agents and a traffic model was implemented by combining the shortest path search (determined by an A ∗ algorithm) and a traffic flow model incorporated in the Nagel-Schreckenberg cellular automata model. To evaluate the radiological harm to the evacuees due to the spread of radioactive materials, a simple exposure model was established to calculate the overlap fraction between the agents and the dispersion patches. This paper aims to demonstrate that the potential of ABM can handle disaster evacuation strategies more realistically than previous approaches.

Adequately reflecting the severity of tropical cyclones using the new Tropical Cyclone Severity Scale

For decades, meteorologists and governments have been warning communities in coastal areas for an imminent tropical cyclone (TC) using the Saffir-Simpson Hurricane Wind Scale (SSHWS). The SSHWS categorizes a TC based on its maximum wind speed, and is used in defining evacuation strategies and humanitarian response. However, the SSHWS considers only the wind hazard of a TC, whereas a TC can also cause severe conditions through its high storm surges and extreme rainfall, triggering coastal and inland flooding. Consequently, the SSHWS fails to mirror the TC’s total severity. This becomes evident when looking at past events such as Hurricane Harvey (2017), which was classified as a Tropical Storm while it caused widespread flooding in the Houston (TX) area, with precipitation totals exceeding 1.5 m. Without including storm surge and rainfall information, adequate risk communication with the SSHWS can be challenging, as the public can (mistakenly) perceive a low-category TC as a low-risk TC. To overcome this, we propose the new Tropical Cyclone Severity Scale (TCSS) that includes all three major TC hazards in its classification. The new scale preserves the categorization as used in the SSHWS, to maintain familiarity amongst the general public. In addition, we extend the scale with a Category 6, to support communication about the most extreme TCs with multiple hazards. The TCSS is designed to be applied on a local-scale, hereby supporting local-scale risk communication efforts and evacuation strategies prior to a TC landfall. The scale can be used for risk communication on both the total TC risk and on the categories of the separate hazards, which can be valuable especially in cases when one hazard is the predominant risk factor, such as excess rainfall triggering flooding.