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Based on surveys and interviews conducted in 2020 and 2021, this article explores perceptions and preparations regarding volcanic risk in Guadeloupe. Although adaptive strategies have evolved since the last eruptive crisis in 1976, the study reveals widespread ignorance of evacuation procedures, reveals the ineffectiveness of a top-down management approach, and reveals citizens' distrust of their government. To strengthen their preparedness for future eruptive crises, it is necessary to explore avenues for improvement in this context.

Continuous improvement in computing power allowed for an increase of the scales micro-traffic models can be used at. Among them, agent-based frameworks are now appropriate for studying ordinary traffic conditions at city-scale, but remain difficult to adapt, especially for non-computer scientists, to more specific application contexts (e.g., car accidents, evacuation following a natural disaster), that require integrating particular behaviors for the agents. In this paper, we present a built-in model integrated into the GAMA open-source modeling and simulation platform, allowing the modeler to easily define traffic simulations with a detailed representation of the driver's operational behaviors. In particular, it allows modelling road infrastructures and traffic signals, change of lanes by driver agents and less normative traffic mixing car and motorbike as in some South East Asian countries. Moreover, the model allows to carry out city-level simulations with tens of thousands of driver agents. An experiment carried out shows that the model can accurately reproduce the traffic in Hanoi, Vietnam.

This paper offers a reflection on the constraints imposed by the focus of the management of the pandemic at the global level and of the epidemic at the level of the territories on the preparation and anticipation of new threats, such as natural hazards.

As part of the ESCAPE research program on mass evacuation strategies for population in crisis management, we carried out a survey in the Rouen agglomeration in 2018. This survey focused on knowledge of the warning signal and safety instructions in populations exposed to industrial risk during the day. The accident at the Lubrizol factory on September 26, 2019 gives acuity to certain results of this study which may shed light on the current debate on methods of alerting, transmitting safety instructions and protecting populations.More than 70% of those questioned do not know the national warning signal emitted by sirens and almost 60% do not know the instructions associated with it in the context of an industrial accident. This lack of knowledge would translate into a variety of reflex reactions in the event of an alert being triggered, ranging from indifference to flight, while awaiting additional information. Non-resident populations and tourists have the lowest levels of knowledge of industrial risk safety instructions. When they are known, the instructions are interpreted differently and followed according to the means of travel used by the people at the time of the survey. For the motorist, the abandonment of the vehicle raises many questions and encourages him to continue his journey or flee the area. For the pedestrian, finding shelter can be a real challenge in an urban environment. The vast majority of security personnel and facility managers we interviewed said that they would not allow people into their facility in the event of an alert. The following suggestions for improvement can thus be proposed: (i) a more regular preventive information policy which affects the entire population attending and not only residing in an area at industrial risk, (ii) multi-channel warning and communication means to inform the populations present in a danger zone and (iii) stronger involvement of establishments welcoming the public and their staff in keeping people safe. These three components are elements to be initiated or reinforced to reduce the exposure and vulnerability of populations faced with an industrial accident.

Human mobilities in urban areas have an impact on the spread of infectious diseases, including those caused by mosquito-borne diseases like dengue and Zika virus. Therefore, finding appropriate data and methods to perform spatial analyses of mobilities is a critical issue. The emergence of substantial amount of geolocated data, which is easily available on the Internet, has a great potential in mobility researches, especially when paired with land use, following the activity-space concept. This paper, focused on the dengue endemic mega-city of Bangkok (Thailand), explores the potentialities of (A) using a land use classification from Google’s points of interest (POIs) to assess the likelihood of performing an activity from (B) a large dataset of individual geolocated tweets to characterize and quantify daily mobility. These emerging data sources allow the characterization of (C) the rhythms of daily mobility in Bangkok, from the perspective of (1) the macroscopic urban pulse and (2) the rhythms and aims for individual movement. The advantages and limitations of this kind of data will be finally discussed regarding dengue epidemics.

Escape-SG is a simulator project inspired by serious games. It will immerse the trainees in realistic situations of potentially major crises requiring the evacuation of populations. Developed for and with crisis management actors, these scenarios will aim to assess their knowledge of procedures, improve their interaction and communication skills within crisis cells and prepare them to manage major events that may involve massive population displacement. Developed to operate on a touch table, this simulator will be integrated into crisis management simulation rooms where it will make an important contribution considering complex social dynamics in the scenarios proposed.

In order to fight against the transmission of dengue, yellow fever, chikungunya and Zika viruses, significant resources were allocated to the process of restricting the propagation of their main vector, the Aedes aegypti mosquito. Research on this mosquito’s living areas is thus necessary to characterize more precisely the areas that need to be monitored and treated. An alternative to field surveys consists of evaluating the characteristics of these living areas through spatialized models. It is in this context that we developed the simulation model MOMA (Model Of Mosquito Aedes aegypti), an agent-based model which integrates a vast set of biological and behavioral knowledge about the mosquito in a simulation environment based on the needs and constraints specific to Aedes aegypti. In this paper, we present MOMA and a study of the effects of local configurations on the dispersion capacity of mosquito cohorts. The simulations in this study were carried out using data from an urban neighborhood in the city of Delhi (India). This virtual laboratory, constructed in collaboration with entomologists, thus makes it possible to represent the mosquito’s living areas, which are either restricted or facilitated by spatial amenities conditioning its needs and its capacity of movement during its lifetime.Keywords: dengue, health, agent-based model, risk, urban area, modeling/modelling

In order to fight against the transmission of dengue, yellow fever, chikungunya and Zika viruses, significant resources were allocated to the process of restricting the propagation of their main vector, the Aedes aegypti mosquito. Research on this mosquito’s living areas is thus necessary to characterize more precisely the areas that need to be monitored and treated. An alternative to field surveys consists of evaluating the characteristics of these living areas through spatialized models. It is in this context that we developed the simulation model MOMA (Model Of Mosquito Aedes aegypti), an agent-based model which integrates a vast set of biological and behavioural knowledge about the mosquito in a simulation environment based on the needs and constraints specific to Aedes aegypti. In this paper, we present MOMA and a study of the effects of local configurations on the dispersion capacity of mosquito cohorts. The simulations in this study were carried out using data from an urban neighbourhood in the city of Delhi (India). This virtual laboratory, constructed in collaboration with entomologists, thus makes it possible to represent the mosquito’s living areas, which are either restricted or facilitated by spatial amenities conditioning its needs and its capacity of movement during its lifetime.

BACKGROUND:This study has been conducted to throw light on the knowledge and practices related to dengue fever among the poor population living in Delhi's slums. MATERIALS:A household survey was conducted in 2013 among 3,350 households. The households were stratified by a number of variables related to socio-economic status and health events such as hospitalisation. The data collection was completed through face-to-face interviews conducted with the help of 25 field investigators. RESULTS:About 8% of the households had at least one diagnosed dengue case. In comparison to the population surveyed, teenagers (15-19 years) and adults (30-34 years) were more affected whereas children under four years of age were underrepresented. Housewives are more affected by dengue (24%) compared to their share of the population surveyed (17%). Despite the fact that 77% of the respondents are worried about mosquitoes, only 43% of them monitor environment to avoid the presence of breeding sites. CONCLUSION:One cannot exclude the possibility that though young children under the age of four years are exposed to the virus, either their cases were asymptomatic or family members infected during this period had potentially more serious symptoms leading to hospitalisation. This result could thus be explained by budget-related health choices made by this population which do not favour small children. Educational programs should target housewives to improve their impact, as they are the ones mostly responsible for water storage and cleanliness of the house and its neighbourhood. Even with a dengue experience and potentially an acute perception of the risk and its factors, a proper management of environmental conditions is lacking. This along with the fact that word-of-mouth is the main source of information quoted should be a message for municipality health workers to give door-to-door information on how to prevent breeding sites and dengue infection.

This paper presents MAGeo (Modeling Agent in Geography), a user-friendly agent-based simulation tool dedicated to spatialized and multilevel researches. Model development with MAGeo does not require any particular programming skills. The conceptual model is realized through graphical objects, such as boxes and links to organize them. Model's ontology is based on the following three entities: Agent - Organization - Behavior that allow the building of multilevel model. The modeler has access to the simulation window in order to develop its model's dynamic. Simulation model is built using cursors and other graphical tools to parametrize the model, as well as maps and graphs to explore the model's behavior. MAGeo is readily accessible to social scientists which aim to develop spatialized and complex models but don’t possess programming skill. Because learning MAGeo and developing model is not time-consuming, MAGeo is also well designed for teaching complex system. Finally, its graphical approach produces perfect systemic and multilevel graphics for communication in multidisciplinary teams.

This paper introduces the surveillance and fight against dengue fever in India. On one side, it presents the national control and surveillance system and on the other, the daily perceptions of the habitants and the local actors of Delhi (India). There are several issues to overcome between the low self-fulfilling prophecies of the public health guidelines and the field reality. India will continue to face several epidemics of dengue until some active policies by the States of the Union and a strong multi-sectoral approach of health issues at urban scale-level are brought in place.

Complexity theories focus on the interactions between entities in systems. Each entity of a complex system is organised in sub-levels and parallel levels interacting together in different ways. In geography, micro-level studies considering the spatial dynamic of epidemics as complex systems are quite rare. From a set of studies based on the analysis of the HIV/ AIDS epidemic in Mumbai (Bombay, India) and on the multi-agent based modelling of an epidemic, this paper explores several types of complexity : of levels, of the quantity of entities, and of the dynamics in non linear systems. First, we analyse the transition phases in a spatial diffusion process and the impact of circulation networks in the emergence of an epidemic. Second, we propose a new approach in the modelling of the spatial diffusion of an epidemic by combining both heterogeneity of space and patterns of mobility.

Industrial accidents are a major risk in many countries. Despite this observation, effective preventive action is not being developed and studies of the behaviors of vulnerable populations remain under-explored. According to safety instructions, residents must take shelter and remain indoors but other behaviors may be observed such as: running away from the affected area, panicking, or following people around. In order to assess the attitudes of people and the effects of local contingencies that could interfere with official advice in the event of a toxic cloud, a specific agent-based model called TOXI-CITY has been developed. The aim of this explorative model is to determine whether a minimum number of well-informed agents (i.e. those who follow the emergency protocol) can save a maximum number of uninformed and impressionable ones. Simulations indicate that the initial number of agents and the spatial configuration of the grid strongly influence final survival rates. A non-linear pattern emerged: survival rates increase when well-informed agent rates are low (below 30%) while increasing the percentage of informed agents (from 70%) seems to improve only slightly the chances of survival.

The appearance of S-curve in the treatment of a space-time data is very often associated to a spatial diffusion. This systematic assimilation of the S-curve to the logistic model is misleading, , it leads to an amalgam which masks the diversity of mathematical models to capture really different phenomena of diffusion.The aims of this paper is to show some examples of diffusion which are all expressed by a S-curve but which correspond in fact to different models. Three models are presented:- logistic model is the most usually used by geographers despite his independency from space. We compare here a spatialized and probabilistic version of this model with its analytical and deterministic form.- as opposed to the first one, the front diffusion model imposes a strong space constraint, the contact being prevalent in the diffusion. In this case, diffusion is not subjected to a global constraint but depends on the length and on the form of the front at any moment.- the third model is composite, it proceeds of the logistic growth forced by local constraints and of propagation of a front.These three models are studied in their analytical forms and are compared with their dynamic simulated. We show a continuity between these 3 models entering within the framework of a broader class of parameterized models. Moreover their combinations give an expansion of other models making it possible to apply to a great variety of problems.

The question of complexity and its increasing application to social sciences is challenging the modelling of spatial systems. New concepts and new methods have been proposed and invite to reformulate classical modelling frames. This approach demands to open a better-informed dialogue between the disciplines which supply models and tools and those where the existing knowledge is reformulated inside this new frame. Creating an « artificial geography » is not straightforward. It is rather easy to translate urban theories within the paradigm of complex systems, but their modelling, for instance by using multi-agent systems, still raises many conceptual and practical difficulties. We underline here some problems in defining significant urban entities and exploring the evolution of their spatial relationships over time. We briefly present which options have been selected for developing the SIMPOP2 model which is conceived to simulate the evolution of systems of cities over long periods of time.

This paper presents the main contributions of an agent-based approach for modelling and simulating the processes of diffusion in geographical space. This approach is compared with the macro modelling traditionally employed to describe such phenomenons. The logistic model is thus presented as representative of this category of model. The agent-based models represent a possible alternative to a macroscopic approach of the processes of diffusion. Related to the theories of self-organization, it is assumed that the phenomena observed on a certain level are the result of the many interactions which occur on one or more lower levels. As a simulation tool predisposed to the analysis of such a dynamic, the multi-agent systems are briefly presented. This paper ends with a brief example of application, the modelling and the simulation of the diffusion of an agricultural innovation model (Hägerstrand's model revisited).

In France, since June 2022, the prefectural authorities are capable to send a cell-broadcasted notification on mobile phones to all people located in a danger zone, using the platform so-called FR-Alert®. While numerous studies have demonstrated that this notification must be clear, precise and formulated with simple words, to be understood by the greatest number of people, no study has ever been carried out to evaluate the content of the notifications and to compare them with the state of the art. To fill this gap, a grid has been applied to notifications sent during drills (n=100) or real alerts (n=29), collected between May 2022 and February 2024. This allowed to calculate the frequency of the elements present and to valuate an overall score. The main results show that most of the messages followed the state of the art (73% of messages scored above average); some messages deviated significantly from the normative framework and were therefore problematic; the omitted elements are related to the timing and an internet link required to authenticate the alert sender; the increase in the number of exercises for several prefectures and over time have no effect on the score, which raises the question of the transfer of knowledge towards operational staff and the possibility of improving the platform.

Dengue fever is an urban, tropical, and semi-tropical disease transmitted by Aedes aegypti and Aedes albopictus mosquitoes. One significant challenge lies in identifying reliable intra-urban indicators of their densities. Following standardized sampling protocols that adequately take into account the spatial heterogeneity of the geographical contexts which may influence mosquito habitats is therefore fundamental to compare studies and follow such relevant indicators. We develop a method for subdividing urban territory based on environmental factors which are susceptible to influence the density of potential mosquito-breeding containers. Indeed, the presence of these containers, most of which are produced by humans, is essential for the renewal of mosquito populations. Land-uses variables and their local variations are determinant in this analysis. Starting from each building and its immediate neighborhood described in terms of vegetation and open area, we computed the local landscape metrics of a million buildings in Bangkok. We then used segmentation and clustering techniques to generate homogeneous zones based on these components and physiognomy. Subsequently, a classification process was conducted to characterize these zones according to land-use and composition indicators. We applied this automatic clustering method within Bangkok’s urban area. This classification built from hypotheses on the existence of links between the types of urban landscape and the presence of outdoor containers must be evaluated and will serve as a foundation for the spatial sampling of field studies for vector surveillance in Bangkok. The choice of sampling zones, even if it must be based on an administrative division due to the decentralization of health agencies in Bangkok, can then be enriched by this new, more functional division. This method, due to the genericity of the factors used, could be tested in other cities prone to dengue vectors.

BACKGROUND:Dengue is a major international public health concern, one of the most important arthropod-borne diseases. More than 3.5 billion people are at risk of dengue infection and there are an estimated 390 million dengue infections annually. This prolific increase has been connected to societal changes such as population growth and increasing urbanization generating intense agglomeration leading to proliferation of synanthropic mosquito species. Quantifying the spatio-temporal epidemiology of dengue in large cities within the context of a Geographic Information System is a first step in the identification of socio-economic risk factors. METHODOLOGY/PRINCIPAL FINDINGS:This Project has been approved by the ethical committee of Institut Pasteur. Data has been anonymized and de-identified prior to geolocalisation and analysis. A GIS was developed for Delhi, enabling typological characterization of the urban environment. Dengue cases identified in the Delhi surveillance system from 2008 to 2010 were collated, localised and embedded within this GIS. The spatio-temporal distribution of dengue cases and extent of clustering were analyzed. Increasing distance from the forest in Delhi reduced the risk of occurrence of a dengue case. Proximity to a hospital did not increase risk of a notified dengue case. Overall, there was high heterogeneity in incidence rate within areas with the same socio-economical profiles and substantial inter-annual variability. Dengue affected the poorest areas with high density of humans, but rich areas were also found to be infected, potentially because of their central location with respect to the daily mobility network of Delhi. Dengue cases were highly clustered in space and there was a strong relationship between the time of introduction of the virus and subsequent cluster size. At a larger scale, earlier introduction predicted the total number of cases. CONCLUSIONS/SIGNIFICANCE:DENV epidemiology within Delhi has a forest fire signature. The stochastic nature of this invasion process likely smothers any detectable socio-economic risk factors. However, the significant finding that the size of the dengue case cluster depends on the timing of its emergence emphasizes the need for early case detection and implementation of effective mosquito control. A better understanding of the role of population mobility in contributing to dengue risk could also help focus control on areas at particular risk of dengue virus importation.