Flood Risk Communication Research Articles

Integrating Intelligent Hydro-informatics into an effective Early Warning System for risk-informed urban flood management

The urban drainage system constantly facing flooding issues in coastal and urban areas. Robust and accurate urban flood management, particularly considering fast-moving compound floods, is crucial to minimize the impact of flood disasters in coastal cities. Till now, Ho Chi Minh City (HCMC) lacks an effective means of urban flood management because of flood risk communication among residents. Existing flood risk communication tools rely on post-disaster flood model outcomes and data. Therefore, this research proposes a real-time Early Urban Flooding Warning System (EUFWS) integrated with a user-friendly web and app interface. The backbone of this system consists of flood models developed using machine learning (ML) algorithms, combined with big data and Web-GIS visualization, with ML serving as the core for constructing the EUFWS. EUFWS offer several key advantages: they are available at all times, accessible from anywhere, and provide a real-time, multi-user working platform. Additionally, the system is flexible, allowing for the easy addition of components and services and scalable, adjusting to workload demands. EUFWS have been successfully deployed in Thu Duc City, Vietnam, as a case study and are operating effectively. EUFWS have been successfully deployed in Thu Duc City, Vietnam, as a case study and are operating effectively. Research results indicate that EUFWS supported decision-makers to be effectively risk informed and make intelligent decisions during urban flood emergencies. This underscores the significant potential of integrating ML and information technology to enhance the management of smart urban drainage systems in flood-prone cities worldwide.

Community flood risk assessment in selected areas in Muntinlupa City

The study's objective is to hopefully create a profound awareness in the city government of Muntinlupa of the plight the community is experiencing. A quantitative research design was utilized in this study. Flood risk perception: The probability of whether a retention pond, increasing the diameter of the existing reinforced concrete pipes, and or increasing the road elevation can be a permanent or a quick-fix solution is still unknown until the local government can conduct a comprehensive technical and environmental assessment of the different vulnerability factors in the community. No significant differences were found between age, years of residency, and flood risk perception. Flood risk preparedness: No significant differences existed between age, years of residency, and flood risk preparedness. Substantial differences were found between gender and flood preparedness, and they favor the male gender. Flood risk awareness: No significant differences existed between age, years of residency, and flood risk awareness. There were substantial differences between gender and flood awareness, and they favored the male gender. The study's recommendations encourage the local government of Muntinlupa to conduct a comprehensive administrative, technical, and environmental assessment of the different vulnerability factors facing the selected areas in the community.

Investigating the influence of information sources on flood-coping appraisal: Insights into flood mitigation behaviour

Understanding how individuals and communities respond to flood risks is paramount for effective disaster management and community resilience. This study investigates the impact of information sources on the coping appraisal of Australian flood-prone communities (flood-coping appraisal) to gain insight into flood mitigation behaviour. Utilizing the cognitive process of Protection Motivation Theory (PMT) and integrating it with the Health Belief Model (HBM), a comprehensive framework is developed to explore the interplay between sources of information, cognitive appraisals, and coping responses. Using Partial Least Squares Structural Equation Modeling (PLS-SEM), data from a research survey are analysed to examine the relationships between latent variables within the framework. The results reveal two key components significantly affecting flood-coping appraisal: Benefit/barrier Appraisal and Social Environment. Benefit/barrier Appraisal evaluates individuals' perceptions of the cost-effectiveness of mitigation measures, their potential impacts on property appearance, and property resale value, while the Social Environment assesses individuals’ observational learning from social norms and the availability of social support. Additionally, experiences with floods inside buildings emerge as a significant factor influencing the flood-coping appraisal. The findings underscore the importance of understanding the sources of information that drive higher flood-coping appraisal for effective flood risk management and community resilience. These insights contribute to developing targeted flood risk communication strategies to promote adaptive behaviours and enhance community resilience in the face of flood hazards.

How health risk communication best practices can improve community flood risk communication

How health risk communication best practices can improve community flood risk communication

Physics-based flood vulnerability assessment for steel portal framed industrial buildings

Steel portal framed industrial buildings have been widely used as warehouses, supermarkets, manufacturing workshops and storage facilities around the world. As such, these buildings make up a significant portion of the building stock. Despite this, there remains a lack of the physics-based flood vulnerability models necessary for undertaking detailed community flood risk management activities (e.g., quantitative risk assessment, cost-benefit analysis of risk reduction and resilience enhancement measures at the building level). To this end, this study developed a physics-based vulnerability assessment method for steel portal framed industrial buildings subjected to hydrostatic and hydrodynamic flood actions. Physical damage induced by flood forces to the building envelope (wall siding and fenestration) and the structural framing (steel portal frames and end wall frames) was considered. Monte Carlo simulations incorporate various flood load cases, probability models of demands and capacities as well as major failure mechanisms of different structural and non-structural components to conduct the damage assessment. The flood vulnerabilities for a prototype industrial building link the physical damage of individual building subassemblies to monetary loss ratios considering various inundation depths, flow velocities and flow directions.

Tweeting Through the Flood: Application of BERT Topic Modeling for a Comparative Flood Communication Analysis

Floods are prevalent disasters in the United States, posing escalating risks due to climate change-induced factors like rising sea levels and erratic rainfall patterns. Despite governmental efforts, flood risk communication remains inadequate, hindering preparedness and response capacity. While governmental agencies predominantly employ traditional, one-sided information dissemination approaches, social media platforms pose as crucial early warning indicators and sources of real-time information. This study conducts the first part of our intended comparative analysis of social media messages between governmental agencies and communities. We perform a case study on a flooding event in Michigan from May 17-20, 2020. Utilizing advanced topic modeling, we examine Twitter/X message content and sentiment from community-based posts. Insights aim to inform more effective flood communication strategies, bridging the gap between official information and community needs during events. Future work will compare social media messages' content and sentiment from governmental agencies relative to those from the community.

Server-enabled mixed reality for flood risk communication: On-site visualization with digital twins and multi-client support

This study introduces a novel mobile mixed reality (MR) system to improve communication among stakeholders regarding climate-change-driven flood risk. This MR system enables stakeholders to visualize flood risks on common mobile devices, such as smartphones and tablets, offering perspectives from their respective environments. The system overcomes the computational limitations of previous mobile MR systems by rendering the MR images on a server. Furthermore, distributing users across multiple servers enables many users to simultaneously perform server-enabled MR, facilitating widespread engagement in flood risk communication. The system uses a viewport transformation to accurately display virtual floods and correct for real-time posture changes. A prototype tested in a high-risk flood area achieved real-time MR visualization at more than 16 frames per second, even on multiple devices. Future research will aim to promote stakeholder participation through more accurate visualization of virtual floods and improved interactive information sharing among users.

Proposing Thematic Mapping for Integrated Risk Communication: A study of British & Japanese perspectives in flood-prone communities

Modern flood risk communication continues to lack the input of different stakeholder levels and as a result, there has been an insufficiency to construct communication that is inclusive of all stakeholders. There is also still an absence of consideration of context-specific information that helps to shape the communication crafting process. This study sought to establish the above through the creation of a thematic map (a visual display based on themes), merging top-down and bottom-up approaches to create a clearer picture of important factors for risk communication within the specific contexts being observed. The research team conducted 16 semi-structured interviews and focus groups with 4 different types of stakeholders at 2 rural sites in the UK and 2 rural sites in Japan. The results outlined five key themes that underpin integrated risk communication, establishing the thematic map – Individual Circumstances, Community Structure, Impact Scale, Response Capacity, and Social Barriers. These findings are important in beginning to help conceptualise how current DRR efforts can be enhanced and in presenting an integrated approach to risk communication that helps to reduce unnecessary complexity and inaccessibility. However, further replications of the study are needed at other sites across the world to test the robustness and adaptability of this kind of modelling.

Development of a virtual flood experience system and its suitability as a flood risk communication tool

Development of a virtual flood experience system and its suitability as a flood risk communication tool

Factors of influence on flood risk perceptions related to Hurricane Dorian: an assessment of heuristics, time dynamics, and accuracy of risk perceptions

Abstract. Flood damage caused by hurricanes is expected to rise globally due to climate and socio-economic change. Enhanced flood preparedness among the coastal population is required to reverse this trend. The decisions and actions taken by individuals are thought to be influenced by risk perceptions. This study investigates the determinants that shape flood risk perceptions and the factors that drive flood risk misperceptions of coastal residents. We conducted a survey among 871 residents in flood-prone areas in Florida during a 5 d period in which the respondents were threatened to be flooded by Hurricane Dorian. This approach allows us to assess temporal dynamics in flood risk perceptions during an evolving hurricane threat. Among 255 of the same households, a follow-up survey was conducted to examine how flood risk perceptions varied after Hurricane Dorian failed to make landfall in Florida. Our results show that the flood experience and social norms have the most consistent relationship with flood risk perceptions. Furthermore, participants indicated that their level of worry regarding the dangers of flooding decreased after the near-miss of Hurricane Dorian compared to their feelings of worry during the hurricane event. Based on our findings, we offer recommendations for improving flood risk communication policies.

Short-term panel data analysis of the effect of flood risk communication on individual evacuation decisions

People-centered risk communication is important to mitigate the flood damage caused by the recent increase in heavy rainfall events in Japan. Longitudinal studies are particularly important for evaluating the effectiveness of risk communication methods; however, current research is insufficient. To address this gap, we conducted a longitudinal study, specifically through four panel surveys conducted over a short period, to investigate the effects of various risk communication methods such as running an evacuation simulation to learn about flood damage, providing information about the evacuation behavior of others, and distributing hazard maps. The results of a fixed effects analysis of the panel data suggest that the impact of risk communication depends on the initial evacuation attitude. In particular, we find that distributing hazard maps had a negative effect on the evacuation behavior of those who initially responded that they would evacuate. This suggests that residents in non-flood-prone areas may have acquired the correct hazard perception from these hazard maps. However, for those who initially chose not to evacuate, receiving the distributed content had a positive effect on their evacuation behavior 12 h before the typhoon hit. This suggests that those who initially chose not to evacuate may have reconsidered their decision. The findings of this study may help future risk communication by reducing congestion at evacuation sites due to excessive evacuation, while increasing the evacuation rate of those who should evacuate.

A 3D virtual geographic environment for flood representation towards risk communication

Risk communication seeks to develop a shared understanding of disaster among stakeholders, thereby amplifying public awareness and empowering them to respond more effectively to emergencies. However, existing studies have overemphasized specialized numerical modelling, making the professional output challenging to understand and use by non-research stakeholders. In this context, this article proposes a 3D virtual geographic environment for flood representation towards risk communication, which integrates flood modelling, parallel computation, and 3D representation in a pipeline. Finally, a section of the Rhine River in Bonn, Germany, is selected for experiment analysis. The experimental results show that the proposed approach is capable of flood modelling and 3D representation within a few hours, the parallel speedup ratio reached 6.45. The intuitive flood scene with 3D city models is beneficial for promoting flood risk communication and is particularly helpful for participants without direct experience of floods to understand its spatiotemporal process. It also can be embedded in the Geospatial Infrastructure Management Ecosystem (GeoIME) cloud application for intelligent flood systems.

Restoring with risk: perceptions of reservoir flood risk in Whaley Bridge

Understanding flood risk perceptions is critical for effective flood risk communication. In 2019, the failure of Toddbrook Reservoir's spillway resulted in a severe flood warning being issued in the Whaley Bridge area. In 2022, a large-scale restoration began at the reservoir. This paper describes perceptions of reservoir flood risk by the residents of Whaley Bridge and experts in environmental science and engineering. Results show that risk perception varies, with residents perceiving reservoir flood risk subjectively and experts perceiving risk objectively. With no previous risk communication, residents did not consider there to be a risk of reservoir failure; moreover, they have trust in Toddbrook's restoration. Experts emphasize that risk can never be fully eliminated, but that the probability of failure is extremely low. Some considered climate change as a contributing factor to the event and uncertainties in the risks it poses brings a requirement to improve and maintain existing dams. Findings have demonstrated the importance of improved risk communication and a necessity to improve flood risk maps for accessibility, awareness and to better account for probability of failure to avoid misinterpretation of risk. By identifying differing perceptions of risk between experts and residents, better reservoir risk communication can be achieved.

Toward a New Flood Assessment Paradigm: From Exceedance Probabilities to the Expected Maximum Floods and Damages

AbstractTo assess flood risks, we seek to estimate the probability distribution of the worst possible single‐event over a contiguous period of N years rather than the cumulative losses expected over a planning horizon. For this we use the probability distribution FN of extreme flood events over a multi‐year period, which is different from using the conventional single‐valued exceedance probability of 1/N years. FN can be used to estimate the hazard and then proceed to the estimation of risk, which we define as the “largest expected damage” over the set period. It also allows for a more coherent determination of design values, which descend from fully acknowledging the aleatoric uncertainty of the underlying natural river flow process. The epistemic uncertainty is removed by marginalizing the aleatoric‐epistemic uncertainty joint distribution over the parameter space. The advantage of the proposed Bayesian approach, which can be summarized in 12 steps, is demonstrated for the 2021 River Ahr flood in Germany, which caused casualties and huge material damage. Adopting the multi‐year maxima extreme value distribution can potentially lead to the reclassification of vulnerability levels for flood‐prone areas and reconsideration of current policy‐making and flood risk communication.

Fatal incidents during the flood of July 2021 in North Rhine-Westphalia, Germany: what can be learnt for future flood risk management?

During the severe flooding in July 2021 189 people lost their lives in Germany, which is the highest number of flood-related fatalities since 1962. 49 people died in the densely populated state of North Rhine-Westphalia (NRW), whose flood risk management has, however, often been regarded as pioneering in Germany. To further improve flood risk management in NRW, the causes and circumstances of all 49 flood-related deaths were analyzed. Based on official files a structured document analysis was performed and a new coding scheme was developed that relates accident locations and victims’ activities to accident dynamics and causes of death. Circumstances and causes of death differed significantly between in-/outdoor incidents, age groups, and areas with different event magnitudes. Elderly people (>60 years) were particularly at risk; they account for two thirds of the dead. Eight of the 25 people who died in a building were surprised by water entry into basements or ground-floor apartments. In addition, there are indications that nine of 24 people who died outdoors were surprised and caught by water on their way home or when trying to leave the flooded zone. It is assumed that a lack of warning played a role in these cases. In most of the remaining cases, hazards were underestimated pinpointing to insufficient awareness and weaknesses of crisis and risk communication. 14 people died in their basements while attempting to inspect equipment (e.g., pumps) or to inspect, minimize, or repair damage. Since property-level adaptation has been emphasized in flood risk communication, life-threatening situations during fast onset-flooding and the priority to be safe have to be emphasized in future communications. It has to be acknowledged that the official hazard maps indicated no risk from flooding at around half of the 49 accident locations illustrating the exceptional event magnitude. Still, warning levels and flood hazard maps should be better linked to identify hazard zones and to enable appropriate behavior including (self-)evacuation.

How does your viewing perspective matter for decision-making with flood risk maps?*

ABSTRACT The globally increasing frequency of flood events highlights the importance of effective flood risk communication. The influence of the viewing perspective of mapped flood events on human risk perception has not yet been a research focus of the geovisualization community. This empirical study aims to fill this gap by investigating how the viewing perspective of flood risk maps, that is, 2D orthographic vs. 2.5D oblique views, influence human flood risk perception and decision-making. Results on how viewing perspective might influence measured risk perception are in line with prior inconclusive research on the utility and usability of adding a third viewing dimension on static maps. Unlike prior research would have suggested, we find that the individual risk attitude of our participants had no direct influence on their risk ratings in the context of this study. With additional empirical evidence on how static 2D and oblique 2.5D hazard maps might influence the public’s risk perception and decision-making, we hope to further inform policy and decision makers on the critical importance of well-designed cartographic displays for effective and efficient hazard and risk communication. We also provide an open-source code repository for making reproducible experiments with our static maps.

Investigating optimal 2D hydrodynamic modeling of a recent flash flood in a steep Norwegian river using high-performance computing

Abstract Efficient flood risk assessment and communication are essential for responding to increasingly recurrent flash floods. However, access to high-end data center computing is limited for stakeholders. This study evaluates the accuracy-speed trade-off of a hydraulic model by (i) assessing the potential acceleration of high-performance computing in PCs versus server-CPUs and GPUs, (ii) examining computing time evaluation and prediction indicators, and (iii) identifying variables controlling the computing time and their impact on the 2D hydrodynamic models' accuracy using an actual flash flood event as a benchmark. GPU-computing is found to be 130× and 55× faster than standard and parallelized CPU-computing, respectively, saving up to 99.5% of the computing time. The model's number of elements had the most significant impact, with <150,000 cells showing the best accuracy-speed trade-off. Using a PC equipped with a GPU enables almost real-time hydrodynamic information, democratizing flood data and facilitating interactive flood risk analysis.

A Framework for Creating Virtual Reality Models for More Effective Coastal Flood Risk Communication

A Framework for Creating Virtual Reality Models for More Effective Coastal Flood Risk Communication

Integrating cellular automata model into 3D representation for enhancing flood risk communication

Integrating cellular automata model into 3D representation for enhancing flood risk communication

Developing and pilot-testing warning messages for risk communication in natural disasters

Early warning systems are an essential tool for managing flood emergencies. Alert and warning applications and mobile-phone messaging services have become increasingly widespread among major international emergency agencies as means of communicating risks to the population, and their effectiveness in reducing human and material damages during flood events is significant. Despite their crucial importance, one of the main challenges in the field of emergency communication is the lack of protocols for systematic and standardized production of warning messages. While emergency agencies produce messages on a diversity of topic areas, there are no protocols for structuring their content according to communication functions, exhaustive identification of the relevant areas of action, or classification of content according to different topics. With a view to this opportunity for improvement, the aim of this article is to propose a method for creating a catalog of warning messages enabling their systematic composition and organization. To exemplify the successive stages in the development of such a catalog, we present here the resources and methodological process followed by the authors of this article when commissioned with this task by the emergency services of the Valencian Autonomous Region (south-east Spain) for flood-risk communication. The warning message catalog was pilot tested with experts and user focus groups. Developing warning message catalogs offers a vital resource that can enhance the outreach and operability of warning systems in the current context of increased flood risk due to climate change.