NH9.2

Severe flooding in Western Germany, Belgium and the Netherlands in July 2021, particularly along the rivers Erft, Ahr and Meuse rivers has led to more than 240 causalities and an estimated damage of 29,2 billion EUR in Germany alone. The high human and economic costs of the event brought systemic problems in the flood risk management system to light and raised questions about the limits of disaster risk management and climate change adaptation. Using a forensic disaster analysis approach, the Post Event Review Capability (PERC), we systematically analyse the strengths and weaknesses of the flood risk management systems in the affected regions, the emergency response and recovery to draw lessons for future disaster risk management and climate change adaptation strategies. For that, PERC synthesizes existing information about the event from the hydro-meteorological characteristics of the physical impact and combines it with qualitative interviews with first responders, flood risk managers and other directly affected stakeholders. We will present key findings from the PERC study on the 2021 floods including the main drivers behind the high casualties and potential shortcomings in the emergency response and recovery as well as recommendations and opportunities for improvement.

How to cite: Rözer, V., Ulrich, J., Szönyi, M., Ianni, F., Laurien, F., Deubelli, T., MacClune, K., and Norton, R.: Forensic disaster analysis of the 2021 summer floods in Western Germany, Belgium and the Netherlands – Findings from the PERC study, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6022, https://doi.org/10.5194/egusphere-egu22-6022, 2022.

Amidst a period of complete lockdown due  to COVID-19, the severe cyclonic storm Amphan made landfall in the Indian Sundarbans on 20 May 2020. The occurrence of a cyclone during  the pandemic warranted investigation of interconnected risks and impacts in this climate hotspot and eco-critical region. Based on a desk study, field observations, key informant interviews and expert consultations, this research focussed on better understanding direct and cascading risks and the associated impacts from the concurrence of the two hazards occurring simultaneously. Our analysis reveals that although the region has not experienced a high number of COVID-cases between March and August 2020, the presence of underlying vulnerabilities exposed the population to cascading effects caused by the pandemic-induced lockdown along with the compounding effect of the Cyclone Amphan. In the Indian Sundarbans, COVID-19 acted as an exogenous shock, but its interplay with interconnected vulnerabilities resulted in the emergence of disruptions of a systemic nature. This was particularly the case in the economic domain, with cascading impacts observed across the welfare, education, and employment sectors.  Cyclone Amphan, led to additional cascading impacts on these sectors, and affected other sectors such as health and infrastructure as well as biodiversity. Interventions such as introduction of new social protection schemes and community participation in cyclone preparedness measures have helped the system from facing a total collapse. However, some interventions that were implemented to mitigate impacts of these two concurring hazards somewhat counteracted one another. For example, while stringent COVID-19 interventions stressed on safety norms (including social distancing and stay at home orders), the hazard response protocol for Cyclone Amphan directed communities to evacuate their homes and move to communal shelters which were being used as quarantine units for returning migrant workers till before the cyclone. This caused concerns among the evacuated population, thus undermining the efficacy of the response effort. This case study underpins the need for moving from hazard-by-hazard approaches of understanding and managing risks towards integrated approaches that consider interconnected vulnerabilities, risks and impacts based on a systems perspective. Further, it also provides lessons for risk management in a multi-hazard and multi-risk setting besides sharing recommendations for better risk management in the Indian Sundarbans.

How to cite: Banerjee, S., Shekhar, H., Cotti, D., Sparkes, E., Werners, S., and Hagenlocher, M.: Revisiting risk in a multi-hazard setting: the case of Cyclone Amphan occurring within the COVID-19 pandemic in the Indian Sundarbans, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13432, https://doi.org/10.5194/egusphere-egu22-13432, 2022.

River floods are a common and often devastating environmental hazard causing severe damages, loss of lives and livelihoods, notably for the most vulnerable. Understanding the root causes, drivers, patterns and dynamics of flood risks and associated uncertainties is important to inform adequate risk management. Yet, a lack of understanding the highly dynamic processes, interactions, uncertainties, and the inclusion of participatory methods and transdisciplinary approaches in risk assessments remains a limiting factor. In many flood-prone regions of the world, data scarcity poses another serious challenge for risk assessments. Addressing the above, we developed an impact chain via desk study and expert consultation to reveal key drivers of flood risk for agricultural livelihoods in the Lower Mono River Basin of Benin and their interlinkages – a region that is both highly prone to flooding and can be considered data-scarce. Particularly, the dynamic formation of vulnerability and its interplay with hazard and exposure components is highlighted.

Based on a simplified version of the impact chain which was validated in a participatory manner during a virtual expert workshop, an alpha-level Bayesian Network was created to further explore these interactions. The model was applied to an exemplary what-if scenario for the study area in Benin. Based on the above, this study critically evaluates the benefits and limitations of integrating the two methodological approaches to better understand and simulate risk dynamics in data scarce environments. The study finds that impact chains are a useful approach to conceptualize interactions of risk drivers. Particularly in combination with a Bayesian Network approach the method enables an improved understanding of how different risk drivers interact within the system and allows for dynamic assessments of what-if scenarios, for example, to inform resilience building strategies.

How to cite: Wetzel, M., Schudel, L., Almoradie, A., Komi, K., Adounkpe, J., Walz, Y., and Hagenlocher, M.: The use of impact chains and Bayesian Network Analysis to assess flood risk dynamics in the Lower Mono River Basin, Benin, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11251, https://doi.org/10.5194/egusphere-egu22-11251, 2022.

On average, more than 21 million forced human displacements were reported as result of weather-related events between 2008 and 2020 worldwide. This is a major concern due to the increment trend in intensity and frequency of weather hazards. Breaking down the figures, the impact is more severe in low-middle income countries, where most of the natural hazards take place and adaptation strategies are lacking. Implementing efficient and operational policy responses requires a quantitative analysis of the nexus between climate-induced displacement. So far the study of this phenomenon has been often limited to qualitative assessments or to correlation measures from regression linear models, not accounting for the inherent complexity of the problem. The multicausal nature of human mobility and data availability present significant research challenges. We apply two methodological approaches that use machine-learning to close these gaps, namely addressing both rapid-onset (e.g. floods) and slow-onset (e.g. droughts) disaster types. The former uses the Internal Displacement Monitoring Centre (IDMC) global database of displacements triggered by floods and storms at disaster level, socioeconomic (RWI Meta Data4Good, Global Human Modification Layer, Education Expenditure), and Earth-Observation variables: meteorological (CHIRPS, ERA5) and environmental (NASA ASTER SRTM DEM, MODIS NDVI vegetation index). Explainable AI techniques enable to open the black box of random forest models and were applied at the global scale: Shapley values are used to investigate the contributions of the main drivers thereby quantitatively addressing the climate-displacement nexus. Results are consistent with the hazard, exposure and vulnerability concept discussed in literature and findings reveal that socioeconomic factors greatly mediate displacement magnitudes. The slow-onset study is being explored at the local scale at district level, currently focused on the effects of droughts on displaced populations in Somalia using UNCHR PRMN displacement dataset, remote sensing variables (CHIRPS, MODIS LST), conflict (ACLED) and market prices time-series (FSNAU, WFP VAM Unit). Beyond correlations analysis, causation alongside time-lag effects for the drivers of drought-induced displacement are assessed using the PCMCI algorithm. Results in specific districts indicate that decreases in vegetation in conjunction with cattle price drops are driving drought displacement, revealing these factors are in need for targeted intervention. Albeit the same method applied to other districts in Somalia returns no causal link among considered variables, taking these findings into account, we are able to propose district-wise recommendations on how to improve the quality of the data: eg. field data collection guidelines, what other data input is required, and where sampling efforts should be directed. 

How to cite: Tárraga Habas, J. M., Ronco, M., Miranda, M. T., Sevillano Marco, E., Wang, Q., Piles, M., Muñoz, J., and Camps-Valls, G.: Inspecting the link between climate and human displacement with Explainable AI and Causal inference, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11200, https://doi.org/10.5194/egusphere-egu22-11200, 2022.

Every year, extreme events caused by climate-related hazards result in severe impacts globally. These impacts are expected to increase in the future due to both climate change and population growth in exposed locations. However, impacts are not only driven by exposure to extreme events, but also by the population’s vulnerability to these hazards, determined by individual characteristics such as age, gender, and income. Thus far, global-scale climate risk assessments account for social vulnerability to a limited degree. To address this gap, we produce spatially explicit global datasets of variables that can be used for characterizing social vulnerability. We further combine these data into a globally consistent and spatially explicit Social Vulnerability Index (SoVI), which will be made publicly available along with the input variables. To explore the value of the SoVI in characterizing social vulnerability, we validate it with the observed impacts (e.g., fatalities, damages) of past extreme events. To do so, we overlay the spatial vulnerability characteristics with recently published flood maps of observed flooding events across the globe, also testing how each vulnerability variable performs individually in explaining the observed impacts. Our analysis helps to develop a more in-depth understanding of the characteristics that drive social vulnerability globally, along with their spatial distribution. Therefore, our results can support decision-making in developing strategies that reduce social vulnerability to climate-related hazards, for instance related to spatial planning, socioeconomic development, and adaptation.

How to cite: Reimann, L., Koks, E., de Moel, H., and Aerts, J.: Characterizing social vulnerability for climate impact assessment at global scale, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-135, https://doi.org/10.5194/egusphere-egu22-135, 2022.

Denmark is one of the most vulnerable countries in Europe with respect to increasing risk of sea surges. A two hundred year paradigm of land reclamation close to the sea must therefore be revisited with the intent of retaining flexibility and avoiding lock-ins while recognizing the unintended consequences of new adaptation strategies. Potential solutions continue to face considerable structural, spatial, temporal and definitional challenges requiring collaboration between communities, local actors and scientists. In the “Cities and rising sea levels” project scientists from different research disciplines including (landscape) architecture, regional and local planning, and hydrology collaborate with local actors in order to tackle these challenges. The aim is to establish a common terminology and identify common scenarios, strategies, and indicators of successful and less successful urban developments in coastal areas over space and time.

One of the objectives in the project is to establish a coherent, spatially explicit framework for assessing strategies for sustainable urban development (SUD) of coastal communities to facilitate mediation and decision-making for stakeholders involved in adaptation and urban planning processes. As a starting point, our study identified a total of >2200 indicators across 50 references on SUD and respective additional >1600 indicators across 28 references on coastal adaptation. By means of systemic reviews and analyses, the study builds upon previous reviews on indicators and expands beyond by laying a clear focus on sustainable adaptation in coastal areas.

Extracted indicators sets of SUD and coastal adaptation are compared and similarities as well as differences are pointed out and analysed. Interestingly none of the identified indicators of SUD include a direct representation of climate risks or determinants of risk i.e. vulnerability and exposure, neither as conceptual variables driving risk, nor the assessment of adaptive capacity. At the same time, indicators of coastal adaptation disregard liveability and human wellbeing as crucial aspects of urban planning, in contrast to SUD indicators where they represent guiding principles. This illustrates a clear gap between adaptation practices and other professions involved in urban planning processes.

In order to uncover sustainable pathways to adapt, adaptation must be an integral part of sustainable development. The study aims at understanding differences in performance assessments and to suggest steps forward to better integrate SUD and coastal adaptation. Here, the study will proceed by operationalizing a combined and integrated indicator framework in the form of spatio-temporal assessments. The first results of these assessments will be presented and synergies and tradeoffs between a risk lens and SUD will be highlighted.

How to cite: Eggert, A., Arnbjerg-Nielsen, K., and Löwe, R.: Comparative Analysis of Indicators for Sustainable Urban Development and Coastal Adaptation - Uncovering Barriers and Potentials of Integrated Assessments, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6341, https://doi.org/10.5194/egusphere-egu22-6341, 2022.

Land use planning has been espoused as a key measure to decrease the risk of climate change-relatd disasters including landslides, however there is a dearth of research on how it affects the psychosocial wellbeing of affected people. This ethnographic study examines the risk management of the Svínafellsheiði fracture in south-east Iceland, where 60 to 100 million cubic metres of debris is predicted to fall onto the glacier below, and cause flooding from or a tsunami in the proglacial lake. A no-build zone was put in place between 2018 and 2020 to prevent a further increase in the number of people exposed to the hazard. Our results indicate that the no-build zone had both direct and indirect adverse effects on the psychosocial wellbeing of those affected. It caused frustration about a perceived inability to make changes to home and businesses, people feeling that their future was in limbo or on hold, and people questioning their future in the area. These direct psychosocial effects also had the knock-on effect of causing people to talk more about the risk, thereby undermining a key coping mechanism. 

How to cite: Matti, S., Ögmundardottír, H., Aðalgeirsdóttir, G., and Reichardt, U.: Psychosocial response to risk mitigation measures in Iceland, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6600, https://doi.org/10.5194/egusphere-egu22-6600, 2022.

Residents in Álftaver, south Iceland, are very familiar with the 1918 Katla volcanic eruption, which caused rapid and catastrophic glacial outburst flooding of the area. Descriptions of the 1918 events, passed down by older generations, have become an important part of the collective memory. Based on oral and written history, this paper provides a vivid account, including detailed maps, of what people experienced and felt during the 1918 Katla eruption. It also considers how these experiences influence current-day perceptions and the impact this may have on behavior in relation to emergency response strategies. Until now, much of this history has only been accessible in Icelandic text and through oral stories. The aim of this paper is to unlock these stories for an international audience in an effort to advance understanding of volcanic eruptions and their impacts and, inform future emergency planning. Importantly, these descriptions tell us about the nature of the glacial outburst flood, with a ‘pre-flood’ devoid of ice and travelling at a much faster rate than the ice-laden main flood. As a future eruption of Katla may impact Álftaver, emergency response plans for glacial outburst floods were developed, and in March 2006 preliminary plans were tested in a full-scale evacuation exercise involving residents and emergency response groups. But Álftaver residents questioned the plans and were reluctant to follow evacuation orders during the exercise, as they felt their knowledge and the experience of their relatives during the 1918 Katla eruption, had not been taken into consideration. Residents were concerned that flood hazards, as well as tephra and lightning, were not appropriately accounted for by officials. In response to residents’ concerns, officials developed an alternative evacuation plan (Plan B) that builds on some of the experience and knowledge of Álftaver residents. However, residents were not involved in the development of ‘Plan B’ and they are not aware of what it constitutes or when it is to be implemented. This paper argues that more needs to be done to promote inclusive dialogue and the co-production of knowledge to ensure emergency response strategies adequately reflect and accommodate local knowledge, perspectives and planned behavior.

How to cite: Gísladóttir, G., Bird, D., and Pagneux, E.: What can we learn from previous generations? Álftaver’s experience of the 1918 Katla eruption, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12884, https://doi.org/10.5194/egusphere-egu22-12884, 2022.

Resilience to natural hazards varies widely within and between populations. People living in the same area affected by the same hazard event will experience it differently depending on their specific vulnerabilities and capacities. The social inequalities which drive differential resilience vary based on the norms of a given context, but result in resources being harder for some people to reach and use than others.

These inequalities are often invisible in traditional data, and therefore the needs of the most vulnerable are not addressed in disaster risk reduction and management policy and practice. The impacts of disasters therefore reinforce and worsen existing inequalities as already vulnerable people are left further and further behind.

This presentation will focus on new learning about the relationship between gender and social vulnerabilities and resilience to natural hazard-related disasters in a range of contexts with three key aims:

• To share key learning about differential disaster resilience and requirements of early warning and disaster risk management implementation
• To explore key tools which have been piloted, tested, and developed to improve knowledge and understanding of resilience
• To discuss effective and practical ways to apply these tools going forward in research, policy, and practice.

The presentation will draw on experiences and findings from projects conducted in the Philippines, Bangladesh, Malawi, Nepal, and Dominica to research gender and social inclusion in relation to early warning systems, disaster preparedness and response, and disaster risk financing.

The session will examine the drivers of social inequalities and their impacts relating to risk knowledge, monitoring and warning, communication and dissemination, and response capability, sharing examples of the different needs, considerations, and priorities relating to early warning and disaster risk management within communities.

We’ll then explore approaches to data layering and our Missing Voices methodology as key tools to identify and understand factors, including intersectional factors, influencing social and economic resilience to natural hazards.

How to cite: Sneddon, A., Budimir, M., Brown, S., and Nelder, I.: Gender and social inclusion in disaster risk reduction and management: Key learning and effective practices, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5537, https://doi.org/10.5194/egusphere-egu22-5537, 2022.

The effects of flooding on urban environment and social vulnerability are challenging issues in flood risk management and long-term planning. Flood risk is among the main causes of social crisis, as it can drastically affect the socioeconomic status of a community and an increase in flood events can significantly inhibit the political system of land and emergency management, social security, human welfare, and the economy.

In recent decades, several studies have illustrated how the probability of occurrence of a flood event can be modified by human-dependent factors, such as, among others, climate and land-use changes. 

For this reason, flood risk management policies are evolving to redirect the actions of policymakers from purely physical defensive measures toward integrated management and planning strategies, placing greater emphasis on the complexity of the interaction between social and physical processes.

The complexity of physical processes lies in the wide variety of underlying phenomena that produce different types of flooding, while that of social processes can be reconducted to their characterization, given by human-related factors such as risk perception, emotions, bonds, context, and behaviors. Structuring the complexity of these two systems could support flood risk to define the elements/classes of citizens that make a social system vulnerable.

Based on these premises, the present work aims in modelling the relationship between flood risk and community, starting from an analysis of social perception and knowledge of protective measures, and exploiting a methodology based on an online survey used to collect data, and on Mann-Whitney and Kruskal-Wallis tests used for their analysis.

The methodology was experimentally applied to the city of Brindisi (Puglia region, Southern Italy), which is potentially subject to floods of different nature, as fluvial, coastal and pluvial floods and dam overflows.

The results suggest that perceptions of flood risk depend on intrinsic components of individuals, primarily related to dimensions of perception such as trust in public strategies and risk communication. Slightly higher perception emerged for those living in risk areas, but the results of the remainder show that there is a non-negligible perception even where there is apparently no source of risk. This is reflected in the varying nature of the flooding that has affected the city. The presence of disabled persons in the household does not act in any way neither in the perception nor in the knowledge of the measures; the previous experience seems to have little weight in reference to the perception and almost null on the knowledge of the measures. This element is probably linked to the temporal distance from the last event that caused serious damage to the community. Knowledge of protective measures appears to be uniformly low for each category of citizens and territorial area, in particular for adolescents, a recurring category also on other investigated dimensions.

This work represents the first step for the development of a multi-agent model, as developed by the science of intelligent systems, able to analyze more deeply the relationships between natural and social systems and to bring out elements to support flood risk management.

How to cite: Santoro, S., Totaro, V., Lovreglio, R., Camarda, D., Iacobellis, V., and Fratino, U.: Structuring citizens’ risk perception and knowledge of flooding events for planning purposes: The case study of Brindisi, Italy, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10272, https://doi.org/10.5194/egusphere-egu22-10272, 2022.

Hydrological extremes still cause severe damage worldwide. Understanding people’s perceptions of drought and flood risk, and their changes over time, can help researchers, practitioners, and policymakers assist communities at risk. In particular, identifying and highlighting gender differences in the perception of hydrological risk is fundamental to promote fair disaster risk reduction policies which take such differences into account. To this end, we collected national survey data three times over a year on risk perception, knowledge, and preparedness in regard to floods and droughts in Italy and Sweden. Preliminary results show that: i) the perceptions of drought and flood risk are heavily intertwined; and ii) women show a higher fluctuation in perception over time compared to men, especially when it comes to floods. These results and their implications show how important it is to integrate gender into the management of floods and drought and into risk communication, as well as to promote policies that simultaneously address flood and drought risk.

How to cite: Mondino, E., Raffetti, E., and Di Baldassarre, G.: Public perceptions of flood and drought risk: Gender differences in Italy and Sweden, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2691, https://doi.org/10.5194/egusphere-egu22-2691, 2022.