Risk assessments and disaster management are generally approached from a single-hazard perspective, ignoring the spatial and temporal connections and feedback loops that are involved when consecutive disasters occur. Not only can the total impact of a multi-hazard event differ from the sum of the impacts of the individual events, but the response and recovery process can also be more challenging for multi-hazard events when compared to a single-hazard disaster. Depletion of financial and human resources after a first hazard may for instance increase people’s vulnerability at the time of a second event. This was demonstrated in northern Mozambique, where tropical cyclones Idai and Kenneth made landfall only six weeks apart, early 2019. Despite continued high needs and dependence on humanitarian aid after the second event, UN agencies and partners struggled to provide additional support, due to exhausted stocks and funds after their initial response efforts to Idai. 

This study (that is part of the MYRIAD-EU project), focuses on post-disaster recovery, which is an often overlooked and misunderstood component of the disaster management cycle. A single-hazard approach to understanding recovery does not sufficiently reflect the complexity that is involved in multi-hazard events due to the potential feedbacks and interactions between hazards and their effects. While several recent studies have made efforts to improve our understanding of the relationships between single natural hazards and the recovery thereafter, recovery dynamics after multi-hazard events are still poorly understood. Additionally, the studies that have looked into recovery after natural disasters are often focussed on a single hazard type or limited set of extreme events in a specific region. To address this knowledge gap, this study sets out to compare economic recovery after multi-hazard events and single-hazard events on a continental scale.

Visible Infrared Imaging Radiometer Suite Nighttime Light (VIIRS NTL) data (2013-2022) are used as a proxy for economic recovery. To characterize recovery after different single- and consecutive events, accounting for geological, meteorological, and hydrological hazards, monthly changes in night light intensity are computed. A comparison of the recovery profiles of single- and multi-hazard events will then result in an improved understanding of the different trends and dynamics that are involved with economic recovery after multi-hazard events. The results of this study can be used by policy-makers and aid organizations to improve their disaster management strategies. Moreover, the resulting characterisation of economic recovery after single- and multi-hazard events will support future research into the identification of socio-economic factors that affect the recovery in a multi-hazard context.

How to cite: Buijs, S. L., de Ruiter, M. C., and Ward, P. J.: A continental-scale multi-hazard analysis of economic recovery using nighttime light satellite data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-717, https://doi.org/10.5194/egusphere-egu23-717, 2023.

Extensive disturbances during the mining and rehabilitation process can include removal of vegetation, removal and storage of soils hence their modification, changes in topography, and planting of new vegetation. A main goal of mine rehabilitation is to produce a post-mining landscape that is resistant to geotechnical failure and to surface erosion processes. To achieve this, hydrology and erosion models are required to determine erosion rates under alternative landscape designs, including landscape form and cover options.

By critical review of the relevant literature, it was found that most previous erosion modelling studies have concentrated on surface hydrology in agricultural, forestry, and other natural systems, while disturbed ecosystems like mining regions have received little attention. Landscape evolution models have been developed for mined landform applications but modelling over long time-scales compromises the temporal and spatial resolution.

The main objectives of this research therefore were:

• Extend an existing plot-scale hydrological model to plot-scale erosion model.
• To improve knowledge of the errors and uncertainty in applying a high-resolution erosion model to mined landforms and to conclude on the potential applicability and limitations of EroCA.

The experimental data used in the research were from a 30 m × 30 m field plot on a mine waste rock dump in the wet tropical environment of the Ranger mine (north-east Australia) from the period 2009 to 2014. The new EroCA model is an extension to the RunCA model, which was developed to provide high resolution simulation of runoff and infiltration in constructed landforms. The extended model uses mass balance principles and established erosion and sediment transport models, covering both suspended and bedload, and solves the equations using the cellular automata approach. Code verification against analytical solutions of runoff and sediment illustrated small errors, which were partly due to approximations used in the analytical solutions. The EroCA model was then applied to the Ranger experimental plot data to assess the suspended and bedload erosion performance. EroCA was able to reasonably represent the observed flows and turbidity profiles. Although an arbitrary reduction in the erodibility parameter value of 20% per year was needed to simulate the bedload depletion.

How to cite: Yavari, S., McIntyre, N., Shao, Q., and Baumgartl, T.: EroCA: a new tool for simulating constructed landform erosion, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2155, https://doi.org/10.5194/egusphere-egu23-2155, 2023.

Building multiple, complex risk scenarios is a priority for the improvement of the effectiveness of early warning systems and technical countermeasure designs to detect phenomena associated with severe weather events, such as floods and landslides.

This study introduces CERCA (Cascading Effects in Risk Consequences Assessment), a methodology for the characterisation of event scenarios that is consistent with the current Italian Civil Protection Guidelines on the national warning system for weather-related geo-hydrological and hydraulic risks.

The aim is to propose a simple, effective, multiscale operational tool that can be adapted to multiple purposes. Specifically, the methodology frames the problem as a typical scenario analysis through the assessment of possible cascading effects and consequences characterised by a cause/effect relationship produced by a triggering event. The proposed conceptual framework for ‘cascade scenario’ assessment consists of four stages, referring to the characterization of:

• Triggering Events,
• cascading effects in terms of Representative Elementary Phenomena,
• cascading effects in terms of Damaged Elements at Risk,
• Fatalities Circumstances.

The CERCA approach can be effective:

• in processing post-disaster information at the local level to identify site-specific dependencies based on local hazard proneness and exposure and vulnerability conditions as well as to prioritize countermeasures;
• in supporting efficient surveillance of the real-time evolution of critical situations, helping operative structures of civil protection to update the picture of occurring phenomena;
• in providing general dependency matrices to be used in the ‘ex-ante’ definition of scenarios and recurring cascading event trees, through analysis of several past events.

The methodology was assessed using a case study concerning a local event occurred in 2015 in the north-east of Calabria (Italy) and a back-analysis on 152 events in warning zones of the Italian territory that occurred during the period 2004–2021.

The first application aimed at illustrating CERCA functionality in describing cascading effects based on a post-disaster survey at a local level for a heavy rainfall event that caused flooding of various streams and widespread shallow landslides.

The national-scale back-analysis offered an overview of the chains generated by triggering events. The analysis showed that in over 50% of investigated cases, more than one triggering event was observed (most of the time floods accompanied by landslides), confirming the necessity for multi-risk analysis. ‘Pluvial flood’, particularly affecting urban areas, was the most frequent triggering event with 30%, mainly causing damage to basement or ground floor/yards of public and private buildings and to transport infrastructure. A detailed characterisation of the circumstances of death for 52 fatalities, further specified that the majority were flood-related fatalities (82%). Numerous people were affected outdoors along roads (35%) and travelling in vehicles (37%). Dependency matrices based on a frequency analysis, provided an overall picture of relations between different elements of the chain that, although limited to the number and type of investigated events, offers a preliminary assessment for further studies that could explore also the dependency from the severity of the forcing rainfall.

How to cite: Biondi, D., Scarcella, G. E., and Versace, P.: An operational tool for geo-hydrological scenario risk assessment and cascading effects evaluation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2413, https://doi.org/10.5194/egusphere-egu23-2413, 2023.

Multi-hazard risk perception represents a research subject that has been gaining momentum in the context of the Covid-19 pandemic, based on the interaction between management practices aiming to reduce infection rates and to reduce the impact of other co-occurring natural hazards. The concurrent hazards proved to be the source of many hurtful, high-cost, but still invaluable lessons that should be capitalised on by the new generations to progress towards improved multi-hazard management strategies, and to a more sustainable, resilient and equitable society, as proposed by the 2030 Agenda for Sustainable Development. However, such high-level orders cannot be obtained without an adequate understanding of the new challenges posed by multi-hazard risks.

This paper aims to investigate the multi-hazard risk perception of young professionals or students who follow education programmes that aim to develop knowledge and skills related to the very subject of perception (i.e., natural hazards and risks). Zooming in, the paper focuses on the specialization and study level-dependent differences concerning multi-hazard risk perception and hazard-related education insights of future potential specialists in natural hazard-induced risk management and tourism reconstruction. The most prominent research questions (What is the perception of the students and graduates regarding the extent to which the Covid-19 pandemic has amplified the impact of other risks ?, Are there differences in the perception of Geography/ Tourism students and graduates about the impact of different natural hazards on social and economic activities?), as well as secondary aspects of the inquiry were addressed by applying a multi-level questionnaire on 547 students and graduates of Geography and Tourism specializations from two universities in Iași City (Romania) and Novi Sad (Serbia).

The implementation of the t-test pointed out that the main specialization-dependent differences concerned the perception level of certain natural hazards at different sales, the estimation of the impact of different hazards on socio-economic activities (including tourism), and the estimation of the positive effects of hazard-related education. These differences are complemented by the ones that depend on the level of study, which were analyzed through ANOVA and referred the scale of the impact specific to biophysical hazards, the amplification effect of the pandemic on different hazard and vulnerability types, and the different education cycles that the Curriculum upgrade should be performed at. It should be noted that no statistically significant differences emerged between Geography and Tourism students and graduates regarding the impact of the Covid-19 pandemic on training / career. On the other hand, Bachelor and Master level participants reported to be more affected by the pandemic than respondents from the highest tire of university education.

This study represents the first of its type, as it offers valuable insights on the multi-hazard risk perception of students and graduates that may acquire future decision-making, hazard-related research or teaching jobs. Understanding the opinions formed in their training years or in early-career stages provides important cues about tomorrow’s hazard management, and tourism reconstruction practices.

How to cite: Margarint, M. C., Kovačić, S., Albulescu, A.-C., and Miljković, Đ.: The multi-hazard risk perception of young professionals and students in Geography and Tourism amid the Covid-19 pandemic, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2514, https://doi.org/10.5194/egusphere-egu23-2514, 2023.

Urban areas, the core of socio-economic activity with high population density, are considered highly vulnerable to flood hazards. Istanbul, Turkey's most populated city with around 16 million inhabitants, and at the same time commercial, cultural, and social capital, was chosen as the study area. Istanbul is a metropolis that has grown under unplanned growth, particularly with rural to urban migration in the 1950s. A significant portion of the city's natural areas, stream basins and valleys have been replaced by concrete surfaces. This transformation not only brought societal challenges, but increased urban vulnerability to extreme events and hazards. As a coastal city that consists of two peninsulas, Istanbul is highly prone to flash floods from heavy rainfalls. Flood events intensely impair the municipal services (e.g., public transportation, water and sanitation, electricity distribution), consequently affect the operation of businesses and public services, and cause high economic losses as well as even deaths and casualties. Many of the highly vulnerable zones for floods already endure inadequate housing and transport access. This study aims to build a flood vulnerability index to identify the districts vulnerable to floods in the metropolitan area and assess the impacts of floods on households and transportation infrastructure. The developed vulnerability index incorporates socioeconomic and physical vulnerability components, while also closely examining key transportation infrastructure in highly vulnerable locations. Using the multi-criteria decision making approach, 9 different indicators of flood vulnerability were evaluated, then weighted by stakeholders and experts using the Analytical Hierarchy Process (AHP) method. This methodology is implemented to 100 year flood zones and 500 year flood zones to represent the potential impact of future climate change. The proposed assessment disclosed that 22% of the basin has low urban flood vulnerability while the extremely vulnerable and vulnerable zones together constituted approximately 40% of the total area.  Approximately 75% of the road length (i.e., highways, main arteries, boulevards) and 20% of the public transportation lines (i.e., stations, railways, bus lines) across the basin are located in the vulnerable areas. The findings of the study have the potential to provide policymakers with up-to-date and detailed flood vulnerability assessments to serve as the foundation for their decision-making processes under flooding hazards.

How to cite: Daloglu Cetinkaya, I. and Pala, Ö. N.: Compound Vulnerabilities in an Urban Setting: Impact of Floods on the Transportation Network in Istanbul, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4825, https://doi.org/10.5194/egusphere-egu23-4825, 2023.

Assuming that greenhouse gas emissions continue to increase as the current trend, the global average temperature is expected to rise by about 5.7°C by the end of the 21st century. High temperatures and heat waves will increase across East Asia, including in Republic of Korea, and extreme weather events, such as heavy rains and floods, will intensify and become more frequent. Even if carbon neutrality is achieved, losses may still occur due to the limited ability of humans and natural systems to adapt to higher global average temperatures. According to CMIP6 (Coupled Model Intercomparison Project Phase 6), the global average temperature is projected to rise by 2℃ in 2036 (2022-2051, SSP126), by 3℃ in 2065 (2051-2080, SSP245), and it is forecasted to rise by 5.38℃ from 2070 to 2099 (SSP585). When the global average temperature rises by 1.5℃, Republic of Korea's average temperature rises by 0.34℃~0.75℃, a 2℃ increase by 0.82℃~1.01℃, and a 3℃ increase by 1.08℃~1.42℃. As global warming continues, it is analyzed that the difference between Korea and the global average temperature will become larger. Global warming in Republic of Korea is progressing faster than global warming, this will have serious repercussions in various sectors. It is necessary to comprehensively assess risks in various sectors and use the results to establish adaptation policy in order to prepare for damage caused by climate change in advance. This study provides information for comprehensive decision-making support by assessing and integrating climate change risks under the 2℃, 3℃, and end of the 21st century (Bau) scenario in health, energy, traffic, agriculture, forest, and water sectors. Key findings show the current (1985–2014) average annual number of days with heat wave warnings issued by the Korean Meteorological Administration is 6 days. This number is expected to increase to 29 days (+23 days) under 2℃ global warming and to 47 days (+41 days) under 3℃ global warming; it is expected to increase by a factor of 5-15 to 92 days (+85 days) by the end of the 21st century (BaU). The current average period of severe agricultural drought is 0.38 months per year. It will increase to 1.0 month (+0.64 months) under 2℃ global warming and to 0.8 months (+0.43 months) under 3℃ global warming; it is expected to increase to 1.6 months (+1.24 months) by the end of the 21st century (BaU), for a 1.1-4.3-fold increase. The results of the study is expected to contribute to the revitalization of global warming impact and risk assessment research by presenting the global warming period for each SSP scenario. It contributes to the establishment of scientific countermeasures linked to climate risks by predicting the risks of local governments due to global warming and analyzing the current status and characteristics of local governments' adaptation measures.

 [Acknowledgement] This paper is based on the findings of the environmental technology development project for the new climate regime conducted by the Korea Environment Institute (2022-070(R)) and funded by the Korea Environmental Industry & Technology Institute (2022003570004).

How to cite: Yu, I., Jung, H., Lee, D.-K., Lee, S.-H., and Hong, S.-I.: Multi-risk assessment due to global warming under the SSP climate scenario in the Republic of Korea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5301, https://doi.org/10.5194/egusphere-egu23-5301, 2023.

Mountain regions are subject to highly damaging hydrological and gravitational hazards. This exposure is due to their biophysical and societal characteristics. It is essential for a sustainable management of these risks to consider the natural risk as the result of complex interactions within the risk system, which is composed of a natural and a societal subsystem. In this way, it is possible to adopt a dynamic approach to the risk system by placing the phenomenon in an evolutionary context. We can therefore consider its trajectory according to the socio-environmental dynamics that influence it.

Studying these risk systems over the long term is necessary to understand their evolution and to anticipate future ones in order to guarantee the sustainability of mountain socio-ecosystems, and requires an interdisciplinary approach between geography and history.

The study of the trajectory of a multi-hazard system is being carried out in the Commune of Vallouise-Pelvoux, a high Alpine valley in the Écrins massif, France. This territory was chosen because it is subject to various risks that occur over a wide range of altitudes, its recent socio-economic development is mainly based on tourism, and it is marked by glacial recession, but also because we were aware of the availability of several sources allowing the production of event and multirisk chronologies.

The first stage of the research consisted in the production of a multi-hazard event chronology over 420 years (1600-2020). This database was built from various resources. On the one hand, from existing databases produced by public services and organizations such as the French Forest Office (ONF) specifically the mountain land restoration service (RTM) or the departmental councils. On the other hand, archival research was carried out in the municipal archives of Vallouise-Pelvoux and the departmental archives of the Hautes-Alpes.

After analysis of all available sources, the data collected was processed in various ways. Indeed, sources of different forms and origins requires standardization of the information to make it comparable and usable. The chronology was also subjected to a critical analysis : are the sources authentic? Reliable? What factors might influence them? 

Once this chronology of events in Vallouise-Pelvoux has been contextualized (changes in the natural and societal systems of the Commune), a first statistical analysis of the risks identified and the damage caused will be presented. In the future the data will be used to analyze the trajectory of the system.

How to cite: Dallons, L., Giacona, F., Eckert, N., and Frey, P.: Multi-hazard system of a high Alpine valley: construction of an event chronology from different sources, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6275, https://doi.org/10.5194/egusphere-egu23-6275, 2023.

As the effects of climate change intensify and energy supply issues become more prominent (ie: tackling the rise of CO2 emissions, conflict in Ukraine), the potential impacts of climate and energy variability on anthropogenic systems and question the ability of organisations to maintain their vital services and supply chains in the future.

However, there are many uncertainties surrounding climate change and the energy transition. As risk management is directly dependent on environmental conditions and energy supplies, it is necessary for risk managers to understand how these intertwined phenomena may alter current risk management strategies.

Although climate change is discussed and highlighted amongst the Disaster Risk Reduction community, the issue around the functioning of the energy system is not yet widely discussed and integrated into risk reduction strategies. This research focuses on assessing the perception of risk managers on environmental and energy risks in order to help them integrate climate change and the energy transition into risk management strategies. Our objective is to paint a picture of the global energy system and to integrate its future developments and limitations in order to prepare risk managers for the systemic changes of the 21st century.

How to cite: Mille, J., Charlton, D., De Ruiter, M., Haklay, M., and Edwards, S.: Training risk managers in the climate change and energy transition narrative to avoid maladaptation to the emerging 21st century paradigm., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7106, https://doi.org/10.5194/egusphere-egu23-7106, 2023.

The SIGALE (System of Information Geographic for grAvitational hazard vigiLancE assessment) project aims at developing an experimental early-warning system of gravitational hazard (landslides and rockfalls) over the road infrastructure network of Savoie (France). This network is about 3 300 km long.

We propose a new approach based on machine learning to predict a vigilance  degree. The vigilance degree is a combination of susceptibility model and trigger model.

The landslide susceptibility model is based on topographical data, landcover and lithology. The rockfall susceptibility model is based on statistical results of propagation using Flow-R.

The trigger models have been trained on an event database of 863 landslides and 481 rockfalls events from 2008 to 2020. The database covers 13 years, so about 4 745 days, over about 6 000 sectors. The thousand events are spread over 28 millions of spatio-temporal sectors. The dataset is thus highly unbalanced and specific machine learning has been deployed. The trigger models features are based on rainfalls and temperatures.

Our results show that, in spite of the high class imbalance issues of such database, the trigger models provide recall values of about 75%, with about 60% of precision.

Our prototype is a web-service showing vigilance degree model for both landslide and rockfall with different zooming information for decision support.

How to cite: Cadet, H., Rouquet, D., and Lescurier, A.: SIGALE: An online early warning system for gravitational hazard (Savoie, France), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7499, https://doi.org/10.5194/egusphere-egu23-7499, 2023.

Extreme weather events are among the most destructive natural hazards, affecting a large number of people and causing significant monetary damage globally each year. The impact of these events is increasing due to climate change and socio-economic development. While traditional approaches to risk assessment have focused on the impacts of single hazards, the combined risk of multiple hazards may be different from their sum. Their spatial and temporal co-occurrence may also be influenced by climate change. In this study, we develop a framework for modelling the combined risk of multiple climatic hazards, where risk is defined as the combination of hazard, exposure and vulnerability. We illustrate this method based on globally consistent river floods and tropical cyclones and their impacts on both population and assets. Both hazards are driven by global climate models to investigate their risk at current and future levels of warming. The combined impacts are evaluated by aggregating single hazard models on an event basis, where events are driven by the same climate model outputs. This allows us to not only consider the average annual impact, but also for example to assess combined extreme events or return periods. Additionally, spatially and temporally compounding events can be analysed. This framework is implemented in the open-source climate risk platform CLIMADA and can be applied to different climate risks, providing a more comprehensive approach to understanding and managing the risks posed by extreme weather events in a changing climate.

How to cite: Stalhandske, Z., Steinmann, C., Bresch, D. N., and Kropf, C.: Multi-hazard risk assessment of extreme weather events in a changing climate, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7782, https://doi.org/10.5194/egusphere-egu23-7782, 2023.

Understanding how individuals perceive risk of natural and health hazards can help policymakers, scientists, and clinicians to communicate risks. We show that individuals (as well as communities and institutions) cannot apply the precautionary principle to all threats, and thus we challenge the binary categorizations of risk takers vs. risk avoiders. To illustrate, we compared how people perceive the risk associated with natural and biological hazards in relation to the main preventable health-related risk factor – i.e. tobacco smoking by analyzing the results of nationwide surveys carried out in Italy and Sweden in August 2021. In particular, we compared smokers and non-smokers considering two domains of risk perception (likelihood and individual impact) for seven threats (epidemic, climate change, floods, droughts, wildfires, earthquakes and air pollution). Preliminary results show that: i) the risk perception of some threats is higher in smokers compared to non-smokers; and ii) this difference is mainly observed in a permissive tobacco environment. These results and their implications show the importance of integrating multi-risk components into risk communication, along with promoting policies that simultaneously address health and natural risks.

How to cite: Raffetti, E. and Di Baldassarre, G.: Can we be precautionary with respect to all risks? A natural and health hazards perspective, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11160, https://doi.org/10.5194/egusphere-egu23-11160, 2023.

Compound events have significant environmental and societal impacts and bring new challenges to decision-making, planning, and management. Meanwhile, knowledge about compound events and their impacts are limited. Sweden, while being prone to various climate-related natural hazards (e.g., storms, floods, wildfires) have no coherent information on where these events and their impacts have occurred in the past, and less so on compound events. Here we present a new cohesive natural hazards impact database for Sweden, including compound events, to advance our understanding of how these events have unfold during the last 50 years. The impact database consists of available data from multiple sources on past climate-related natural hazard events (e.g., databases and reports from governmental organizations, county boards, and scientific reports). These data have further been geocoded using a Geographic Information System (GIS) to generate an integrated natural hazards map. These two products will help provide knowledge on the spatiotemporal distribution of natural hazard events, including compound events in Sweden, and further advance our understanding of their underlying drivers, and aid ongoing work to effectively plan and prepare for these events.

How to cite: Mård, J., Bodin, Ö., and Nohrstedt, D.: Mapping and characterisation of compound events in Sweden, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14233, https://doi.org/10.5194/egusphere-egu23-14233, 2023.

The expansion of informal and uncontrolled urban landscapes commonly overlooks the natural constraints from the environment. This is particularly true for urban environments affected by landslides. Landslide risk assessment relevant for urban planning and disaster risk reduction (DRR) strategy requires highly spatially-resolved datasets and approaches. It also requires that both physical and social local aspects of risk are studied in an interdisciplinary manner. Such assessment of hazard risk remains challenging and under-researched in many regions, especially in low- and lower-middle-income countries in the tropics, as it usually requires large and diverse datasets that are frequently unavailable or unreliable. In addition, specifically in urban contexts, human-induced environmental change impacts slope stability. Under these conditions of data-scarcity and land transformation, reliable and detailed landslide risk assessment encompassing the physical and societal aspects in an operational approach strongly relies on expert knowledge.

In this research, we assess the risks associated with landslides in Bukavu, a city located in the eastern DR Congo where urban sprawling is high and the problem of landsliding is particularly acute. Firstly, we compiled a comprehensive multi-temporal landslide inventory covering several decades using remote sensing, archives, field survey and interviews with key informants. From this inventory, we derived three hazard zonations with multiple scenarios that allow to consider the interactions between various landslide processes and the role of human activities. Secondly, we obtained detailed socio-economic data from a sample population survey in morphological areas determined by remote sensing. Within two months, 10 specifically-trained local interviewers counted and located nearly 44,000 inhabitants living in about 6,580 households, and collected socio-economic baseline data over 10,880 people from 1,614 households. These demographic data were used to determine the variations in population density (exposure) in the city. These data were also key for the vulnerability assessment. For this, we designed a contextualised vulnerability index capturing the various dimensions of vulnerability with a set of selected indicators aimed at facilitating understanding, replicability and updating of the data collection. By combining hazard, exposure and vulnerability, we produced three risk zonation maps at a very high spatial resolution with the potential to be used operationally: one for shallow landslides, another for deformation within landslides and one for reactivation of deep-seated landslides. The development of these maps, as well as the collection of field-based information were carried out in close interaction with the city authorities and various stakeholders (e.g. civil protection, local community leaders) involved in DRR. A specific effort of awareness raising was also made through the organisation of dedicated workshops and radio programmes, and the implementation of a disaster risk information centre in Bukavu.

How to cite: Dewitte, O., Michellier, C., Mugaruka Bibentyo, T., Kulimushi Matabaro, S., Kadekere, I., Nzolang, C., and Kervyn, F.: Operational assessment of landslide risks in the sprawling city of Bukavu (DR Congo), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14325, https://doi.org/10.5194/egusphere-egu23-14325, 2023.

Istanbul is located one of the most seismically active regions of the earth. For this reason the city has suffered damage due to earthquakes in its historical process. Three of them, occurring in 1509, 1766, 1894 respectively,    seriously affected Istanbul and caused great loses around the city during the Ottoman period. 1509 Earthquake caused extensive damage to many mosques, buildings and some part of the city walls in Istanbul. 1509 Earthquake caused extensive damage to many mosques, buildings and some part of the city walls in Istanbul. Another destructive earthquake occured in the east part of the Sea of Marmara in 1766. Not only many houses and public buildings collapsed but also The Ayvad Dam located north of the Istanbul were damaged in İstanbul because of the 1766 Earthquake. Third major earthquakes took place in the Gulf of Izmit in 1894 and had adverse impact on Istanbul. On Augsut 17, 1999 The Kocaeli Earthquake with a magnitude 7.6 was the not only devastating but also deadly earthquake for Istanbul in recent years. Despite the approximately 110 km epicenter distance, 3,073 buildings suffered extensive damage, 11,339 buildings had moderate damage and 454 people died and 1880 people injured in Istanbul. Damages in Istanbul especially Avcılar and Büyükçekmece during Kocaeli Earthquake in 1999 raised and improved the awareness on disaster risk management since then several scientific and institutional studies has been conducted for the potential earthquake of Istanbul. Istanbul Metropolitan Municipality (IMM) carried out two major geo-scientific studies called “microzonation studies” covering more than 700 km2 of Istanbul’s urbanized areas between 2006 and 2009.     And then IMM has just started new microzonation project in order to complete remainder urbanization area of Istanbul consists of districts of Büyükçekmece, Beylikdüzü, Çatalca, Esenyurt, Küçükçekmece, Beşiktaş, Şişli, Sarıyer covering approximately 257 km². Esenyurt is the most populated district of Istanbul and the other districts host many Istanbulites. This project supports substantial hazard knowledges after the evaluation of geological, geotechnical and geophysical measurements in order comprehend these districts risk against the potential Istanbul earthquake,.  In the end “Land Suitability Maps” are derived from the combination of inputs using multi-hazard approach. Microzonation results could be used in land development/use plans, hazard identification in urban transformation, determination of the routes and characteristics of various types of engineering structures for making city resilient.

How to cite: Kara, S., Duran, K., Yılmaz, D., Yapar, E. R., Karasu, M. E., and Ergün Konukcu, B.: Multihazard Analysis: Istanbul Microzonation Projects, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16226, https://doi.org/10.5194/egusphere-egu23-16226, 2023.

Cities are increasingly faced with the complexities, the uncertainties, local and global challenges. These problems make pressures on the life of cities and cause direct, indirect, tangible and intangible damages on physical structure, natural environment, social fabric, cultural heritage and economic situation of the cities. In order to make cities resilient against these pressures, it is substantial to improve skills to cope with these difficulties and strengthen coping capacity of urban elements. Istanbul is one of the oldest cities in the world. The city, hosted many civilizations with its 8500 year history, has dealt with the earthquakes, epidemics, floods, fires, water shortages, economic crises throughout its historical process. Istanbul with more than 16 million population is still trying to struggle against the challenges based on natural events and climate change, the consequences of irresponsible urbanization, socio-economic and cultural stresses and environmental problems. This study reveals Sustainable Resilence Strategy of Istanbul with Sustainable Development Goals against to current and evolving acute shocks and chronical stresses by taking lessons from the past, forecasting future challenges, risk reduction, supra disciplinary and interdisciplinary studies,  holistic approach, shared decision making with multiple criteria ,  competent planning, manageable systems, resource management, funding capability, alternative strategy formation capability, reserve capacity, ensuring coordination between systems, increasing adaptive, absorbing and transformation capacity, providing continuity, developing national and international cooperation.

How to cite: Ergün Konukcu, B., Kara, S., Yılmaz, D., and Duran, K.: Resilient Istanbul against the evolving challenges, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16521, https://doi.org/10.5194/egusphere-egu23-16521, 2023.

Globally climate change has increased exposure to multiple hazards. In Sweden, 10-year events of precipitation and streamflow have started to cluster around the summer months for most of the country. However, Sweden's south and west coasts are especially vulnerable to river flooding events caused by extreme sea surges during the winter. This national-level analysis needs to be combined with detailed local assessments to quantify the hazard properly, its potential impacts and cascading effects. In response to this need, we explore the impacts of multiple hydrometeorological (i.e., weather and water) events that happen simultaneously or close together in Halmstad. Furthermore, we investigate the effects of climate change on the intensity and frequency of these hazards by focusing on extreme – low likelihood but high impact – events. Due to its geographical location, Halmstad is particularly vulnerable to flooding risks. Wind and waves combine to make the city vulnerable to flooding and storm surges. That confluence triggers extreme local sea level rise, resulting in high sea levels in Halmstad compared to nearby coastal towns. These compound flooding events in Halmstad are expected to increase in future climate scenarios. We will simulate multiple scenarios of compound flooding events with a two-dimensional hydrodynamic model. The model's values used as boundary conditions will be based on computed joint return intervals for fluvial flooding and extreme sea surge. This study can not only be used to support local adaptation strategies but will also contribute to the body of knowledge on the issue of compound flooding events in a changing climate. Local-scale assessments like this one are necessary for a nuanced understanding of the possible impacts of multiple hazards on society. At the same time, societies' dependency on critical infrastructure and vital societal services is increasing due to growing system complexity and interconnectedness. Together, these shifts will likely increase societal vulnerability and impact adaptive capacity.

How to cite: Ashraf, F. B., Passos, M. V., and Barquet, K.: Modelling compound flooding events for multiple hazards mapping: an example from Sweden., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16828, https://doi.org/10.5194/egusphere-egu23-16828, 2023.

The future of replacing illicit crops with cocoa in the South-Pacific region of Colombia goes far beyond the economic viability of these plantations. The process of social and ecological restoration (SER) that this process implies is intrinsically linked to the role of local organisations and the support of international non-governmental organisations, which are introducing the main technical improvements conditional on the achievement of social improvements. Here we analyse the situation in the South-Pacific region of Colombia, a territory traditionally dominated by illicit crops, inhabited by vulnerable Afro-American communities, and where post-conflict agreements are having a special relevance due to the high level of violence. This paper analyses the determinants of differences in the selling price of cocoa, assuming that the decision to be able to sell cocoa dry and access international markets is directly related to the support received by farmers. To be able to obtain a sustainable production of quality dry cocoa, the main requirement for accessing international market prices, is conditioned by access to adequate infrastructures. And, without access to this higher quality production, the substitution of illicit crops does not seem viable, and with it the environmental sustainability and social cohesion of the territory. Therefore, we analyse the determinants of farmers' ability to sell dry cocoa: percentage of cocoa damaged by pests, the pressure of violence. To do so, we use spatial econometric models, as these have been found to be more appropriate than other types of models. And we show that increasing the participation of producers in community councils supported by international NGOs is fundamental to achieving a better cocoa price.

How to cite: Quiroga, S., Suárez, C., Hernanz, V., and Aguiño, J. E.: A spatial analysis of the relevance of community organizations as an insurance against the economic and environmental vulnerability of Colombian cacao producers., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16861, https://doi.org/10.5194/egusphere-egu23-16861, 2023.

The assessment of flood impact on a Water Supply System (WSS) requires a comprehensive approach including several scales of analysis and models and should be managed in the Water Safety Plans (WSP), as recommended in the EU Water Directive 2020/2184. Flooding can affect the quality of groundwater and surface water resources and can cause supply service interruption due to damaged infrastructures. A complete approach to address flood impact on WSS is required but is not yet available, while only specific aspects were investigated in details.

In this context, the MUHA project, funded by the European INTERREG V-B Adriatic-Ionian ADRION Programme 2014-2020, developed a comprehensive tool named WAter Safety Planning Procedures Decision Support System (WASPP–DSS). The tool is mainly addressed to small water utilities (WU) for supporting WSP development and is based on two main premises: 1) a correct approach for WSS risk analysis requires a multi-hazard perspective encompassing all the system components and different hazards; 2) other institutions in addition to WUs have to be involved in WSS risk analyses to harmonize monitoring and response procedures.

The tool was tested on six pilot areas of the ADRION region considering four hazards: drought, flooding, accidental pollution and damage to infrastructure due to earthquakes. In this work, the tool is demonstrated for flooding impact analysis in three pilot areas: the Ridracoli reservoir in Italy and two municipalities, Larissa in Greece and Zadar in Croatia. The WASPP–DSS, tested by eight WUs, was found a potentially valid support for small WUs that must start drafting the WSP in a comprehensive way and can provide a common shared scheme.

Improvements are desirable, as including a specific section to consider the issue of loss of water resources from reservoirs due to overflow.

How to cite: Bonaccorsi, B., Barbetta, S., Tsitsifli, S., Boljat, I., Argiris, P., Lukač Reberski, J., Massari, C., and Romano, E.: Assessment of flooding impact on water supply systems: a comprehensive approach based on DSS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2811, https://doi.org/10.5194/egusphere-egu23-2811, 2023.

Nowadays, most of the coal mines in Europe are already closed or are in a state of liquidation. However, the problem of abandoned coal mines and their influence on the environment remains central for the mining industry and coal regions in transition. After the end of the exploitation, many disturbances can occur. Mines operators, local authorities and decision makers are confronted with multi-hazard and risks related to mine closure. Land use planning and adequate site rehabilitation requires better tools to deal with the multiple hazards and constraints.

The objective of the study is to improve risk assessment by establishing a new methodology to assess the interaction between hazards related to old mines, and no longer treat them separately.

Mining hazards concern: ground movements, hydrological hazards, self-heating, soil and water pollution. One hazard can trigger another one. Different tools are presented such as a global matrix, a fault tree, etc. for identifying the hazards interaction. The hazard interaction matrix has been constructed, figure 1 shows in particular the interactions that the phenomena in the columns (source phenomenon) can have with the phenomena in the rows (target phenomenon). The matrix also provides information on the levels of interaction: no known case of interaction between phenomena (white colour), Low (yellow), Medium (green) and High (red). These assessments are based on feedback and in-depth discussion between experts. This approach is a first tool to help mining and development actors to understand these interactions and improve mitigation and management measures.

How to cite: Marwan, A. H.: Multi-hazard analysis of abandoned coal-mines, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13325, https://doi.org/10.5194/egusphere-egu23-13325, 2023.