Artificial intelligence (in particular, machine learning) can be used to predict and respond to natural disasters. The ITU/WMO/UNEP Focus Group AI for Natural Disaster Management (FG-AI4NDM) is building a community of experts and stakeholders to identify best practices in the use of AI for data processing, improved modeling across spatiotemporal scales, and providing effective communication. This multidisciplinary FG-AI4NDM-session invites contributions addressing challenges and opportunities related to the use of AI for the detection, forecasting, and communication of natural hazards and disasters. In particular, it welcomes presentations highlighting innovative approaches to data collection (e.g., via sensor networks), data handling (e.g., via automating annotation), data storage and transmission (e.g., via edge- and cloud computing), novel modeling or explainability methods (e.g., integrating quantum computing methods), and outcomes of operational implementation.

Recent advances in the field of Artificial Intelligence, Machine Learning and Data Assimilation have been massively applied to model, anticipate, and predict the natural catastrophes, such as earthquakes, floods, landslides, volcanic eruptions, tsunamis, wildfires, glacier instabilities, in addition to multi-hazard and cascading effects due to climate change. However, the adopted algorithms require a solid inductive bias, provided by the physics of the phenomenon at stake (or at least the understanding of it). Furthermore, due to simplified assumptions, analytical models might encounter limits while modeling these natural catastrophes. Therefore, several hybrid strategies, utilizing the growing computational resources, are currently being developed, to achieve more flexibility and full synergy between numerical physics-based simulations, machine learning and data-driven approaches.
The hybrid modeling of natural hazards benefits from the interpretability of numerical simulations and from the extrapolation and generalization capabilities of advanced Machine Learning methods. This synergy leads to multi-fidelity predictive tools that leverage all the available knowledge on the phenomenon at stake. Moreover, to tackle lack of data and representation, observational databases can be integrated with the synthetic results for re-analysis and for training machine learning algorithms on never-before-seen disaster scenarios. This multidisciplinary session invites contributions addressing hybrid solutions to predict and to mitigate natural catastrophes. It also welcomes presentations on hybrid tools for vulnerability assessment.

Both society and industry are becoming increasingly aware of the physical risks and potential knock-on impacts posed by climate change. This awareness is leading to an increased demand for specific and actionable information about such risks across a wide range of sectors and domains. Awareness of and demand for data on climate-related impacts across multiple different hazards and across large geographical areas is also rising - in many nations this is driven by new and upcoming legislation requiring businesses or governments to understand and be prepared for any and all climate risk. Although researchers in climate and geosciences are best-informed to provide expertise, traditional research outputs such as publications and corresponding data are not necessarily useable by non-experts within these domains. In this session, we explore how focusing on the needs of non-expert users and decision makers changes the way in which research is carried out, disseminated, and scaled.

We welcome abstracts across all natural hazard types and climate impacts on a broad range of themes, including: how to work effectively with stakeholders and other users; how user-engagement and data-delivery requirements change the way
science goals are set and met; and how to scale climate risk research to provide information beyond localised case-studies.

High-impact climate and weather events typically result from the interaction of multiple hazards as well as vulnerability and exposure across various spatial and temporal scales. Such compound events often cause more severe socio-economic impacts than single-hazard events, rendering traditional univariate extreme event analyses and risk assessment techniques insufficient. It is therefore crucial to develop new methodologies that account for the possible interaction of multiple physical drivers when analysing high-impact events. Such an endeavour requires (i) a deeper understanding of the interplay of mechanisms causing compound events and (ii) an evaluation of the performance of climate/weather, statistical and impact models in representing compound events.

We invite papers studying all aspects of compound events, which might relate to (but are not limited to) the following topics:

Synthesis and Analysis: What are common features for different classes of compound events? Which variables need to be assessed jointly in order to address related impacts? How much is currently known about the dependence between these variables?
Stakeholders and science-user interface: Which events are most relevant for stakeholders? What are novel approaches to ensure continuous stakeholder engagement?
Impacts: What are the currently available sources of impact data? How can they be used to link observed impacts to climate and weather events?
Statistical approaches, model development and evaluation: What are possible novel statistical models that could be applied in the assessment of compound events?
Realistic model simulations of events: What are the physical mechanisms behind different types of compound events? What type of interactions result in the joint impact of the hazards that are involved in the event? How do these interactions influence risk assessment analyses?

On February 6, 2023, two powerful earthquakes of magnitude 7.8 and 7.7 rocked south-central Türkiye and northern Syria, strongly affecting the regions around Gaziantep, Kahramanmaraş, Malatya, and Hatay. The epicenter of the first mainshock (37.288 N, 37.043 E, 8.6 km depth, origin time 01:17 AM UTC) is located close to the East Anatolian Fault (EAF). The second large earthquake (38.089°N, 37.239°E, 7.0 km depth, origin time 10:24 AM UTC) occurred only 9 hrs later, about 90 km north of the first mainshock on the east-west trending Sürgü Fault, at a time when the local population had already begun to rescue survivors and their belongings. The aftershock sequences delineate fault lengths of ~360 km and ~180 km for the M 7.8 and M 7.7 ruptures, respectively, rendering these earthquakes among the longest continental strike-slip earthquakes ever recorded. A basin-wide tsunami alert was issued by the NEAMTWS Tsunami Service Providers, and a small tsunami was generated which was measured in the Eastern Mediterranean Sea.

This session solicits contributions from all disciplines of Earth sciences, engineering, social sciences, disaster management, and policy making to glean a first-order interdisciplinary understanding of the causes and consequences of this devastating double earthquake event. We invite presentations that address the tectonic context of the EAF and large historical earthquakes in the region, measurements and inferences from earthquake geology and space imagery, studies on the coseismic rupture process of the two events and their physical connection, assessment of ground-shaking levels and strong-motion properties, site effects, damage and risk assessment, as well as tsunami forecasting and warning, and the societal implications of these devastating earthquakes.

Notes:
1. The Abstract Processing Charge (APC) for Turkish/Syrian scientists will be waived.
2. A regular APC rate of 50EUR will apply for all other scientists who are to submit an abstract for this late-breaking session.
3. The deadline for submitting an abstract to this session is 19.02.2023.
4. Please contact Philippe Jousset, sm@egu.eu, if it happens you already have submitted an abstract and yet want to submit an additional abstract to this session.

Heat extremes are already one of the deadliest meteorological events and they are projected to increase in intensity and frequency due to rising CO2 emissions. Also vulnerability and exposure of the events are likely to change, yet have to be assessed at a very local scale. The resulting risks of extreme heat events to society may increase dramatically with large regional differences, and society will need to adapt locally if the worst impacts are to be avoided. This session therefore welcomes a broad range of new research addressing the challenge of extreme heat and its impacts. Suitable contributions may: (i) assess the drivers and underlying processes of extreme heat in observations and/or models; (ii) explore the diverse socio-economic impacts of extreme heat events including vulnerability and exposure (for example, on aspects relating to human health or economic productivity); (iii) address forecasting and monitoring of extreme heat at seasonal to sub-seasonal time scales; (iv) focus on societal adaptation to extreme heat, including the implementation of Heat-Health Early Warning Systems for disaster risk reduction and (v) introduce transdisciplinary research frameworks for the assessment of societal relevant heat extremes and its impacts particularly in the Global South.

With global climate change affecting the frequency and severity of extreme meteorological and hydrological events, it is particularly necessary to develop models and methodologies for a better understanding and forecasting of present-day weather induced hazards. Future changes in the event characteristics as well as changes in vulnerability and exposure are among the further factors for determining risks for infrastructure and society, and for the development of suitable adaptation measures. This session considers extreme events that lead to disastrous hazards induced by severe weather and climate change. These can, e.g., be tropical or extratropical rain- and wind-storms, hail, tornadoes or lightning events, but also (toxic) floods, long-lasting periods of drought, periods of extremely high or of extremely low temperatures, etc. Papers are sought which contribute to the understanding of their occurrence (conditions and meteorological development), to assessment of their risk (economic losses, infrastructural damages, human fatalities, pollution), and their future changes, to the ability of models to reproduce them and methods to forecast them or produce early warnings, to proactive planning focusing on damage prevention and damage reduction. In order to understand fundamental processes, papers are also encouraged that look at complex extreme events produced by combinations or sequences of factors that are not extreme by themselves. The session serves as a forum for the interdisciplinary exchange of research approaches and results, involving meteorology, hydrology, environmental effects, hazard management and applications like insurance issues.

Flood is the foremost natural hazard around the world that affects human life and property (directly and indirectly). In the current era, many hydrologic and hydraulic modelling techniques are available for flood risk assessment and management, as well as for flood risk prevention and preparedness. Such techniques provide a platform for the scientific community to explore the causes of floods and to build up efficient methods for flood mitigation.
This session invites in-depth and applied research work carried out through flood modelling including hydrological modelling, flood hydrodynamic modelling, flood inundation mapping, flood hazard mapping, risk assessment, flood policy, and flood mitigation strategy. It also welcomes studies dealing with various uncertainties associated with different stages of modelling and exploring modern techniques for model calibration and validation. In addition, real-time flood inundation mapping is an important aspect for evacuating people from low-lying areas and reducing death tolls. Real-time data information through UAV-based flood inundation mapping and analysis of associated uncertainty in real-time aerial surveying are also welcome.

NB: please, see also the special issue recently released in NHESS linked with this session ( https://nhess.copernicus.org/articles/special_issue1218.html)

Floods are considered as one of the most devastating natural hazards globally and their impact is expected to increase as a result of climate change. Particularly, flooding in urban areas will result in greater impacts due to increased population residing in cities which is expected to be about 70% by 2050. There have been various enhancements in urban flood risk management in the last decade creating the opportunity to reduce risk to life and properties in cities. This special session is focused on these - advances in urban flood risk management, including but not limited to:
- improved representation of risk and its management (e.g. dynamic consideration of hazard and exposure);
- evacuation modelling and management;
- impact modelling to critical urban infrastructure, including cascading effects;
- new modelling techniques in flood risk management (such as application of emulators);
- new application and use of new data sources in flood modelling (such as remote sensing and real-time data, crowd-source data);
- application of nature-based solutions for urban stormwater management.

Lightning is the energetic manifestation of electrical breakdown in the atmosphere, occurring as a result of charge separation processes operating on micro and macro-scales, leading to strong electric fields within thunderstorms. Lightning is associated with tropical storms and severe weather, torrential rains and flash floods. It has significant effects on various atmospheric layers and drives the fair-weather electric field. It is a strong indicator of convective processes on regional and global scales, potentially associated with climate change. Thunderstorms and lightning are also associated with the production of energetic radiation up to tens of MeV on time scales from sub-millisecond (Terrestrial Gamma-ray Flashes) to tens of seconds (gamma-ray glows).

This session seeks contributions from research in atmospheric electricity with emphasis on:

Atmospheric electricity in fair weather and the global electrical circuit
Effects of dust and volcanic ash on atmospheric electricity
Thunderstorm dynamics and microphysics
Middle atmospheric Transient Luminous Events
Energetic radiation from thunderstorms and lightning
Experimental investigations of lightning discharge physics processes
Remote sensing of lightning and related phenomena by space-based sensors
Thunderstorms, flash floods, tropical storms and severe weather
Modeling of thunderstorms and lightning
Now-casting and forecasting of thunderstorms using machine learning and AI
Regional and global lightning detection networks
Lightning Safety and its Societal Effects

Hydrometeorological extremes are prevailing in most parts of the world, and their severity is rapidly increasing. Therefore, modeling practices to understand, predict and mitigate those extreme events are paramount. Among the many intervention measures, nature-based solutions such as restoring wetlands, applying green infrastructure in urban environments, and giving land back to nature (floodplains) are emerging. The application of nature-based solutions is a rapidly developing field of research in which many challenges and open questions are still central.
Hence, we would like to invite scholars (Professors, post-doctoral researchers, independent researchers, Ph.D. students, M.Sc. students, stakeholders, water companies, water managers, etc.) to take part in this nature-based solutions session during the EGU conference. We invite you all to submit your abstracts with the following main themes but in a broader context:
• Nature-based solutions for drought mitigation
• Nature-based solutions for flood mitigation
• Nature-based solutions integration in geohydrological modelling
• Frameworks to understand/evaluate effectiveness of nature-based solution applications
• Remote sensing to identify possible nature-based solution areas
• Nature-based solutions as climate change adaptation strategies
• Pilot projects and their implementation stage
• Effect of nature-based solutions on water quality and ecosystem services in general
• Ecosystem service quantification after the application of nature-based solutions
• Socio-economic value and community involvement for nature-based solution successfulness, etc.

Urban hydrological processes are characterized by high spatial variability and short response times resulting from a high degree of imperviousness. Therefore, urban catchments are especially sensitive to space-time variability of precipitation at small scales. High-resolution precipitation measurements in cities are crucial to properly describe and analyses urban hydrological responses. At the same time, urban landscapes pose specific challenges to obtaining representative precipitation and hydrological observations.

This session focuses on high-resolution precipitation and hydrological measurements in cities and on approaches to improve modeling of urban hydrological response, including:
- Novel techniques for high-resolution precipitation measurement in cities and for multi-sensor data merging to improve the representation of urban precipitation fields.
- Novel approaches to hydrological field measurements in cities, including data obtained from citizen observatories.
- Precipitation modeling for urban applications, including convective permitting models and stochastic rainfall generators.
- Novel approaches to modeling urban catchment properties and hydrological response, from physics-based, conceptual and data-driven models to stochastic and statistical conceptualization.
- Applications of measured precipitation fields to urban hydrological models to improve hydrological prediction at different time horizons to ultimately enable improved management of urban drainage systems (including catchment strategy development, flood forecasting and management, real-time control, and proactive protection strategies aimed at preventing flooding and pollution).
- Strategies to deal with upcoming challenges, including climate change and rapid urbanization.

Urban areas are at risk from multiple hazards, including urban flooding, droughts and water shortages, sea level rise, disease spread and issues with food security. Consequently, many urban areas are adapting their approach to hazard management and are applying Green Infrastructure (GI) solutions as part of wider integrated schemes.

This session aims to provide researchers with a platform to present and discuss the application, knowledge gaps and future research directions of urban GI and how sustainable green solutions can contribute towards an integrated and sustainable urban hazard management approach. We welcome original research contributions across a series of disciplines with a hydrological, climatic, soil sciences, ecological and geomorphological focus, and encourage the submission of abstracts which demonstrate the use of GI at a wide range of scales and geographical distributions. We invite contributions focusing on (but not restricted to):

· Monitored case studies of GI, Sustainable Drainage Systems (SuDS) or Nature Based Solutions (NBS), which provide an evidence base for integration within a wider hazard management system;

· GIS and hazard mapping analyses to determine benefits, shortcomings and best management practices of urban GI implementation;

· Laboratory-, field- or GIS-based studies which examine the effectiveness or cost/benefit ratio of GI solutions in relation to their wider ecosystem potential;

· Methods for enhancing, optimising and maximising GI system potential;

· Innovative and integrated approaches or systems for issues including (but not limited to): bioretention/stormwater management; pollution control; carbon capture and storage; slope stability; urban heat exchange, and; urban food supply;

· Catchment-based approaches or city-scale studies demonstrating the opportunities of GI at multiple spatial scales;

· Rethinking urban design and sustainable and resilient recovery following crisis onset;

· Engagement and science communication of GI systems to enhance community resilience.

Extreme hydro-meteorological events drive many hydrologic and geomorphic hazards, such as floods, landslides and debris flows, which pose a significant threat to modern societies on a global scale. The continuous increase of population and urban settlements in hazard-prone areas in combination with evidence of changes in extreme weather events lead to a continuous increase in the risk associated with weather-induced hazards. To improve resilience and to design more effective mitigation strategies, we need to better understand the triggers of these hazards and the related aspects of vulnerability, risk, and mitigation.
This session aims at gathering contributions dealing with various hydro-meteorological hazards that address the aspects of vulnerability analysis, risk estimation, impact assessment, mitigation policies and communication strategies. Specifically, we aim to collect contributions from academia, the industry (e.g. insurance) and government agencies (e.g. civil protection) that will help identify the latest developments and ways forward for increasing the resilience of communities at local, regional and national scales, and proposals for improving the interaction between different entities and sciences.
Contributions focusing on, but not limited to, novel developments and findings on the following topics are particularly encouraged:
- Physical and social vulnerability analysis and impact assessment of hydro-meteorological hazards
- Advances in the estimation of socioeconomic risk from hydro-meteorological hazards
- Characteristics of weather and precipitation patterns leading to high-impact events
- Relationship between weather and precipitation patterns and socio-economic impacts
- Hazard mitigation procedures
- Strategies for increasing public awareness, preparedness, and self-protective response
- Impact-based forecast, warning systems, and rapid damage assessment.
- Insurance and reinsurance applications
This session is linked to an active special issue in Natural Hazards and Earth System Sciences (NHESS): https://nhess.copernicus.org/articles/special_issue1203.html

Understanding and further predicting the incidence and severity of hydrometeorological hazards, such as floods, droughts, land slides and storm surges, are a key measure for risk mitigation, building resilience and supporting sustainable socio-economic development. This has become more important when our societies are facing climate change alongside the pressures induced by population growth, urbanisation and land use change. While traditionally physically based modelling approaches remain as a major tool base for studying the prognostics and diagnostics of these hazards, the ever high level of complexity of the underlying process and the interaction between the nature and human interface, and more importantly, the increasingly availability of new observations datasets, have necessitated many applications of tools and methods in the domain of hydroinformatics, such as data-driven modelling, machine learning, data fusion, alongside conventional sptial-temporal statistical analysis tools.

The aim of this session is to provide a platform and an opportunity to demonstrate and discuss innovative and recent advances of hydroinformatics applications and methodologies for analysing and producing diagnostics and prognostics of hydrometeorological hazards. It also aims to provide a forum for researchers from a variety of fields to effectively communicate their research. Submissions related to the following non-exhaustive topics are particularly welcome.
1. Spatial and temporal analysis of the incidence and distribution of hydrometeorological hazards;
2. Machine learning (e.g., CNN, GNN) in analysing and predicting hydrometeorological hazards.
3. Uncertainty quantification of coupled models, such as atmospheric-hydrological/hydrodynamic in the applications of diagnosing and predicting hydrometeorological hazards;
4. Development in quantitative methods for analysing compound hydrometeorological hazards;
5. Data assimilation and fusion of heterogeneous observations in hazards modelling, e.g., satellite-borne sensors and rainfall radars;
6. HPC (GPU) based algorithms and practice dealing with very large size datasets in prognostic modelling of hydrometeorological hazards, e.g., climate projections.
7. Modelling interface with human interactions in decision making, mitigation and impact studies.

Flash floods triggered by heavy precipitation in small- to medium-sized catchments often cause catastrophic damages, which are largely explained by the very short response times and high unit peak discharge. Often, they are also associated with geomorphic processes such as erosion, sediment transport, debris flows and shallow landslides. The anticipation of such events is crucial for efficient crisis management. However, their predictability is still affected by large uncertainties, due to the fast evolution of triggering rainfall events, the lack of appropriate observations, the changes due to a warming climate, the high variability and non-linearity in the physical processes, the high variability of societal exposure, and the complexity of societal vulnerability.
This session aims to illustrate current advances in monitoring, modeling, and short-range forecasting of flash floods and associated geomorphic processes, including their societal impacts.
Contributions related to recent and significant floods are particularly encouraged.
This session aims to specifically cover the following scientific themes:
- Monitoring and nowcasting of heavy precipitation events based on radar and remote-sensing systems (satellite, lightning, ..), to complement rain gauge networks
- Short-range (0-6h) heavy precipitation forecasting based on NWP models and/or ML-based approaches, with a focus on seamless forecasting strategies, and ensemble or probabilistic strategies for the representation of uncertainties.
- Understanding and modeling of flash floods, rainfall-induced hydro-geomorphic processes and their cascading effects, at appropriate space-time scales.
- Development of integrated hydro-meteorological forecasting chains and new modeling approaches for predicting flash floods and/or rainfall-induced geomorphic hazards in gauged and ungauged basins.
- New direct and indirect (proxy data) observation techniques and strategies for the observation or monitoring of hydrological reactions and geomorphic processes, and the validation of forecasting approaches.
- Development of impact-based modeling and forecasting approaches, including inundation mapping and/or specific impacts modeling approaches for the representation of societal vulnerability.

Hydro-meteorological extremes such as floods, droughts, storms, or heatwaves often affect large regions therefore causing large damages and costs. Hazard and risk assessments, aiming at reducing the negative consequences of such extreme events, are often performed with a focus on one location despite the spatially compounding nature of extreme events. While spatial extremes receive a lot of attention by the media, little is known about their driving factors and it remains challenging to assess their risk by modelling approaches. Key challenges in advancing our understanding of spatial extremes and in developing new modeling approaches include the definition of multivariate events, the quantification of spatial dependence, the dealing with large dimensions, the introduction of flexible dependence structures, the estimation occurrence probabilities, the identification of potential drivers for spatial dependence, and linking different spatial scales. This session invites contributions which help to better understand processes governing spatial extremes and/or propose new ways of describing and modeling spatially compounding events at different spatial scales.

Drought and water scarcity affect many regions of the Earth, including areas generally considered water rich. A prime example is the severe 2022 European drought, caused by a widespread and persistent lack of precipitation combined with a sequence of heatwaves from May onwards. The projected increase in the severity and frequency of droughts may lead to an increase of water scarcity, particularly in regions that are already water-stressed, and where overexploitation of available water resources can exacerbate the consequences droughts have. In the worst case, this can lead to long-term environmental and socio-economic impacts. Drought Monitoring and Forecasting are recognized as one of three pillars of effective drought management, and it is, therefore, necessary to improve both monitoring and sub-seasonal to seasonal forecasting for droughts and water availability, and to develop innovative indicators and methodologies that translate the data and information to underpin effective drought early warning and risk management.

This session addresses statistical, remote sensing and physically-based techniques, aimed at monitoring, modelling and forecasting hydro-meteorological variables relevant to drought and water scarcity. These include, but are not limited to: precipitation, snow cover, soil moisture, streamflow, groundwater levels, and extreme temperatures. The development and implementation of drought indicators meaningful to decision-making processes, and ways of presenting and integrating these with the needs and knowledges of water managers, policymakers and other stakeholders, are further issues that are addressed. Contributions focusing on the interrelationship and feedbacks between drought and water scarcity, hydrological impacts, and society are also welcomed. The session aims to bring together scientists, practitioners and stakeholders in the fields of hydrology and meteorology, as well as in the fields of water resources and drought risk management. Particularly welcome are applications and real-world case studies, both from regions that have long been exposed to significant water stress, as well as regions that are increasingly experiencing water shortages due to drought and where drought warning, supported by state-of-the-art monitoring and forecasting of water resources availability, is likely to become more important in the future.

The Sendai Framework for Disaster Risk Reduction (SFDRR) and its seventh global target recognizes that increased efforts are required to develop risk-informed and impact-based multi-hazard early warning systems. Despite significant advances in disaster forecasting and warning technology, it remains challenging to produce useful forecasts and warnings that are understood and used to trigger early actions. Overcoming these challenges requires understanding of the reliability of forecast tools and implementation barriers in combination with the development of new risk-informed processes. It also requires a commitment to create and share risk and impact data and to co-produce impact-based forecasting models and services. To deal with the problem of coming into action in response to imperfect forecasts, novel science-based concepts have recently emerged. As an example, Forecast-based Financing and Impact-based Multi-Hazard Early Warning Systems are currently being implemented operationally by both governmental and non-governmental organisations in several countries as a result of increasing international effort by several organizations such as the WMO, World Bank, IFRC and UNDRR to reduce disaster losses and ensuring reaching the objectives of SFDRR. This session aims to showcase lessons learnt and best practices on impact-based multi-hazards early warning system from the perspective of both the knowledge producers and users. It presents novel methods to translate forecast of various climate-related and geohazards into an impact-based forecast. The session addresses the role of humanitarian agencies, scientists and communities at risk in creating standard operating procedures for economically feasible actions and reflects on the influence of forecast uncertainty across different time scales in decision-making. Moreover, it provides an overview of state-of-the-art methods, such as using Artificial Intelligence, big data and space applications, and presents innovative ways of addressing the difficulties in implementing forecast-based actions. We invite submissions on the development and use of operational impact-based forecast systems for early action; developing cost-efficient portfolios of early actions for climate/geo-related impact preparedness such as cash-transfer for droughts, weather-based insurance for floods; assessments on the types and costs of possible forecast-based disaster risk management actions; practical applications of impact forecasts.

This session brings together scientists, forecasters, practitioners and stakeholders interested in exploring the use of ensemble hydro-meteorological forecast and data assimilation techniques in hydrological applications: e.g., flood control and warning, reservoir operation for hydropower and water supply, transportation, and agricultural management. It will address the understanding of sources of predictability and quantification and reduction of predictive uncertainty of hydrological extremes in deterministic and ensemble hydrological forecasting. Uncertainty estimation in operational forecasting systems is becoming a more common practice. However, a significant research challenge and central interest of this session is to understand the sources of predictability and development of approaches, methods and techniques to enhance predictability (e.g. accuracy, reliability etc.) and quantify and reduce predictive uncertainty in general. Ensemble data assimilation, NWP preprocessing, multi-model approaches or hydrological postprocessing can provide important ways of improving the quality (e.g. accuracy, reliability) and increasing the value (e.g. impact, usability) of deterministic and ensemble hydrological forecasts. The models involved with the methods for predictive uncertainty, data assimilation, post-processing and decision-making may include machine learning models, ANNs, catchment models, runoff routing models, groundwater models, coupled meteorological-hydrological models as well as combinations (multimodel) of these. Demonstrations of the sources of predictability and subsequent quantification and reduction in predictive uncertainty at different scales through improved representation of model process (physics, parameterization, numerical solution, data support and calibration) and error, forcing and initial state are of special interest to the session.

Karst environments are characterized by distinctive landforms and unique hydrological behaviors. Karst systems are extremely complex, heterogeneous and very difficult to manage, because their formation and evolution are controlled by a wide range of geological, hydrological, geochemical and biological processes, and are extremely variable in time and space. Furthermore, karst systems are highly vulnerable to a variety of hazards, due to the direct connection between the surface and subsurface through the complex networks of conduits and caves.
In karst, any interference is likely to have irreversible impacts and disturb the natural balance of the elements and processes. The great variability and unique connectivity may result in serious engineering problems: on one hand, karst groundwater resources are easily contaminated by pollution because of the rapidity of transmission through conduit flow, and remediation action, when possible, could be very expensive and require a long time; on the other hand, the presence of karst conduits that weakens the strength of the rock mass may lead to serious natural and human-induced hazards. The design and development of engineering projects in karst environments thus should necessarily require: 1) an enhanced understanding of the natural processes governing the initiation and evolution of karst systems through both field and modelling approaches, and 2) specific interdisciplinary approaches aimed at mitigating the detrimental effects of hazardous processes and environmental problems.
This session calls for abstracts on research from karst areas worldwide related to geomorphology, hydrogeology, engineering geology, hazard mitigation in karst environments in the context of climate change and increasing human disturbance.

Biogeomorphology addresses the two-way interaction between abiotic and biotic elements that shape landscapes at various spatio-temporal scales.

One key biogeomorphic interaction happens in fluvial ecosystems between wood, flow and sediment. Many river systems show disruptions in their natural wood regime and consequently deficits in habitat structures, biodiversity, and ecosystem functions. Large wood (LW) jams create upstream regions of slower, deepened water that may enable deposition and storage of nutrients. In addition, downstream regions of faster flow are created as flow diverges around LW jams and may increase transport of bedload sediment and aid flushing of fine particles from clogged gravels. During floods, the amount of transported LW may increase, jams can form at river infrastructure thus posing an additional flood risk. LW mobility is also important in the carbon cycle. Having highlighted the multiple active functions that LW may have on energy and matter fluxes, a cross-disciplinary effort is required to improve our understanding of the complex interactions of wood with flow and sediment in fluvial ecosystems.

Across all landscapes and ecosystems, investigation of biogeomorphic feedbacks remains poorly understood and quantitatively constrained. Improved understanding of abiotic-biotic interaction across scales improves the scientific basis for environmental management aiding climate change mitigation and adaptation, response to natural hazards, and design of nature-based solutions to increase system resilience.

This session combines the investigation of wood-flow-sediment interactions in fluvial ecosystems with a general biogeomorphic perspective on biotic-abiotic feedbacks across all landscapes and ecosystems. It aims for a broad representation of the scientific communities focusing on geomorphic, hydraulic, ecological, and human aspects associated with wood in rivers and biogeomorphology. We invite presenters to share recent scientific advances in our understanding and management of wood in fluvial ecosystems using field, laboratory, or numerical approaches. Likewise, we provide a platform for all aspects of biogeomorphology, including fundamental science and applied studies. This year we specifically invite contributions focusing on both the short (process-scale) and longer-terms (> centennial) relevance of biogeomorphology to the carbon cycle.

Worldwide, many areas are experiencing broad climatic and  environmental changes that lead to significant geomorphic impacts. These changes are manifested, for example, by changes in rainfall properties and in the frequency of extreme events. Especially naturally fragile arid to sub-humid areas are particularly sensitive to such changes. This makes them ideal areas to study such processes and their interactions for the recent and former periods, the latter being documented in different kinds of sediment archives. Recent technological advancements, and particularly a better understanding of the links between climate environmental changes and the surface dynamics, have made it possible to better recognize the impact of climatic and environmental triggers on geomorphic landscape processes during the last years.

This session will focus on contributions that discuss the  transformation of current and former climatic and environmental changes into geomorphic surface processes, from the scale of mountain ranges to watersheds and individual streams, as well as in aeolian, gravitational, and biological systems. We especially welcome studies that focus on geomorphic responses to changes in climate, extreme events and on their imprints on the landscape through erosion and sediment movement. We welcome studies from individual regions, different sediment archives and review studies. Modeling approaches that explicitly examine the effects of environmental changes on the landscape dynamics are highly encouraged, as well as studies dealing with novel methods to acquire chronological frameworks, process rates, and the impact of such processes on current and previous societies.

Sediment transport is a fundamental component of all geomorphic systems (including fluvial, aeolian, coastal, hillslopes and glacial), yet it is something that we still find surprisingly difficult both to monitor and to model. Robust data on where and how sediment transport occurs are needed to address outstanding research questions, including the spatial and temporal controls on critical shear stress, the influence of varying grain size distributions, and the impact of large magnitude events. Recent developments have provided a) new opportunities for measuring sediment transport in the field; and b) new ways to represent sediment transport in both physical laboratory models and in numerical models. These developments include (but are not limited to) the application of techniques such as seismic and acoustic monitoring, 3D imaging (e.g. CT and MRI scanning), deployment of sensors such as accelerometers, replication of field topography using 3D printing, use of luminescence as a sediment tracer, remote sensing of turbidity, discrete numerical modelling, and new statistical approaches.

In this session we welcome contributions from all areas of geomorphology that develop new methods for monitoring and modelling all types of sediment transport, or that showcase an application of such methods. Contributions from ECRs and underrepresented groups are particularly encouraged.

This session investigates mid-latitude to subtropical cyclones and storms on both hemispheres. We invite studies considering cyclones in different stages of their life cycles from the initial development, to large- and synoptic-scale conditions influencing their growth to a severe storm, up to their dissipation and related socioeconomic impacts. We also welcome studies investigating these weather systems and their climate controls in subtropical regions of both hemispheres.

Papers are welcome, which focus also on the diagnostic of observed past and recent trends, as well as on future storm development under changed climate conditions. This will include storm predictability studies on different scales. Finally, the session will also invite studies investigating impacts related to storms: Papers are welcome dealing with vulnerability, diagnostics of sensitive social and infrastructural categories and affected areas of risk for property damages. Which risk transfer mechanisms are currently used, depending on insured and economic losses? Which mechanisms (e.g. new reinsurance products) are already implemented or will be developed in order to adapt to future loss expectations?

Volcanic gas emissions can constitute a permanent hazard in volcanic areas not only during eruptions, but also in post-eruptive and quiescent periods. Carbon dioxide is one of the main hazardous volcanic gases due to its characteristics (odourless, invisible, density higher than air at STP) and asphyxiate effect. However, we highlight also the presence of other gases, such as hydrogen sulphide and radon. In fact, several incidents with gases have been reported both indoor and outdoor in various countries during non-eruptive periods: USA, Argentina, Italy, Portugal, Greece, Congo, and Indonesia, just to give some examples.
High CO2 concentrations have been recently detected in some villages in La Palma (Canary Islands) and Vulcano (Italy) posing a threat to population and restricting the access to dwellings. We aim at contributions that show strategies to monitor, prevent and manage these silent hazards, which are quite challenging. Development of new sensors and study cases are welcome.

The panel's objective is to examine the multiple dimensions associated with risk by adopting a perspective examining the reference regulatory framework and the organizational and procedural repercussions of a vision in which risk (its assessment) is assumed to be a necessary component of administrative decision-making.
The consideration of risk must find an appropriate place within the processes of defining the planning lines of the territories, following a line of continuity that from it passes through the decision to find the balance between the possibility of an event occurring and the costs related to the adoption of prevention and precautionary measures often relegate the consideration of risk to a secondary level.
The aim is to verify, with specific reference to volcanic risk, the different dimensions mentioned above, going in search of the degree of risk assessment at the regulatory, programmatic, and planning stage and the regulatory and procedural instruments aimed at guaranteeing the effectiveness of the dialogue between law and technique, a prerequisite for the correct application, and therefore the effectiveness, of the principles of precaution and prevention.
This relation will be examined in depth, highlighting, for example, the role that permanent monitoring and observation systems, possibly also in collaboration with the operational groups envisaged for seismic emergencies, can play in defining that framework of knowledge and procedures for the dissemination and transmission thereof, which is indispensable for proper territorial planning. A focus will be reserved for the data collected from the observations of the monitoring networks to verify the degree of penetration they have within public decision-making processes, including urban planning decisions and specific planning decisions for managing emergencies such as plans and red evacuation zones.
The analysis of the data, which includes the verification of the costs that failure to consider volcanological risk entails, is functional to the formulation of proposals for the identification of guidelines that define tools and methods through which to ensure stability and convergence between administration, prevention and technical knowledge from the volcanic risk perspective, drawing on recent experience to renew the vision of a truly resilient administration and response.

Monitoring of volcanic hazards by combining field observations, satellite data and numerical models, presents extraordinarily challenging problems, from detecting and quantifying hazardous phenomena during eruptive events to forecasting their impact to assess risks to people and property. This session welcomes contributions addressing unresolved challenging questions related to complex geophysical flow modeling, including physical-mathematical formulations, numerical methods and satellite data analysis as well as contributions that cross-fertilize efforts in traditional volcano monitoring with new technological innovations from statistical methods and artificial intelligence. Goals for the session include: (i) expanding knowledge of complex volcanic processes and their space-time dynamics; (ii) monitoring and modeling volcanic phenomena; (iii) evaluating model robustness through validation against real case studies, analytical solutions and laboratory experiments; (iv) quantifying the uncertainty propagation through both forward (sensitivity analyses) and inverse (optimization/calibration) modeling in all areas of volcanic hazard; (v) investigating the potential of machine learning techniques to process remote sensing data for developing a better understanding of volcanic hazards.

Volcanoes release gas effluents and aerosol particles into the atmosphere during eruptive episodes and by quiescent emissions. Volcanic degassing exerts a dominant role in forcing the timing and nature of volcanic unrest and eruptions. Understanding the exsolution processes of gas species dissolved in magma, and measuring their emissions is crucial to characterise eruptive mechanism and evaluate the sub-sequent impacts on the atmospheric composition, the environment and the biosphere. Emissions range from silent exhalation through soils to astonishing eruptive clouds that release gas and particles into the atmosphere, potentially exerting a strong impact on the Earth’s radiation budget and climate over a range of temporal and spatial scales. Strong explosive volcanic eruptions are a major natural driver of climate variability at interannual to multidecadal time scales. Quiescent passive degassing and smaller-magnitude eruptions on the other hand can impact on regional climate system. Through direct exposure and indirect effects, volcanic emissions may influence local-to-regional air quality and seriously affect the biosphere and environment. Volcanic gases can also present significant hazards to populations downwind of an eruption, in terms of human, animal and plant health, which subsequently can affect livelihoods and cause socio-economic challenges. Gas emissions are measured and monitored via a range of in-situ and remote sensing techniques, to gain insights into both the subterranean-surface processes and quantify the extent of their impacts. In addition, modelling of the subsurface and atmospheric/climatic processes, as well as laboratory experiments, are fundamental to the interpretation of field-based and satellite observations.

This session focuses on the state-of-the-art and interdisciplinary science concerning all aspects of volcanic degassing and impacts of relevance to the Volcanology, Environmental, Atmospheric and Climate sciences (including regional climate), and Hazard assessment. We invite contributions on all aspects of volcanic plumes science, their observation, modelling and impacts. We welcome contributions that address issues around the assessment of hazards and impacts from volcanic degassing both in crises and at persistently degassing volcanoes.

Over the past few years, major technological advances significantly increased both the spatial coverage and frequency bandwidth of multi-disciplinary observations at active volcanoes. Networks of instruments, both ground- and satellite-based, now allow for the quantitative measurement of geophysical responses, geological features and geochemical emissions, permitting an unprecedented, multi-parameter vision of the surface manifestations of mass transport beneath volcanoes. Furthermore, new models and processing techniques have led to innovative paradigms for inverting observational data to image the structures and interpret the dynamics of volcanoes. Within this context, this session aims to bring together a multidisciplinary audience to discuss the most recent innovations in volcano imaging and monitoring, and to present observations, methods and models that increase our understanding of volcanic processes.
We welcome contributions (1) related to methodological and instrumental advances in geophysical, geological and geochemical imaging of volcanoes, and (2) to explore new knowledge provided by these studies on the internal structure and physical processes of volcanic systems.
We invite contributors from all geophysical, geological and geochemical disciplines: seismology, electromagnetics, geoelectrics, gravimetry, magnetics, muon tomography, volatile measurements and analysis. The session will include in-situ monitoring and high- resolution remote sensing studies that resolve volcanic systems ranging from near-surface hydrothermal activity to deep magma migration.

The session deals with the documentation and modelling of the tectonic, deformation and geodetic features of any type of volcanic area, on Earth and in the Solar System. The focus is on advancing our understanding on any type of deformation of active and non-active volcanoes, on the associated behaviours, and the implications for hazards. We welcome contributions based on results from fieldwork, remote-sensing studies, geodetic and geophysical measurements, analytical, analogue and numerical simulations, and laboratory studies of volcanic rocks.
Studies may be focused at the regional scale, investigating the tectonic setting responsible for and controlling volcanic activity, both along divergent and convergent plate boundaries, as well in intraplate settings. At a more local scale, all types of surface deformation in volcanic areas are of interest, such as elastic inflation and deflation, or anelastic processes, including caldera and flank collapses. Deeper, sub-volcanic deformation studies, concerning the emplacement of intrusions, as sills, dikes and laccoliths, are most welcome.
We also particularly welcome geophysical data aimed at understanding magmatic processes during volcano unrest. These include geodetic studies obtained mainly through GPS and InSAR, as well as at their modelling to imagine sources.

The session includes, but is not restricted to, the following topics:
• volcanism and regional tectonics;
• formation of magma chambers, laccoliths, and other intrusions;
• dyke and sill propagation, emplacement, and arrest;
• earthquakes and eruptions;
• caldera collapse, resurgence, and unrest;
• flank collapse;
• volcano deformation monitoring;
• volcano deformation and hazard mitigation;
• volcano unrest;
• mechanical properties of rocks in volcanic areas.

Debris flows are among the most dangerous natural hazards that threaten people and infrastructures in both mountainous and volcanic areas. The study of the initiation and dynamics of debris flows, along with the characterization of the associated erosion/deposition processes, is of paramount importance for hazard assessment, land-use planning and design of mitigation measures, including early warning systems. In addition, the impacts of climate change on debris-flow activity must be considered and carefully analyzed, as the number of mountain areas prone to these events may increase in future.
A growing number of scientists with diverse backgrounds are studying debris flows and lahars. The difficulties in measuring parameters related to their initiation and propagation have progressively prompted research into a wide variety of laboratory experiments and monitoring studies. However, there is a need of improving the quality of instrumental observations that would provide knowledge for more accurate hazards maps and modeling. Nowadays, the combination of distributed sensor networks and remote sensing techniques represents a unique opportunity to gather direct observations of debris flows to better constrain their physical properties.
Scientists working in the field of debris flows are invited to present their recent advancements. In addition, contributions from practitioners and decision makers are also welcome. Topics of the session include: field studies and documentation, mechanics of debris-flow initiation and propagation, laboratory experiments, modeling, monitoring, impacts of climate change on debris-flow activity, hazard and risk assessment and mapping, early warning, and alarm systems.

Large mass movements in rock, debris and ice in glacial masses, represent enormous risks impacting on the socio economic tissue. These complex systems are difficult to describe, investigate, monitor and model. Hence a reliable model of these phenomena requires acquisition and analysis of all the available data. This is the key to support successive steps up to the management of Early Warning systems.
Large instabilities affect all the materials (rock, weak rocks, debris, ice), from low to high altitudes, evolving as slow or fast complex mass movements. This and the complex dependency on forcing factors result in different types and degrees of hazard and risk. Some aspects of these instabilities are still understudied and debated, because of the difficult characterization and few cases thoroughly studied. Regional and temporal distribution and relationships with controlling and triggering factors are poorly understood resulting in poor predictions of their behavior and evolution under present and future climate. Relationships among geological and hydrological boundary conditions and displacements are associated to mechanical controls, hydraulic response and evolution in space and time. Even for well studied and active phenomena warning thresholds are mostly qualitative, based on semi-empirical approaches and do not consider all available data. Then a multidisciplinary approach and a robust set of monitoring data are needed. Many modeling approaches can be applied to evaluate instability and failure, considering triggerings (e.g. rain, seismicity, eruption, snowmelt), failure propagation, leading to rapid mass movements (rock, debris, ice avalanches, flows). Nevertheless, the applied approaches are still phenomenological in most cases and have difficulty to explain the observed behavior. Impacts of such instabilities on structures represents a relevant risk but also an opportunity in terms of investigations and quantitative measurements of effects on structures (e.g. tunnels, dams, roads). Design of these structures and knowledge of their expected performance represent an important element.
We invite all the researchers to present case studies, sharing views and data, to discuss monitoring and modeling approaches and tools, to introduce new approaches for thresholds definition, including advanced numerical modeling, Machine Learning for streamline and offline data analyses, development of monitoring tools and dating or investigation techniques.

Across the world, a large part of slope instability phenomena is recognized to be regulated by weather patterns largely differing in terms of variables (precipitation, temperature, snow melting) and significant time span (from a few minutes up to several months). Furthermore, weather dynamics largely influence land use/cover playing a key role in the slope-atmosphere interaction. All the mentioned variables are subject to changes due to the observed and expected global warming and resulting climate change. Finally, in recent years, the design, implementation and maintenance of Nature Based Solutions as protection measures for landslide events, heavily connected with weather dynamics, gained a well-deserved interest.
The overall impacts of weather variables (and their changes) depend on the region, spatial scale, time frame, and socio-economic context addressed. However, although even the simple identification of the weather patterns regulating the occurrence of landslide activity represents a not trivial issue, also assuming steady conditions, the expected variations induced by unequivocal global warming make the issue highly complex and require further in-depth investigation.
To support hazards’ monitoring, predictions, and projections, last-generation and updated datasets with high spatio-temporal resolution and quality - as those from the Copernicus Services’ Portals - are useful to feed models, big-data analytics, and indicators’ frameworks enabling timely, robust, and efficient decision making.
The Session aims at presenting studies concerning the analysis of the role of climate-related variables and slope-atmosphere interaction on landslide triggering/activity and/or effectiveness of protection measures, across different geographical contexts and scales. Modelling and monitoring investigations to properly evaluate the energy and water fluxes at the interface and improve the current generation of predictive models are encouraged. Furthermore, are greatly welcome investigations focused on innovative approaches through which the variations induced by climate change on landslide triggering, dynamics, and hazard are analysed. Either studies including analyses of historical records and related climate variables, or modelling approaches driven by future climate exploiting downscaled output of climate projections fit the Session’s purposes. Studies assessing variations in severity, frequency, and/or timing of events and consequent risks are valuable.

Rockfalls, rockslides and rock avalanches are among the primary hazards and drivers of landscape evolution in steep terrain. The physics of rock slope degradation and dynamics of failure and transport mechanisms define the hazards and possible mitigation strategies and enable retrodictions and predictions of events and controls.

This session aims to bring together state-of-the-art methods for predicting, assessing, quantifying, and protecting against rock slope hazards across spatial and temporal scales. We seek innovative contributions from investigators dealing with all stages of rock slope hazards, from weathering and/or damage accumulation, through detachment, transport and deposition, and finally to the development of protection and mitigation measures. In particular, we seek studies presenting new theoretical, numerical or probabilistic modelling approaches, novel data sets derived from laboratory, in situ, or remote sensing applications, and state-of-the-art approaches to social, structural, or natural protection measures. We especially encourage contributions from geomechanics/rock physics, geodynamics, geomorphology and tectonics to better understand how rockfall, rockslides and rock avalanches act across scales.

Landslides are ubiquitous geomorphological processes that can have disastrous consequences. Landslides can cause more deaths than any other natural hazard in a number of countries. Predicting landslides is a challenging problem that is important for scientific interest and societal impact because it has the potential to safeguard lives, individual assets, and shared resources. The session's main focus is on cutting-edge approaches and strategies for predicting landslides, including the location, timing, magnitude, and destructiveness of single and multiple slope failures. All landslide types—from fast rockfalls to rapid debris flows, from slow slides to very rapid rock avalanches—are taken into account, from the local to the global scale. Contributions looking at theoretical aspects of predicting natural hazards, with a focus on landslide forecasting, are of interest. These include contributions examining conceptual, mathematical, physical, statistical, numerical, and computational problems, as well as applied contributions showing, with examples, whether it is possible or not to predict individual or multiple landslides, or specific landslide characteristics. Abstracts that evaluate the quality of landslide forecasts, compare the efficiency of various forecasting models, use landslide forecasts in operational systems, and investigate the potential for exploitation of new or emerging technologies, are welcome as well. We anticipate that, in case of a successful session, the most relevant contributions will be collected in the special issue of an international journal.

Landslide early warning systems (LEWS) are cost effective non-structural mitigation measures for landslide risk reduction. For this reason, the design, application and management of LEWS are gaining consensus not only in the scientific literature but also among public administrations and private companies.
LEWS can be applied at different spatial scales of analysis, reliable implementations and prototypal LEWS have been proposed and applied from slope to regional scales.
The structure of LEWS can be schematized as an interrelation of four main components: monitoring, modelling, warning, response. However, tools, instruments, methods employed in the components can vary considerably with the scale of analysis, as well as the characteristics and the aim of the warnings/alerts issued. For instance, at local scale instrumental devices are mostly used to monitor deformations and hydrogeological variables with the aim of setting alert thresholds for evacuation or interruption of services. At regional scale rainfall thresholds are widely used to prepare a timely response of civil protection and first responders. For such systems, hydro-meteorological thresholds built combining different variables represent one of the most promising and recent advancement. Concerning the modeling techniques, analyses on small areas generally allow for the use of physically based models, while statistical models are widely used for larger areas.
This session focuses on LEWS at all scales and stages of maturity (i.e., from prototype to active and dismissed ones). Test cases describing operational application of consolidated approaches are welcome, as well as works dealing with promising recent innovations, even if still at an experimental stage. The session is not focused only on technical scientific aspects, and submissions concerning practical and social aspects are also welcome.

Contributions addressing the following topics will be considered positively:
- conventional and innovative slope-scale monitoring systems for early warning purposes
- conventional and innovative regional prediction tools for warning purposes
- innovative on-site instruments and/or remote sensing devices implemented in LEWS
- warning models for warning/alert issuing
- operational applications and performance analyses of LEWS
- communication strategies
- emergency phase management