In recent years, significant efforts have been dedicated to evaluating urban risks stemming from individual natural hazards. However, the comprehensive assessment of potential cumulative impacts resulting from multiple hazards, a crucial aspect in the context of urban resilience, remains largely unexplored in both research and urban management practices.

Urban risk constitutes a complex matrix encompassing various elements at risk, including people, buildings, and infrastructure, coupled with multiple types of hazards, such as geophysical, meteorological, and hydrological, among others. Some hazard processes share drivers from both internal and external geodynamic forces of the Earth, while others occur in a cascade, following the triggering of a hazard not directly related to them. Further complexity arises from the need to consider multiple temporal scales, including both present and future time points, as well as various types of vulnerabilities. Efficient and people-centred risk management strategies rely on understanding and monitoring these interactions to provide timely, accurate, and actionable information. Therefore, exploring the complex interconnections among these factors is crucial. A thorough understanding of multi-hazard risk not only helps prioritise initiatives aimed at enhancing urban resilience but also lays the groundwork for re-examining institutional frameworks. This, in turn, enhances the adaptability of buildings and populations to the impacts of natural and anthropogenic hazards.

The present Special Issue aims to contribute to the advancement of this field by compiling a collection of high-quality contributions that collectively represent the current state of the art and provide insights into its future direction. It comprises nine research articles co-authored by leading researchers from twelve countries across four continents, which together reflect a diverse range of methodologies and perspectives, highlighting the interdisciplinary nature of the field and underscoring the importance of collaborative research in assessing and mitigating multi-hazard risks in urban environments. These articles are listed below in chronological order of publication, with their key objectives and conclusions briefly summarised.

In the article “Under the rubble: disaster risk management and accountability after the Mexico City earthquake of September 19, 2017,” Alcántara-Ayala et al. (2022) analyse the aftermath of the September 19, 2017, Mexico City earthquake. In the paper, the authors shed light on the limited responses from local authorities, primarily focused on immediate actions post-earthquake, employing traditional approaches. Among other aspects, this work emphasises how immediate post-earthquake actions, while commendable, have been increasingly seen as a cause of concerns about the accountability of authorities responsible for civil protection and risk management at various levels of government.

In “Increasing resilience to catastrophic near-field tsunamis: systems for capturing, modelling, and assessing vertical evacuation practices,” León et al. (2023) explore the potential of vertical evacuation buildings in tsunami-prone areas. Integrating various aspects such as shelter siting, evacuee decision-making, and agent-based models, this research demonstrates the potential efficacy of vertical evacuation in minimising human losses. However, it also highlights the necessity of comprehensive public education campaigns to ensure optimal utilisation and effectiveness of vertical evacuation strategies in real-world scenarios.

In “Can we pull resilience from the rubble? Experiencing earthquakes in Mexico City,” Alcántara-Ayala et al. (2023) discuss the discrepancy between theoretical resilience strategies and their practical implementation. Using the impact of the September 19, 2017, Mexico City earthquake as a motto, the authors discuss the real-world efficacy of the diverse resilience-building strategies adopted under the 100 Resilient Cities program. Among other relevant observations, the authors stress the need for a nuanced understanding of resilience dynamics and the challenges in translating resilience frameworks into tangible outcomes amidst seismic events.

In “Methodology to incorporate seismic damage and debris to evaluate strategies to reduce life safety risk for multi-hazard earthquake and tsunami,” Amini et al. (2023) present a methodology to evaluate life safety risk of coastal communities vulnerable to seismic and tsunami hazards. The methodology proposed in this paper integrates seismic damage assessment and evacuation modelling, highlighting the pivotal role of mitigation strategies in minimising fatalities and associated risks. By showcasing the efficacy of seismic retrofitting as a viable risk reduction strategy, this research underscores the importance of proactive measures in disaster-prone regions.

In “Multi-vulnerability analysis for seismic risk management in historic city centres: an application to the historic city centre of La Serena, Chile,” Baquedano-Juliá et al. (2023) propose a holistic approach to assess seismic vulnerability in historic centres. Using the historic city centre of La Serena, Chile, as a case study, the authors introduce and discuss the application of two vulnerability indices that assess vulnerability across physical and social dimensions. By map** vulnerability levels, this research offers a replicable model for similar historic centres worldwide, emphasising the importance of considering both physical and social dimensions in seismic risk assessment and management.

In “Analysing diurnal temperature range and extreme temperature events over Delhi and Mumbai mega cities,” Shahfahad et al. (2023) investigate the changing thermal environments in urban landscapes. Highlighting declining diurnal temperature ranges and increasing extreme temperature events in Delhi and Mumbai, this research underscores the challenges faced by urban dwellers in terms of heat vulnerability and declining thermal comfort—a topic that, as discussed by the authors, is of the utmost importance for formulating targeted interventions aimed at mitigating the direct and indirect impacts of high temperatures in mega cities.

In “Flood resilience assessment from the perspective of urban (in)formality in Surat, India: Implications for sustainable development,” Jamshed et al. (2023) evaluate resilience disparities between formal and informal settlements in Surat, India. The authors analyse differences in physical and institutional resilience, highlighting targeted strategies to bridge these gaps for sustainable urban development and propose a series of resilience-enhancement and strengthening measures tailored to the needs of both formal and informal settlements. Ultimately, this work aims to provide guidance to disaster managers and policymakers by advocating for a strategic and targeted approach to strengthen resilience and achieve sustainable development.

In “Approaching the challenge of multi-phase, multi-hazard volcanic impact assessment through the lens of systemic risk: application to Taranaki Mounga,” Weir et al. (2024) introduce an innovative framework aimed at enhancing volcanic disaster risk management, in which multi-phase scenarios temporally alternate between different volcanic hazards and opportunities for risk reduction. This investigation addresses the challenges of assessing volcanic risk, emphasising the complex, multi-hazard nature of volcanic eruptions and the dynamic vulnerability before, during, and after such events. Focusing on interdependent critical infrastructure networks in the Taranaki region, where the Taranaki Mounga volcano poses significant eruption risk, this research identifies optimal timings for implementing mitigation strategies during an evolving eruption.

Finally, in “Landslide susceptibility assessment using different rainfall event-based landslide inventories,” Oliveira et al. (Oliveira et al. 2024) address the challenges of understanding the relation between distinct types of rainfall events and the resulting slope instability. They separately applied a historical landslide inventory and two inventories of slope movements triggered by two contrasting rainfall patterns—the short-period 1983 and the long-period 2010 storms in the Lisbon region, Portugal. The study also revealed how the same seven predisposing conditions (related to lithology, soil, and morphology) behaved when modelled according to the Informative Value susceptibility method.

The editors would like to express their sincere gratitude to the journal’s editorial office, particularly Professor James Goff, whose exceptional and unwavering support proved invaluable, to all the authors who generously shared their valuable knowledge and insights through their outstanding contributions, and to the many reviewers involved in the peer-review process of the papers, whose rigorous evaluations significantly contributed to the excellence of this editorial project.