Assessing cascading disaster impacts induced by interconnected natural hazards in Bosnia & Herzegovina

Bosnia and Herzegovina (BiH) is characterized by complex risks induced by natural hazards, particularly floods, landslides, and earthquakes. The recent flood and landslide disaster in the Herzegovina-Neretva Canton in October 2024 underscored the severe adverse impacts of cascading disasters on infrastructure, the economy, environment, and peoples’ wellbeing in BiH. Improved understanding of these cascading impacts, as well as their risk drivers, is hence an integral first step in enhancing climate and disaster risk management. Yet existing disaster risk and impact assessments often focus on single hazards or are tailored to specific, isolated impacts. 

Therefore, we applied a comprehensive, mixed-method risk assessment, to identify key risks, risk drivers, including hazard, exposure, and vulnerability factors, potential and observed disaster impacts, as well as cascades and interconnections across risk drivers and impacts. Our study focused on floods, landslides, and earthquakes in the Herzegovina-Neretva Canton in BiH, applying conceptual risk models, including impact chains and impact webs, with data derived from literature, expert interviews, field observations, and a dedicated workshop with local stakeholders. 

Our results provide evidence of a multi-hazard risk context, in which floods and earthquakes both increase the potential for landslides – with interconnected impacts. Direct impacts, such as physical damage to housing and infrastructure, represent only a portion of the total burden, while transport disruption and a short-term delay in emergency response reveal cascading impacts. Tangible costs are further compounded by intangible effects, including displacement-related well-being losses as a consequence of destroyed buildings even up to one year after the disaster. At the same time, various risk drivers in the system can critically amplify these impact cascades. 

By considering hazard interactions, as well as short- and long-term impacts across diverse sectors, the conceptual risk models provided new evidence that disaster impacts are systematically underestimated when cascading and intangible effects, and the interconnection of risk drivers remain unaccounted for. The development of a multi-hazard conceptual risk model represents an effective approach to move to systemic disaster risk management, while providing specific entry points for interventions.