Understanding seismic risk in Santiago de Cali (Colombia) for its application in risk management

This study presents the results of the seismic risk assessment for the city of Santiago de Cali (Colombia), a collaborative effort between the Mayor's Office of Santiago de Cali (including the Municipal Planning Office and the Disaster Risk Management Secretariat), the Colombian Geological Survey (SGC), the United States Geological Survey (USGS), EAFIT University and the GEM Foundation. The primary objective was to provide actionable insights for Disaster Risk Management (DRM) across its stages: awareness, risk reduction, and disaster response, and to enable the creation of a risk assessment specifically tailored to the city's needs, ensuring that its results can be effectively integrated into local risk management processes. Early engagement with stakeholders ensured that the models aligned with local needs, facilitating their integration into DRM policies. The seismic risk analysis utilizes the latest hazard model developed for Colombia, advanced non-linear site effects characterization, and a detailed building inventory with local expertise. For the first time, data-driven deterministic and probabilistic seismic risk estimates are presented for the city. The results indicate that destructive events could heavily impact the city, particularly events coming from the Dagua-Calima Fault or Nazca Plate subduction zone . Moreover, probabilistic outcomes show that human casualties and building damage disproportionally affect low-income areas, while almost 50 % of economic losses occur to middle-to high-income areas due to higher asset values. These findings highlight the importance of risk reduction strategies that address simultaneously the physical vulnerability and socio-economic disparities. • Comprehensive Seismic Risk Assessment: A detailed analysis of seismic hazard, building exposure and physical vulnerability for the city of Santiago de Cali, Colombia. • Advanced Modelling Techniques: Simulation of seismic scenarios for the city, considering local faults and ground shaking amplification using tailored amplification functions. • Novel Risk Communication Strategies: Scenario response and risk mitigation profiles highlighting potential impact and high-risk communities to support awareness and risk management. • Implementation of Results in Disaster Risk Management: Seismic risk assessment results were used for the formulation and updating of the Santiago de Cali Risk Management Plant (PGRD) and the Municipal Emergency Response Strategy (EMRE).