A multi-hazard framework to assess co-seismic ground instabilities scenarios. Application to a virtual test bed

The increasing complexity of climate-driven multi-risk scenarios requires a paradigm shift from isolated, sector-specific hazard management to holistic, integrated frameworks. This paper presents a scalable methodology developed within the RETURN project to model transiently triggered ground instabilities (GIs), specifically landslides and soil liquefaction, through integrated, multi-stage computational workflows, termed “tool-chains”. These tool-chains logically sequence static susceptibility assessments, time-dependent preparatory processes and transient triggering actions to dynamically generate high-fidelity, single and multi-hazard impact scenarios at regional scale. The proposed framework overcomes the impracticality of deploying highly datademanding, physically based models over broad regional areas, while preserving computational efficiency. The tool-chains are applied within a Virtual Test Bed (VTB), a highly parametrized digital ecosystem, specifically implemented in the RETURN project framework, of a generic high-risk territory to test the algorithmic robustness and the capacity of the tools to quantify impacts on synthetic exposure zones under severe seismic actions. Furthermore, here is reported a methodology that integrates and combines the cascading effects of spatially and temporally independent processes triggered by the same factor, to be possibly further coupled to study multihazard scenarios. This adaptable framework aims at bridging the gap between advanced scientific modelling and practical decision-making, providing an operational toolset capable of supporting both long-term, non-structural mitigation strategies and rapid, near-real-time hazard assessments under ongoing transient forcings.