From PTHA to Probability of Safe Evacuation: An Agent-Based Modelling (ABM) Use Case for EPOS Integrated Core Services - Distributed

This work introduces a methodology that links Probabilistic Tsunami Hazard Analysis (PTHA) with social-behavioral simulation to support risk-informed decision-making, where safe evacuation probabilities are evaluated by integrating hazard likelihood with agent-based estimates of evacuation success or failure. The proposed model integrates heterogeneous digital assets, including probabilistic hazard scenarios, exposure datasets and statistically derived behavioral parameters, within a unified workflow, with several inputs already available or foreseen through the EPOS data portal. The methodological core follows a Probabilistic Tsunami Risk Assessment (PTRA) formulation and is embedded within a Monte Carlo integration scheme, where evacuation metrics are derived from repeated simulations under random realizations of uncertain inputs.

From a digital infrastructure perspective, this work explores the set-up and requirements for developing a prototype model as a use case for the EPOS Integrated Core Services-Distributed (ICS-D). Execution of PTRA using ABM requires access to distributed computing resources to support large scale and large numbers of agent-based simulations, server-side storage for hazard scenarios and exposure datasets, and statistical analysis/machine learning tools for the semi-automated transformation of raw information into meaningful behavioral inputs. Simulation outputs and geospatial products are then generated through Python and GIS-compatible visualization workflows.

Looking ahead, such configuration offers a basis for a probabilistic tsunami evacuation modelling service capable of incorporating cascading multi-hazard effects, such as earthquake-induced damage that directly influences evacuation dynamics. By explicitly representing individuals, infrastructure, and their interactions within a shared environment, it enables iterative updating of time dependent conditions. This provides a natural pathway toward a Digital Twin–oriented framework for tsunami evacuation, supporting adaptive, decision-relevant risk analysis and align with the objectives of the Tsunami Thematic Core Service of EPOS.