Temporal Multilayer Hypergraph Model of Cross-Sector Dependencies and Cascading Disruptions in Smart-Region Critical Infrastructure

The paper proposes a temporal multilayer hypergraph model of interdependent critical infrastructure in a smart region. It combines five layers, seven dependency classes, a lattice of critical-function states, thresholds, reserves, and delays. The methods include set and relation theory, temporal hypergraphs, causal and ontological modelling, and scenario counterexamples. A synthetic four-sector topology contains 46 assets, 18 critical functions, and 64 temporal hyperedges, including 27 cross-sector hyperedges. In scenario K1, disruption reached four sectors and six functions within 55 minutes. In K2, a mean service level of 0.87 masked a function failure, whereas supremum-based aggregation recorded the emergency state. The integral resilience index was 0.71 against a baseline of 1.00; cross-sector dependencies accounted for 0.20 of the 0.41 loss before compensation. All quantitative results are synthetic and demonstrative. The model provides a basis for a regional digital twin, incident-consequence forecasting, and recovery coordination.