A BERT-CRF and Case-Crossover Framework for Evaluating Tourism Risk and Warning System Performance in Sichuan, China

Improving the precise perception of disaster risk and evaluating the effectiveness of warning systems are essential for natural-hazard prevention, mitigation, and spatial risk management. Using Sichuan Province, China, as a case study, this study treats government-issued disaster warning texts within 72 h before accident occurrence as formal risk signals and spatiotemporal information sources. Drawing on the protective action decision model and risk communication theory, we propose an integrated framework combining BERT-CRF-based information extraction, spatiotemporal analysis, and a case-crossover design to evaluate a multi-level warning system through the chain of risk identification, risk communication, protective action, and risk outcome. The results show a clear gradient across warning levels. High-level warnings are significantly associated with lower accident risk, whereas lower-level warnings can identify risky contexts but have limited intervention effects. These findings indicate that disaster warning systems have dual functions of risk identification and intervention, while medium-level warnings may reveal a weak link in the transition from risk perception to protective action. The study provides a geospatial analytical framework for linking official warning information with tourism safety outcomes and offers empirical support for optimizing warning systems and strengthening hazard risk governance in high-risk regions.