Quantifying the effect of early warning systems on natural hazard risk

Risk to persons caused by gravitationally driven site-specific natural hazards along traffic routes is frequently reduced with Early Warning Systems (EWS). To identify an optimal risk reduction strategy, decision-makers should be able to quantify the effectiveness and costs achieved with EWS and compare both to alternative mitigation measures. A recognized framework approach for quantifying the effectiveness of EWS is currently lacking. We provide such a framework approach, which includes six steps that enable a structured quantification of the effectiveness, from the reliability of the EWS. To this end, site specific EWS are distinguished in two classes and the reliability analyses are conducted according to specific needs with Bayesian Networks (BN).