A decision criterion based on the feeling of danger in risk situation

Mathematical modelling of the risk of events of small probability and large damage has always been a difficult problem. Nowadays it is more and more inevitable to consider laymen's opinion in such situations. The formulation to be created should be in accordance with laymen's feeling of danger. The model discussed in the paper approaches the mathematical description of risk from the viewpoint of the public opinion, using the results of experimental psychology in the form of general stimulus–response laws. Laymen's feeling of danger is in connection with the entropy of the source of information formed by the sequence of occurred catastrophic events. The aim of the paper is the establishment of a decision criterion, which would help in substantiating technical-economic decisions while satisfying the above demands. The criterion is illustrated on two real-life examples taken from hydraulic engineering.