Sergio Di Cave

Preliminary study on the transport of hazardous materials through tunnels

The risk associated to road and rail transportation of some hazardous materials along two routes, one including a significant portion in tunnels, and the other following the same path, but running completely in the open, is assessed. The results show that, for rail transport, no particular risk increase or mitigation is associated to the circulation of the dangerous goods through tunnels; on the contrary, for road transport, a risk increase is generally observed in the presence of tunnels. However, for LPG, the risk curve in the open lies above that in tunnels in the high frequency-low fatality zone, according to the different evolution of the accidental scenarios in the tunnel (assuming no ventilation). The transportation of liquefied nitrogen, not hazardous in the open but potentially asphyxiating in a tunnel, gives rise to a negligible risk when performed by rail, but to a not negligible one, when performed by road. These preliminary results focused on the risk for the exposed population, suggest that it may be unnecessary to limit dangerous goods circulation through rail tunnels, while, at least for some types of dangerous goods, the circulation through road tunnels may be allowed/forbidden based on the results of a specific risk analysis.

Computer aided transportation risk assessment

The assessment of the hazard represented by the transportation of dangerous goods is the only reasonable basis for any policy of risk management and reduction. The use of such a quantitative approach, on the other hand, requires both the acquisition and the manipulation of a very large number of information: these steps are always time-consuming and seldom very accurate, since the need of limiting the calculation burden generally imposes the use of simplifying assumptions. This work presents a computer aided approach to transportation risk analysis coupling a risk assessment program with a Geographic Information System (GIS), providing accurate local information. The obtained benefits are more accurate risk estimates, a substantial cut of the time required to perform the analysis, a simplification of the data input step, and the possibility of displaying the results on the area map, together with other information, useful in the case of an emergency (location of fire brigades stations, hospitals, etc.).

A GIS based Approach to Environmental Vulnerability

The paper proposes a method for assessing the environmental vulnerability in the surroundings of a hazardous establishment based on the use of Geographical Information Systems (GIS). This approach uses GIS data to identify and quantify the presence of the different environmental targets in the study area and probit functions derived from consequence analysis to assess the vulnerability of each target to the hazards as a function of their distance from the site. Vulnerability maps can be rapidly obtained for each environmental target, which may be combined, assigning proper weights to each element, to get the overall environmental vulnerability.