Hazard and risk assessment of rainfall-induced landsliding along a railway line

The occurrence of landslides along a transportation route such as a railway line can have severe and even catastrophic consequences. The assessment and management of hazard and risk is, therefore, of paramount importance. This paper introduces an approach for assessing the hazard and risk of rainfall-induced landsliding along a 30 km section of railway track. Careful analysis is made of rainfall data for previous storms, which have led to widespread landsliding. The recurrence interval of a typical landslide triggering rainstorm is estimated. From this the annual probability of widespread landslide occurrence is then calculated. This value combined with information on the frequency of train operations enables the estimation of the annual risk of human casualty. This estimate is then compared with proposed tolerable or acceptable levels. Such a systematic quantitative procedure can facilitate efficient risk management. Moreover, the outcomes of the assessments proposed in this paper can be combined with information and analyses about the relative landslide susceptibility of different section of track based on knowledge of local geology, topography and other factors.