Framing Uncertainty in Pipeline Geohazard Assessment for Integrity Management and Iterative Risk Assessment

Pipeline geohazard assessment is becoming recognized by operators and regulators as an increasingly important constituent of overall integrity management and iterative risk assessment of pipelines. An ongoing challenge in assessing the threat posed to a pipeline by various geohazard mechanisms within the B31.8S category of Weather-related and Outside Force is the degree of uncertainty associated with estimates of frequency of occurrence, vulnerability, and loss of containment for individual and cospatial geohazard mechanisms. When combined with threats of other types, such as corrosion and third party damage, estimates of geohazard occurrence frequency and their associated frequency (or probability) of loss of containment may seem imprecise and uncertain. This paper discusses a framework for assessing geohazard susceptibility and the associated uncertainty, and means of incorporating and communicating uncertainty in hazard and risk assessments. Examples are provided from a case study in Perú.