Uncertainty Quantification and Sensitivity Analysis of High-altitude Electromagnetic Pulse Response of Buried Pipelines Based on the Stochastic Collocation Method

High-altitude electromagnetic pulse (HEMP) can induce current and voltage on buried oil and gas pipelines, which may pose a threat to the pipeline's safe operation. In order to fully consider the simultaneous change of input variables on the HEMP response, an uncertainty quantification model of the induced current based on the stochastic collocation (SC) method is proposed. Taking the elevation angle, the azimuth angle, and the field source azimuth angle as input variables, the uncertainty quantification of the response current of buried pipelines has been carried out. To improve the efficiency of uncertainty quantification, the sensitivities of the response current to input variables have been analyzed using the SC and Sobol global sensitivity indexes. The dimension of the input variables was decreased based on the sensitivity ranking, and the accuracy of the computed results after dimensionality reduction was checked through comparison. The uncertainty analysis methods and relevant conclusions can provide a reference for the electromagnetic pulse protection of the buried pipelines.