A new approach to the assessment of natural risks for pipelines

Abstract

For many times, the authors participated in the projects on designing and construction of main pipelines in the Russian north. Accumulated experience brought us to the understanding that the available methods aimed at the assessment of natural risks for pipelines [1, 4-6, 12, 13] have sufficient drawbacks. These methods base on the correlation between the registered accidents and unique landscape units or different Quaternary deposits, thus, the results are hardly comparable and poorly adapted to the GIS of other projects. The comparison of accident rates on pipelines in Russia and the US also does not look quite correct. These difficulties relate to the absence of the single methodological base and uniform indicators for the risks assessment. We offer a new approach based on the system-morphological concept by A. Lastochkin. This concept involves building a geometrically precise model of the Earth’s surface, which is divided into a finite set of elements and their parameters. The assessment of natural risks for pipelines within these elements allows receiving standardized results that are sufficiently good for the forecast. In our research, we used the database of the National Pipeline Mapping System (USA). We divided all the accidents from the database, according to the accident reports, into two groups: 1) accidents caused by natural factors and 2) accidents of another origin. Then we analyzed the first group of accidents by nine key parameters and indicators: 1) altitude, 2) relative height, 3) steepness, 4) vertical curvature, 5) horizontal curvature, 6) exposition of the slopes, 7) proximity to structural lines, 8) type of elementary facet of the Earth’s surface, and 9) its length. We included seven northern states of the US in the analysis and obtained the reasonable picture of the influence of geomorphological conditions on the accident rate. We are going to continue these studies, to involve the factor analysis and the accidents forecast. The expected outcomes can be utilized by the designing of new pipelines on various territories.