Principles of developing a procedure to assess consequences of natural and climatic changes for transport infrastructure facilities in permafrost regions

Abstract

Abstract A structure of the procedure to assess climatic risks in Russian northern territories is proposed and justified. Facility functionality is defined by the state of permafrost soil in its bed. To quantitatively assess the state, state parameters are used (one or several) each having an established range of acceptable states. Facility functionality reduction is assessed depending on the distance between the state parameter value and the boundary of the acceptable state range. Dynamics of changes in the state parameter during a year is assessed by modeling permafrost soil temperature conditions. To model the climate condition, an average statistical year is used, which reflects the overall climatic trend in this area and which is free from strong annual variation of climatic manifestations; within an average statistical year, climatic parameters are defined by averaging over a sufficiently long period of time. A probabilistic nature of climatic risks is conditioned by invariable uncertainties in relation to future climatic parameters; to take those uncertainties into account, future climatic parameters are suggested to be described using random values. A quantitative risk assessment is performed using statistical modeling methods where reference data are a multitude of probabilistic climatic parameters and determined parameters reflecting physical, mechanical and thermal physical characteristics of permafrost soil as well as characterizing heat flows between soil and facility elements located in it. The results of numerical modeling of permafrost soil temperature conditions, obtained for the existing and predicted climatic conditions of Norilsk, show adequacy and efficiency of the suggested procedure and prove a substantial hazard of climate warming for infrastructure facilities located on permafrost soils.