Monitoring the Permafrost Conditions along Pipeline Routes in Central Yakutia, Russia

Abstract

Pipelines are critical infrastructure for Yakutia, transporting vital supplies to communities in this vast northern region. The pipeline routes in central Yakutia traverse areas of ice-rich permafrost that is sensitive to temperature changes. This study examined the thermal state of permafrost in undisturbed and disturbed settings along the Lena River to Mundulakh Reservoir water pipeline and the Mastakh to Yakutsk gas pipeline and considered the effects of climatic fluctuations and surface disturbances (forest removal and wildfire) over the monitoring periods of 28 and 18 years, respectively. The geocryological conditions in the study area, as well as the methods of permafrost thermal monitoring, are described. The observation results demonstrated significant increases in the mean annual ground temperature in the upper permafrost layers, as well as in the active-layer thickness following fire and post-fire clearing. At some sites, progressive deepening of the active layer caused the formation of taliks and reached the top of massive ground ice, initiating permafrost degradation. The development of extreme ground temperatures in the layer of annual temperature fluctuations was analyzed according to the combination of seasonal and annual meteorological conditions and the type of anthropogenic impact. The research results can be extrapolated to similar anthropogenic landscapes.

Transient Electromagnetic Monitoring of Permafrost: Mathematical Modeling Based on Sumudu Integral Transform and Artificial Neural Networks

“…It can be shown that the electric field strength obtained under similar conditions is the fundamental solution in time to problem ( 21)- (25). Accordingly, its Sumudu image in time satisfies (19) and (20). If the radii of the loops are sufficiently small compared to the distance between their centers, then the transmitter loop can be replaced with a vertical magnetic dipole; the EMF in the receiver coil can be taken to be proportional to the time derivative of the z-component of the magnetic field strength…”

“…We assume the current density in the loop J 0 (u) to be constant. Then, the right-hand side of (19) will correspond (up to sign) to the Sumudu image of the δ-function, which is equivalent to the stepwise switching on of the current at time t = 0. Thus, the solution to the boundary-value problem ( 19)- (20) will be the Sumudu image of the fundamental solution to problem ( 21)- (24) in time.…”

“…In this connection, timely monitoring and decision-making seem to be critical for the sustainable development and economy of Arctic and high-altitude cold regions. Among the target monitoring objects are: highways [8,9]; railway lines [10,11]; airport runways [12,13]; engineering constructions at oil [14] and gas [15] fields; thawing zones around production wells during hydrocarbon extraction [16,17]; oil and gas pipelines [18,19]; fuel storage tanks [20,21]; bridge foundations [22,23]; pile foundations of buildings [24,25]; power transmission lines [26,27].…”