Assessment of Freeze–Thaw Hazards and Water Features along the China–Russia Crude Oil Pipeline in Permafrost Regions

Mingtang Chai,Yanhu Mu,Yapeng Cao,Jun Zhang,Dun Chen,Qingsong Du,Wei Ma,Zhiwei Zhou,Yu Zhou,Guoyu Li,Gang Wu

doi:10.3390/rs12213576

Abstract

The China–Russia crude oil pipeline (CRCOP) traverses rivers, forests, and mountains over permafrost regions in northeastern China. Water accumulates beside the pipe embankment, which disturbs the hydrothermal balance of permafrost underlying the pipeline. Ground surface flows along the pipeline erode the pipe embankment, which threatens the CRCOP’s operational safety. Additionally, frost heave and thaw settlement can induce differential deformation of the pipes. Therefore, it is necessary to acquire the spatial distribution of water features along the CRCOP, and analyze the various hazard probabilities and their controlling factors. In this paper, information regarding the permafrost type, buried depth of the pipe, soil type, landforms, and vegetation were collected along the CRCOP every 2 km. Ponding and erosive damage caused by surface flows were measured via field investigations and remote sensing images. Two hundred and sixty-four pond sites were extracted from Landsat 8 images, in which the areas of 46.8% of the ponds were larger than 500 m2. Several influential factors related to freeze–thaw hazards and erosive damage were selected and put into a logistic regression model to determine their corresponding risk probabilities. The results reflected the distributions, and forecasted the occurrences, of freeze–thaw hazards and erosive damage. The sections of pipe with the highest risks of freeze–thaw and erosive damage accounted for 2.4% and 6.7%, respectively, of the pipeline. Permafrost type and the position where runoff encounters the pipeline were the dominant influences on the freeze–thaw hazards, while the runoff–pipe position, buried depth of the pipe, and landform types played a dominant role in erosive damage along the CRCOP. Combined with the geographic information system (GIS), field surveys, image interpretation and model calculations are effective methods for assessing the various hazards along the CRCOP in permafrost regions.

Highlights

The China–Russia crude oil pipeline (CRCOP) begins in Skovorodino, Russia, enters China in Xing’an, Mohe County, and terminates in Daqing, Heilongjiang Province
The normalized difference water index (NDWI) results were not used in our regression model, but they were used to ascertain the distribution of water bodies along the pipeline that were unreachable during the field survey
The main water features, which are the likely sources of water infiltration and runoff seen along the CRCOP were ponds, thermokarst lakes, and runoff/drainage along the pipeline

Summary

Introduction

The China–Russia crude oil pipeline (CRCOP) begins in Skovorodino, Russia, enters China in Xing’an, Mohe County, and terminates in Daqing, Heilongjiang Province. The process of pavement used when constructing the CRCOP changed local landforms and the flow paths of runoff, which resulted in the appearance of ponds and water erosion on both sides of the pipe embankment. These hazards increase the risk of frost heave and thaw settlement along the pipeline [2]. The main freeze–thaw hazards along the CRCOP route are frost heave, thawing settlement, the formation of frost mounds, and damage caused by the use of ice pitons [4]. Seasonal frost mounds 1–1.5-m tall have appeared in regions with developed groundwater and ice-rich permafrost. Landslides can occur on a permafrost slope due to rainfall and freeze–thaw cycles, which may generate tensile forces on the pipeline [3,5]

Methods

Results

Discussion

Conclusion