Monitoring the Thaw Slump-Derived Thermokarst in the Qinghai-Tibet Plateau Using Satellite SAR Interferometry

Bo Hu,Xiongle Chen,Zhiwei Chen,Bing Yang,Xingfu Zhang,Hui Li,Junyu Chen,Yang Wu

doi:10.1155/2019/1698432

Abstract

Thaw slumps are well-developed within a 10 km wide zone along the Qinghai-Tibet engineering corridor, especially along the Qinghai-Tibet highway and railway. Previous studies have focused on thaw slump instability such as its origin development, headwall retrogression rate, failure scale, and thermal regime, yet the intrinsic dynamic process of surface movement is relatively less known. In this study, we used InSAR based on the L-band ALOS PALSAR images acquired from January 2007 to October 2010 to investigate the distribution of thaw-induced slope failures containing retrogressive thaw slumps and active layer detachment failures along the Qinghai-Tibet highway (QTH). Our InSAR analysis reveals that the maximum annual average sedimentation rates are even up to -35 mm·yr−1 in the slope direction to the K3035 thaw slump, and the K3035W active layer detachment failure developed on the west side of K3035. The distribution, failure extent, and stability of the slope failures obtained by our InSAR analysis all agree well with the field investigations. Our study illustrates that InSAR is an effective tool for studying the distribution and processes of the thaw slump-derived thermokarst and provides useful references for evaluating permafrost degradation in response to climate warming and external disturbance on the Qinghai-Tibet plateau.

Highlights

Permafrost degradation is an important indicator of global warming, which has drawn considerable attention in recent decades
Since the thaw slump deformation mainly occurs along the slope direction, the SBAS-derived deformation was transformed from the line of sight (LOS) into the slope direction
We investigated the distribution of thaw-induced slope failures and analyzed the temporal dynamics and spatial variability of the K3035 and K3035W thaw slumps along the Qinghai-Tibet highway (QTH) in the Beiluhe section based on SBAS method

Summary

Introduction

Permafrost degradation is an important indicator of global warming, which has drawn considerable attention in recent decades. Global warming over the last century and further warming in the following long period of time are an indisputable fact according to the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4, Acquired from IPCC Report: https://www.ipcc.ch/reports/) [1]. Qinghai-Tibet plateau (QTP) permafrost is characterized by low-middle latitude, high altitude, and high ground temperature compared to polar permafrost which seems to be more susceptible and vulnerable to climate change and external disturbance [2]. Under climatic and humaninduced disturbance, plateau permafrost has been undergoing strong warming and degradation. Thermokarst landforms are important indicators of permafrost degradation, which result from the thawing of ice-rich permafrost or melting of massive ground ice followed by surface subsidence results in irregular, depressed landforms. Thermokarst landforms are common in permafrost regions of the QTP. Thermokarst landforms on the QTP, especially nonlake ones, are seldom studied and poorly understood [4]

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Discussion

Conclusion