Using Persistent Scatterer Interferometry to Map and Quantify Permafrost Thaw Subsidence: A Case Study of Eboling Mountain on the Qinghai‐Tibet Plateau

Abstract

Permafrost thaw subsidence, a key indicator of permafrost degradation, remains poorly quantified or understood. It is particularly challenging to detect and measure surface subsidence due to the loss of subsurface ice over a large area because it usually develops gradually, over several years or decades. Here we utilize the persistent scatterer interferometric synthetic aperture radar (PSI) approach to remotely measure gradual surface subsidence on Eboling Mountain in the northeastern region of the Qinghai‐Tibet Plateau, where thermal erosion gullies are well developed. Most of the previous multitemporal interferometric synthetic aperture radar studies on permafrost used the small baseline subset method. By contrast, the PSI approach benefits from the full spatial resolution and is less affected by temporal or geometric decorrelation. In the PSI analysis, we incorporate a piecewise elevation change model that includes periodic subsidence/uplift because of its seasonally varying components as well as its linear subsidence trends. Applying this permafrost‐designated PSI algorithm to 17‐L band ALOS‐1 PALSAR images taken between 2006 and 2011, we find that both the thermal erosion gullies and the surrounding regions (within about 300 m) subside gradually. The subsidence trends range from 0.3 to 3 cm/yr. This suggests that permafrost areas near the gullies are more vulnerable to gradual thawing and degradation. This study demonstrates the potential of using PSI to study permafrost thaw processes and of assessing its impacts over vast areas on the Qinghai‐Tibet Plateau and in the Arctic.

Surface displacement revealed by L-band InSAR analysis in the Mayya area, Central Yakutia, underlain by continuous permafrost

“…The inversion algorithm requires a sufficient number of interferograms to estimate an appropriate trend; however, the number of high-quality interferograms is often limited in some areas. Chen et al (2018b) first applied the PS-InSAR technique to ALOS/ PALSAR data to derive permafrost thaw subsidence in the Qinghai-Tibet Plateau with a rate ranging from 0.3 to 3 cm yr −1 using 17 scenes of ALOS. SAR images acquired during the snow-covered season were used in the study, which may include errors associated with snow accumulation.…”

“…Synthetic aperture radar (SAR) interferometry (InSAR) is a processing technique for detecting surface displacements that has been widely used in applications such as crustal deformation (e.g., Massonnet et al 1993) and glacier motion (e.g., Joughin et al 2010). SAR data have been recently used to monitor permafrost's related deformations in Alaska (Liu et al 2010(Liu et al , 2015Iwahana et al 2016a), Canada (Short et al 2011(Short et al , 2014, Lena Delta (Antonova et al 2018;Chen et al 2018a;Strozzi et al 2018), and Tibet (Chen et al 2018b). Liu et al (2015) used the Advanced Land Observing Satellite/Phased Arraytype L-band Synthetic Aperture Radar (ALOS/PALSAR) InSAR to reveal the thermokarst settlement near Deadhorse along the North Slope, Alaska.…”

“…They reported good L-band results with deeper penetration through vegetation that maintained coherence over time and space, indicating that L-band SAR has a notable advantage over X-band SAR in monitoring displacement. Many studies have targeted ground-surface displacement in periglacial landscapes using ALOS/PALSAR L-band InSAR (e.g., Short et al 2011;Chen et al 2013Chen et al , 2018bJia et al 2017;Dini et al 2019;Michaelides et al 2019). However, there have been a limited number of studies on the inter-annual measurements of thermokarst subsidence by L-band InSAR.…”

Time-Series InSAR Monitoring of Permafrost Freeze-Thaw Seasonal Displacement over Qinghai–Tibetan Plateau Using Sentinel-1 Data

“…Due to the global and seasonal temperature changes, without dominant scatter and phase variation, the backscattering and phase features of the ground targets in the permafrost region are significantly affected by spatial-temporal decorrelation, which obscures the underlying signal and limits the application of InSAR [19,20]. To reduce and overcome those limitations, MT-InSAR methods, including small baselines subset (SBAS) techniques [21], persistent scatter interferometry (PSI) techniques [22][23][24], and other PSI-and SBAS-like methods (Stanford method for persistent scatters (StaMPS) [19], temporally coherent point InSAR (TCP-InSAR) [25][26][27]) have been applied to numerous examples of surface displacement [12,[28][29][30]. Compared with conventional InSAR methods, MT-InSAR shows better performance in urban environments.…”

Remote Sensing of Environmental Changes in Cold Regions: Methods, Achievements and Challenges

“…The authors identified X-band backscatter time series as a useful tool complementing optical remote sensing and in situ monitoring for rapid analysis of tundra permafrost erosion along riverbanks and coastal areas. Chen et al [176] used Persistent Scatterer Interferometry (PSI) to map and quantify permafrost thaw subsidence in the Qinghai-Tibet Plateau. According to the authors, the PSI approach is less affected by temporal or geometric decorrelation, while their results indicated that permafrost areas near gullies are more vulnerable to gradual thawing and degradation.…”