Abstract
The Qinghai-Tibetan plateau (QTP), also known as the Third Pole and the World Water Tower, is the largest and highest plateau with distinct and competing surface and subsurface processes. It is covered by a large layer of discontinuous and sporadic alpine permafrost which has degraded 10% during the past few decades. The average active layer thickness (ALT) increase rate is approximately 7.5 cm·yr−1 from 1995 to 2007, based on soil temperature measurements from 10 borehole sites along Qinghai-Tibetan Highway, and approximately 6.3 cm·yr−1, 2006–2010, using soil temperature profiles for 27 monitoring sites along Qinghai-Tibetan railway. In this study, we estimated the ALT and its AL thickening rate in the northern QTP near the railway using ALOS PALSAR L-band small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) data observed land subsidence and the corresponding ALT modeling. The InSAR estimated ALT and AL thickening rate were validated with ground-based observations from the borehole site WD4 within our study region, indicating excellent agreement. We concluded that we have generated high spatial resolution (30 m) and spatially-varying ALT and AL thickening rates, 2007–2009, over approximately an area of 150 km2 of permafrost-covered region in the northern QTP.
Highlights
Permafrost is defined as the perennially frozen soil that remains at or below the freezing point of water for at least two years [1]
We applied the SBAS-InSAR technique, which is described in Section 3, to monitor the secular land Remote surface deformation along the Qinghai-Tibetan railway (QTR) in the northern Qinghai-Tibetan plateau (QTP)
We found that the surface deformation in the frozen soil area was characterized by a cycle in each year, which means that surface deformation in the frozen soil area was characterized by a cycle in each year, which means subsidence and uplift occurred alternately within one year
Summary
Permafrost is defined as the perennially frozen soil that remains at or below the freezing point of water for at least two years [1]. The permafrost regions occupy approximately 24% (~23 × 106 km2 ) of the exposed land area in the Northern Hemisphere terrestrial region [2]. Permafrost is usually found in Remote Sens. Overlying the permafrost is the active layer (AL), which is the top layer of soil or other Earth materials that are subject to seasonal thawing during summer and freezing again during autumn. The AL thickness (ALT), the thaw depth in permafrost regions due to solar heating of the surface, is extremely sensitive to climate change. The permafrost temperature in Northern Alaska has increased by 2–3 ◦ C since the
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
