Thaw Subsidence of a Yedoma Landscape in Northern Siberia, Measured In Situ and Estimated from TerraSAR-X Interferometry
Thaw Subsidence of a Yedoma Landscape in Northern Siberia, Measured In Situ and Estimated from TerraSAR-X Interferometry
复制标题
西伯利亚北部耶多马景观的解冻沉降，现场测量并通过 TerraSAR-X 干涉测量进行估算
DOI：
10.3390/rs10040494
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
J. Boike
中科院分区：
文献类型：
--
作者：
S. Antonova;H. Sudhaus;T. Strozzi;S. Zwieback;A. Kääb;B. Heim;M. Langer;Niko Bornemann;J. Boike
在多年冻土区，季节性冻融循环导致地面上下移动。在过去十年中，一些永久冻土区报告了长期的下降趋势。2013-2017年，我们使用安装在永久冻土深处的参考棒测量了西伯利亚Lena河三角洲Yedoma地区的季节性和多年地面运动。2013年冷夏和2014年暖夏的季节性下沉分别为1.7 ± 1.5 cm和4.8 ± 2 cm。此外，从2013年春季到2017年夏末，我们测量了9.3 ± 5.7 cm的明显多年净沉降。重要的是，我们观察到一个高的空间变异沉降高达6厘米，在一个亚米级的水平尺度。在2013年夏天，我们伴随着我们的现场测量与差分合成孔径雷达干涉测量（DInSAR）的重复通过TerraSAR-X（TSX）的数据从2013年夏天，以检测夏季融化沉降在同一研究领域。干涉测量受到快速相位相干性损失、大气伪影以及可能的参考点选择的强烈影响。累积地面运动图，建立从连续的干涉叠加，没有显示在高地上的沉降，但显示了一个明显的沉降高达2厘米，在大多数的热岩溶盆地。在那里，DInSAR测得的沉降的空间模式与高分辨率光学图像的近红外波段确定的相对表面湿度相对应。我们的研究表明，（i）虽然X波段SAR在冻土景观的地面运动监测有严重的局限性，它可以提供有价值的信息，为特定的环境，如热岩溶盆地，和（ii）由于地面运动的高亚像素空间变异性，验证计划需要开发和实施未来DInSAR研究在冻土环境。
In permafrost areas, seasonal freeze-thaw cycles result in upward and downward movements of the ground. For some permafrost areas, long-term downward movements were reported during the last decade. We measured seasonal and multi-year ground movements in a yedoma region of the Lena River Delta, Siberia, in 2013–2017, using reference rods installed deep in the permafrost. The seasonal subsidence was 1.7 ± 1.5 cm in the cold summer of 2013 and 4.8 ± 2 cm in the warm summer of 2014. Furthermore, we measured a pronounced multi-year net subsidence of 9.3 ± 5.7 cm from spring 2013 to the end of summer 2017. Importantly, we observed a high spatial variability of subsidence of up to 6 cm across a sub-meter horizontal scale. In summer 2013, we accompanied our field measurements with Differential Synthetic Aperture Radar Interferometry (DInSAR) on repeat-pass TerraSAR-X (TSX) data from the summer of 2013 to detect summer thaw subsidence over the same study area. Interferometry was strongly affected by a fast phase coherence loss, atmospheric artifacts, and possibly the choice of reference point. A cumulative ground movement map, built from a continuous interferogram stack, did not reveal a subsidence on the upland but showed a distinct subsidence of up to 2 cm in most of the thermokarst basins. There, the spatial pattern of DInSAR-measured subsidence corresponded well with relative surface wetness identified with the near infra-red band of a high-resolution optical image. Our study suggests that (i) although X-band SAR has serious limitations for ground movement monitoring in permafrost landscapes, it can provide valuable information for specific environments like thermokarst basins, and (ii) due to the high sub-pixel spatial variability of ground movements, a validation scheme needs to be developed and implemented for future DInSAR studies in permafrost environments.
影响因子：
5.2
作者：
Guenther, F.;Overduin, P. P.;Grigoriev, M. N.
通讯作者：
Grigoriev, M. N.