Ghorbani Zahra, Khosravi Ali, Maghsoudi Yasser, Mojtahedi Farid Fazel, Javadnia Eslam, Nazari Ali
Faculty of Geodesy and Geomatics Engineering, K. N. Toosi University of Technology, Tehran, Iran.
Department of Civil and Environmental Engineering, Auburn University, Auburn, AL, USA.
Sci Rep. 2022 Aug 17;12(1):13998. doi: 10.1038/s41598-022-17438-y.
The Ardabil plain, with an approximate area of 1097.2 km in northwestern Iran, has experienced land subsidence due to intensive groundwater withdrawal and long seasons of drought in recent years. Different techniques have been used to investigate and evaluate subsidence in this region including: Global Positioning Systems (GPS), Levelling, and Geotechnical methods. These methods are typically expensive, time-consuming, and identify only a small fraction of the areas prone to subsidence. This study employs an Interferometric Synthetic Aperture Radar (InSAR) technique to measure the long-term subsidence of the plain. An open-source SAR interferometry time series analysis package, LiCSBAS, that integrates with the automated Sentinel-1 InSAR processor (COMET-LiCSAR) is used to analyze Sentinel-1 satellite images from October 2014 to January 2021. Processing of Sentinel-1 images shows that the Ardabil plain has been facing rapid subsidence due to groundwater pumping and reduced rainfall, especially between May 2018 to January 2019. The maximum subsidence rate was 45 mm/yr, measured at the southeastern part of the plain. While providing significant advantages (less processing time and disk space) over other InSAR processing packages, implementation of the LiCSBAS processing package and its accuracy for land subsidence measurements at different scales needs further evaluation. This study provides a procedure for evaluating its efficiency and accuracy for land subsidence measurements by comparing its measurements with the results of the GMTSAR and geotechnical numerical modeling. The results of geotechnical numerical modeling showed land subsidence with an average annual rate of 38 mm between 2006 and 2020, which was close to measurements using the InSAR technique. Comparison of the subsidence measurements of the Ardabil plain using the LiCSBAS package with results obtained from other techniques shows that LiCSBAS is able to accurately detect land deformation at large scales (~ km). However, they may not be optimized for more local deformations such as infrastructure monitoring.
阿尔达比勒平原位于伊朗西北部，面积约1097.2平方千米，近年来由于大量抽取地下水和长期干旱，该地区出现了地面沉降。人们运用了多种技术来调查和评估该地区的沉降情况，包括全球定位系统（GPS）、水准测量和岩土工程方法。这些方法通常成本高昂、耗时费力，而且只能识别出一小部分容易发生沉降的区域。本研究采用干涉合成孔径雷达（InSAR）技术来测量该平原的长期沉降情况。使用一个与自动化哨兵-1 InSAR处理器（COMET-LiCSAR）集成的开源SAR干涉测量时间序列分析软件包LiCSBAS，来分析2014年10月至2021年1月的哨兵-1卫星图像。对哨兵-1图像的处理表明，由于抽取地下水和降雨减少，阿尔达比勒平原一直面临着快速沉降，特别是在2018年5月至2019年1月期间。最大沉降速率为每年45毫米，出现在平原的东南部。虽然与其他InSAR处理软件包相比，LiCSBAS处理软件包具有显著优势（处理时间和磁盘空间更少），但其在不同尺度上进行地面沉降测量的实施情况及其准确性仍需进一步评估。本研究通过将其测量结果与GMTSAR和岩土工程数值模拟的结果进行比较，提供了一种评估其在地面沉降测量方面的效率和准确性的程序。岩土工程数值模拟结果显示，2006年至2020年期间地面沉降的平均年速率为38毫米，这与使用InSAR技术的测量结果相近。将使用LiCSBAS软件包对阿尔达比勒平原沉降的测量结果与其他技术获得的结果进行比较表明，LiCSBAS能够准确检测大尺度（约千米）的地面变形。然而，它们可能未针对诸如基础设施监测等更局部的变形进行优化。
