ABSTRACT Monitoring land surface deformation is one of the most reliable approaches that can be used to study, manage and forecast several geohazards (such as subsidence, landslide, sinkholes, etc.) linked to either natural or anthropogenic driving forces. The importance of such tools becomes more visible in urban environments where hazards would have aggravated consequences. Within this framework, a combined in-situ and remote sensing monitoring approach, that can be used to support a physically based assessment of land surface deformations driven by subsurface perturbations in urban environments, is presented. The approach makes use of multidisciplinary interferometric-hydrogeological-geotechnical investigation techniques. The present study was conducted on a test site in Bucharest where the effects of subway tunnelling and associated dewatering works were investigated. A referencing network specifically designed to support the targeted physically based assessment was implemented in this area. The system consisted of a set of monitoring stations equipped with corner reflectors, inclinometric and piezometric tubes, and levelling benchmarks. This system was deployed for a one year long monitoring campaign of in-situ surveying (of groundwater level, land surface vertical deformation (topographical levelling) and vertical profiles with horizontal displacements in soil (inclinometer surveys)) and remote sensing surveying (X-band Synthetic Aperture Radar (SAR) images were acquired). The obtained in-situ measurements (horizontal and vertical surface deformations) were used to cross-reference remotely sensed (obtained using Persistent Scatterers Interferometry technique) temporal deformation (along the line of sight) profiles. The results show that even though the investigated tunnelling and dewatering works did not produce detectable surface deformations, the SAR displacement trends fitted the in-situ measurements within a root mean square error of 1.5 to 4.8 mm, and thus the remote sensing approach proved again to be a reliable alternative to in-situ measurements for an adequate assessment of land surface deformation in urban and potentially non-urban environments.

中文翻译：

---

结合原位和持续散射干涉测量合成孔径雷达 (PSInSAR) 监测城市环境中的地表变形 - 案例研究：布加勒斯特（罗马尼亚）的隧道工程

摘要 监测地表变形是最可靠的方法之一，可用于研究、管理和预测与自然或人为驱动力相关的多种地质灾害（如沉降、滑坡、天坑等）。这些工具的重要性在城市环境中变得更加明显，因为在这些环境中，危险会带来更严重的后果。在此框架内，提出了一种结合原位和遥感监测方法，可用于支持对城市环境中地下扰动驱动的地表变形进行基于物理的评估。该方法利用了多学科干涉-水文地质-岩土工程调查技术。目前的研究是在布加勒斯特的一个试验场进行的，在那里调查了地铁隧道和相关脱水工程的影响。在该领域实施了专门设计用于支持有针对性的基于物理的评估的参考网络。该系统由一组配备角反射器、测斜管和测压管以及水平基准的监测站组成。该系统用于为期一年的现场测量（地下水位、地表垂直变形（地形平整）和土壤水平位移的垂直剖面（测斜仪测量））和遥感测量（X 波段）监测活动。合成孔径雷达 (SAR) 图像已获得）。获得的原位测量（水平和垂直表面变形）用于交叉参考遥感（使用持续散射干涉测量技术获得）时间变形（沿视线）轮廓。结果表明，即使调查的隧道和脱水工程没有产生可检测的地表变形，SAR 位移趋势在 1.5 至 4.8 毫米的均方根误差范围内符合现场测量，因此遥感方法再次证明是对城市和潜在的非城市环境中地表变形进行充分评估的现场测量的可靠替代方案。