scholarly journals Ground Subsidence Analysis in Tianjin (China) Based on Sentinel-1A Data Using MT-InSAR Methods

2020 ◽  
Vol 10 (16) ◽  
pp. 5514
Author(s):  
Dong Li ◽  
Xiyong Hou ◽  
Yang Song ◽  
Yuxin Zhang ◽  
Chao Wang

Multi-temporal InSAR (MT-InSAR) methods have been widely used in remote sensing monitoring of ground subsidence, which occurs at many places around the world. Land subsidence, caused by excessive extraction of groundwater, has always been a problem to be solved in Tianjin, China. Although the subsidence in the urban area has been controlled at a low rate, the subsidence issue has not been effectively solved in the suburban area recently, which should be paid much attention. This paper aims to present two multi-temporal differential interferometry techniques, persistent scatterer (PS) and small baseline subset (SBAS), for monitoring the latest surface subsidence in a Tianjin study area on the basis of 20 Sentinel-1A images obtained from March 2017 to March 2019. Our research showed that the average velocity map obtained from the SBAS method closely followed the outcomes of the PS technique from the perspective of identifying similar subsidence patterns. Subsidence rate gradually increased from the urban area of Tianjin to the suburbs and high subsidence zones were mainly distributed at the junction of the Wuqing, Xiqing and Beichen districts. In the past two years, the annual average subsidence rate in the high settlement area mostly exceeded −50 mm/year, which caused serious damage to local infrastructures. Besides, high-resolution remote sensing images combined with field investigations further verified the successful application of MT-InSAR technology in Tianjin’s subsidence monitoring. Effective ground subsidence control measures need to be taken as soon as possible to prevent the situation from getting worse.

2014 ◽  
Vol 14 (2) ◽  
pp. 247-257 ◽  
Author(s):  
S. V. Samsonov ◽  
P. J. González ◽  
K. F. Tiampo ◽  
N. d'Oreye

Abstract. Fast ground subsidence in southern Saskatchewan (Canada) between the city of Saskatoon and Rice Lake was observed with the RADARSAT-2 interferometric synthetic aperture radar (InSAR) during 2008–2011. We collected 23 ascending Multi-Look Fine 3 Far (MF3F) and 15 descending Standard 3 (S3) RADARSAT-2 images and performed time-series analysis utilizing Small Baseline Subset (SBAS) and Multidimensional SBAS (MSBAS) methodologies. We observed two well-defined circular regions located a few kilometers apart and subsiding with the nearly constant rate of about 10 cm yr-1. MSBAS decomposition revealed the presence of both vertical and horizontal ground displacements. For further analysis we selected two highly coherent interferograms spanning from November to December 2009 until April 2010 thanks to particularly favorable ground conditions that displayed superior coherence. We performed modeling and inversion assuming spherical and sill source models in order to determine the source location, depth and strength. The sill source model produced the smallest residual of 0.7 cm yr-1 applied to ascending interferograms and 0.9 cm yr-1 applied to descending interferograms. A residual of 1.0 cm yr-1 was achieved with the sill model when both ascending and descending interferograms were used. This model suggested sources located at 1.3 and 1.2 km depth with radius of 1.0 and 1.3 km for eastern and western areas, respectively. The spherical model suggested slightly shallower sources located at 0.9 and 0.8 km. We could not precisely identify the cause of this deformation, but the observed subsidence rate and source depth suggest mining-related origin. Topographic changes produced by this subsidence rate over a long time may produce shallow groundwater redistribution and flooding of agricultural lands.


2020 ◽  
Vol 153 ◽  
pp. 03007
Author(s):  
I Nyoman Sudi Parwata ◽  
Norikazu Shimizu ◽  
Bojana Grujić ◽  
Sabid Zekan ◽  
Ruža Čeliković ◽  
...  

Tuzla City, Bosnia and Herzegovina, is very famous for salt mining. The intensive extraction of brine from the underground salt deposit caused accumulative subsidence of up to -12 m from 1956 to 2003. It induced serious damage to residences, buildings, and infrastructures. Although the activity of brine extraction was officially stopped in 2007, reports of subsidence are still on-going for some areas of Tuzla City according to a previous study. In the present study, a satellite-based method, i.e., Differential Synthetic Aperture Radar (DInSAR), is applied for the subsidence monitoring of the induced underground brine extraction. Since October 2014, SAR data obtained by the Sentinel-1A and -1B satellites (European Space Agency: ESA) and Small Baseline Subset (SBAS) multi-temporal analyses have been employed to obtain the spatial distribution and the temporal transition of the land subsidence. The accuracy and effectiveness of the SBAS-DInSAR method are assessed and evaluated by using the real-time kinematic GNSS monitoring system. DInSAR detected that the subsidence is still on-going at a velocity of -36.4 mm/year in some areas, especially in an area northeast of the center of the city. This study presents the validity and effectiveness of SBAS-DInSAR as a useful subsidence monitoring tool.


2018 ◽  
Vol 10 (12) ◽  
pp. 2025 ◽  
Author(s):  
Lianhuan Wei ◽  
Yun Zhang ◽  
Zhanguo Zhao ◽  
Xiaoyu Zhong ◽  
Shanjun Liu ◽  
...  

The mining waste of open pit mines is usually piled-up in dump sites, making a man-made hill more than tens of meters high. Because of the loose structure of the dump sites, landslides or debris flow may occur after heavy rainfall, threatening local lives and properties. Therefore, dump stability analysis is crucial for ensuring local safety. In this paper, a collaborative stability analysis based on multiple remote sensing technologies was innovatively conducted at the Xudonggou dump of the Anqian iron mine. A small baseline subset (SBAS) analysis was used to derive the spatial and temporal distributions of displacements in the line-of sight (LOS) over the whole study area. The deformation in LOS is translated to the slope direction based on an assumption that displacements only occur parallel to the slope surface. Infrared Thermography (IRT) technology was used to detect weak aquifer layers located at the toe of possible landslide bodies. Then, numerical simulations based on the limit equilibrium method were conducted to calculate the factor of safety for three profiles located on the dump site. The results, emerging from multiple remote sensing technologies, were very consistent and, eventually, the landslide hazard zone of the Xudonggou dump site was outlined.


2017 ◽  
Vol 50 (3) ◽  
pp. 1693 ◽  
Author(s):  
I. Ilia ◽  
C. Loupasakis ◽  
P. Tsangaratos

The main objective of the present study was to investigate ground subsidence in the wider area of Farsala, western Thessaly basin, by means of remote sensing techniques and to identify potential geo environmental mechanisms that contribute to the development of the observed surface fractures affecting the site. In this context, a set of Synthetic Aperture Radar (SAR) images, acquired in 1995-2003 by the European Space Agency (ESA) satellites ERS1 and ERS2 and processed with the Persistent Scatterer Interferometry (PSI) technique by the German Space Agency (DLR) during the Terrafirma project, were evaluated in order to investigate spatial and temporal patterns of deformation. Groundwater table levels of three water boreholes within the research area were processed providing the mean piezometric level drawdown and the mean annual drawdown rate. In addition, a quantitative comparison between the deformation subsidence rate and the thickness of the compressible sediments was also performed. The outcomes of the present study indicated a clear relationship in the subsidence deformation rate and the groundwater fluctuation and also a correlation between the depth of the bedrock and the deformation subsidence rate. Overall, the multitemporal SAR interferometry (DInSAR) data are proved as a valuable and suitable technique for increasing knowledge about the extent and the rate of the deformations in the current study area, proved to be affected with an increasing intensity. 


2020 ◽  
Vol 12 (24) ◽  
pp. 4011 ◽  
Author(s):  
Riccardo Lanari ◽  
Diego Reale ◽  
Manuela Bonano ◽  
Simona Verde ◽  
Yasir Muhammad ◽  
...  

We present in this comment a Multi-Temporal SAR Interferometry (MT-InSAR) analysis showing that the results published by Milillo et al. (2019) in the Remote Sensing Journal, presenting the evidence of space geodetic observations relevant to displacements occurring before the collapse of the Morandi Bridge, happened in Genova (Italy) on the 14 August 2018, are questionable. In particular, we focus on the InSAR results obtained by Milillo et al. (2019) by processing the 3 m × 3 m resolution COSMO-SkyMed (CSK) data collected from ascending and descending orbits on the area of interest. These results, thanks to the high spatial resolution and the short revisit time characterizing this multi-orbit SAR dataset, represent the cornerstone of their analysis. The main findings of their study allow Milillo et al. to conclude that the InSAR processing of this COSMO-SkyMed dataset reveals the increased deformation magnitude over time of points located near the strands of the deck next to the collapsed pier, between 12 March 2017 and August 2018. In this comment, we show the results obtained by the IREA-CNR SAR team after processing the same ascending and descending CSK dataset, but by using two alternative and independent processing techniques: the Small BAseline Subset (SBAS) and the Advanced Tomographic SAR (TomoSAR) approaches, respectively. Our analysis shows that, although both the SBAS and the TomoSAR analyses allow achieving denser coherent pixel maps relevant to the Morandi bridge, nothing of the pre-collapse large displacements reported in Milillo et al. (2019) appears in our results, leading us to deeply disagree with the findings of their InSAR analysis.


2020 ◽  
Vol 12 (2) ◽  
pp. 299 ◽  
Author(s):  
Yanan Du ◽  
Guangcai Feng ◽  
Lin Liu ◽  
Haiqiang Fu ◽  
Xing Peng ◽  
...  

Coastal areas are usually densely populated, economically developed, ecologically dense, and subject to a phenomenon that is becoming increasingly serious, land subsidence. Land subsidence can accelerate the increase in relative sea level, lead to a series of potential hazards, and threaten the stability of the ecological environment and human lives. In this paper, we adopted two commonly used multi-temporal interferometric synthetic aperture radar (MTInSAR) techniques, Small baseline subset (SBAS) and Temporarily coherent point (TCP) InSAR, to monitor the land subsidence along the entire coastline of Guangdong Province. The long-wavelength L-band ALOS/PALSAR-1 dataset collected from 2007 to 2011 is used to generate the average deformation velocity and deformation time series. Linear subsidence rates over 150 mm/yr are observed in the Chaoshan Plain. The spatiotemporal characteristics are analyzed and then compared with land use and geology to infer potential causes of the land subsidence. The results show that (1) subsidence with notable rates (>20 mm/yr) mainly occurs in areas of aquaculture, followed by urban, agricultural, and forest areas, with percentages of 40.8%, 37.1%, 21.5%, and 0.6%, respectively; (2) subsidence is mainly concentrated in the compressible Holocene deposits, and clearly associated with the thickness of the deposits; and (3) groundwater exploitation for aquaculture and agricultural use outside city areas is probably the main cause of subsidence along these coastal areas.


2013 ◽  
Vol 347-350 ◽  
pp. 352-356
Author(s):  
Li Wang ◽  
Xi Min Cui ◽  
De Bao Yuan ◽  
Xue Qian Hong ◽  
Zai Jie Shi

For recent decades, especially with the launch of international commercial satellites carrying high-precision sensors, land use dynamic monitoring techniques based on high-resolution remote sensing imagery have undergone a phase of rapid development of key techniques applied in many aspects vastly. This paper is focused on the technological research and procedure of these key techniques, including the process of multi-temporal images, the information classification and feature extraction method, and also the analysis of classified result and driving factors influencing mutual conversion between land classes. Considering the representative meaning as its typicality in China, Yangzhou urban area was regarded as the study zone with multi-temporal images of three periods in the year of 1988, 2002 and 2007. During the procedure of classifying, object-oriented method was applied to e36xtract features from different multi-temporal imagery. Through comparative analysis, it was demonstrated that residential area expanded rapidly especially from 2002 to 2007 and area of the arable and other kinds of land cover reduced considerably. Finally, it is concluded that multiple driving forces affected the land use/change and multivariable linear regression model was used to explore the primary and secondary forces.


2006 ◽  
Vol 27 (8) ◽  
pp. 1709-1716 ◽  
Author(s):  
L. Cascini ◽  
S. Ferlisi ◽  
G. Fornaro ◽  
R. Lanari ◽  
D. Peduto ◽  
...  

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