Long-Term Land Subsidence Monitoring of Beijing (China) Using the Small Baseline Subset (SBAS) Technique

Abstract

Advanced techniques of multi-temporal InSAR (MT-InSAR) represent a valuable tool in ground subsidence studies allowing remote investigation of the behavior of mass movements in long time intervals by using large datasets of SAR images covering the same area and acquired at different epochs. The settlement in Beijing is very serious, producing adverse environmental impacts. Excessive groundwater withdrawal is the most direct cause of land subsidence.In this paper, a spatial-temporal analysis of the land subsidence in Beijing was performed using one of the MT-InSAR techniques, referred to as Small Baseline Subset (SBAS). This technique allows monitoring the temporal evolution of a deformation phenomenon, via the generation of mean deformation velocity maps and displacement time series from a data set of acquired SAR images. 52 C-band ENVISAT ASAR images acquired from June 2003 to August 2010 were used to produce a linear deformation rate map and to derive time series of ground deformation. The results show that there are three large subsidence funnels within this study area, which separately located in Balizhuang-Dajiaoting in Chaoyang district, Wangjing-Laiguangying Chaoyang district, Gaoliying Shunyi district. The maximum settlement center is Wangsiying-Tongzhou along the Beijing express; the subsidence velocity exceeds 110 mm/y in the LOS direction. In particular, we compared the achieved results with leveling measurements that are assumed as reference. The estimated long-term subsidence results obtained by SBAS approach agree OPEN ACCESS Remote Sens. 2014, 6 3649 well with the development of the over-exploitation of ground water, indicating that SBAS techniques is adequate for the retrieval of land subsidence in Beijing from multi-temporal SAR data.

Wuhan Surface Subsidence Analysis in 2015–2016 Based on Sentinel-1A Data by SBAS-InSAR

“…Location of study area and Sentinel-1A TOPS SAR data coverage: (a) the study area is outlined by a red rectangle; and (b) a SAR mean intensity image of Sentinel-1A covering the study area. [23,42].…”

Monitoring Mining Subsidence Using A Combination of Phase-Stacking and Offset-Tracking Methods

“…It has been used in many applications, such as the determination of the deformation caused by earthquakes [6,7], monitoring the surface subsidence caused by groundwater exploitation [8,9], detecting movement in volcanos [10,11], measuring the deformation resulting from landslides [12] and measuring mining-induced subsidence [13,14]. However, four problems have prevented the use of D-InSAR in monitoring land subsidence [15]: (1) spatial decorrelation caused by a long baseline between SAR image pairs; (2) time decorrelation resulting from a loss of coherence due to vegetation and changes in the land surface; (3) variations in signal delays caused by atmospheric delay; and (4) phase unwrapping errors [16].…”

Anatomy of Subsidence in Tianjin from Time Series InSAR

“…A radius of 1 km is usually assumed for volcano cases [51]. The maximum displacement for a finite sphere is about 1 + (α/d) 3 times of that for a point sphere [51]. Accordingly, the grid-like patterns appear when the ratio of cavity radius to depth is significant (Figure 9).…”

“…Subsidence caused by groundwater extraction is a worldwide problem [1][2][3]. Estimated subsidence rates range up to several hundred mm per year, highlighting the importance of continuous displacement mapping.…”