Monitoring of Land Subsidence and Ground Fissure Activity within the Su-Xi-Chang Area Based on Time-Series InSAR

Abstract

Serious land subsidence and ground fissure (GF) disasters have brought huge economic losses to the Su-Xi-Chang area (China) and threatened the safety of its residents. To better understand the development of these disasters, it is urgent to carry out long-term and large-scale deformation monitoring in this region. In this study, based on time-series interferometric synthetic aperture radar (InSAR) technology, ground deformation characteristics were obtained at different periods. Meanwhile, Fast Lagrangian Analysis of Continua in Three Dimensions (FLAC3D) was used to study the stress, seepage field, and displacement changes in the soil layers caused by pumping activities at the bedrock bulge. The results showed that three subsidence centers were located in Suzhou, Wuxi, and Changzhou from 2007 to 2010. The ground fissures in Guangming village had obvious differential settlements and intense activities. The land subsidence in the Su-Xi-Chang area was under control from 2018 to 2021, while there was a relative rebound in most areas. Combined with numerical simulation and geological data, we demonstrated that pumping activities would accelerate and intensify the land subsidence process, and differential subsidence was prone to occur at the buried hill, which in turn led to the formation of ground fissures. By comparing the characteristics of ground deformation in different periods, it was proven that banning groundwater exploitation is an effective measure for preventing and controlling such disasters.

Quantitative Assessment and Impact Analysis of Land Surface Deformation in Wuxi Based on PS-InSAR and GARCH Model

“…Although previous studies [44] used different data and methods to monitor surface deformation, they were able to identify similar subsidence/uplift areas and surface deformation rates. Compared with the research results of previous studies, the spatiotemporal distribution characteristics of the subsidence areas detected in this paper are basically consistent with the research results of previous studies [28].…”

“…As shown in Figure 13, the stratigraphic structure of Wuxi is quite complex, with sub-clay, silt, clay in the upper part, sub-clay and sub-sandy soil in the lower part, which together form the soft soil layer of the Wuxi area. During the Quaternary sedimentation process, affected by sea-land alternation, changes in the Yangtze River water level, and river course changes, the lithology of the region is complex, characterized by multi-layered cohesive soil layers and alternating loose sand layers, which is the direct reason for the interlayering of sub-clay and silt [28]. Additionally, the stratigraphic changes in Wuxi are highly uneven in the horizontal direction.…”

“…In recent years, numerous scholars have investigated this region. Yang et al, for instance, employed PS-InSAR technology and three-dimensional continuous medium simulation to analyze ground subsidence and ground fissure activities in the Su-Xi-Chang area of China, confirming that prohibiting groundwater extraction is an effective measure to prevent and control these disasters [28]. Similarly, Wang et al utilized SBAS-InSAR technology to monitor ground subsidence in Wuxi City from 2007 to 2011, concluding that the subsidence might be related to large-scale land consolidation projects [29].…”

A New Method for Continuous Track Monitoring in Regions of Differential Land Subsidence Rate Using the Integration of PS-InSAR and SBAS-InSAR

“…These regions have various types of groundwater, an uneven distribution of groundwater, and complex burial conditions, with distinctive regional characteristics. It was found that the Suzhou-Wuxi-Changzhou area has suffered severe land subsidence due to long-term excessive exploitation, ground fissure activity and pumping [55,56]. Based on long-term measurement data, the uneven land subsidence and the differential settlement of infrastructure in Shanghai were caused by groundwater exploitation and artificial recharge in an alternated multi-aquifer-aquitard system [57].…”

Ground Deformation in Yuxi Basin Based on Atmosphere-Corrected Time-Series InSAR Integrated with the Latest Meteorological Reanalysis Data

“…Ground subsidence is a geological phenomenon caused by natural or human-induced consolidation and compression of loose underground rock layers, resulting in a decrease in the ground elevation within a certain area [1,2]. Ground subsidence is a slow-deformation geological hazard with uneven and irreversible characteristics [3,4]. Many areas of the world are affected by severe ground subsidence, such as central Mexico, Las Vegas, USA, and Jakarta, Indonesia [5][6][7].…”