Mechanisms for earth fissure formation due to groundwater extraction in the Su-Xi-Chang area, China

Abstract

Excessive groundwater withdrawal has caused many earth fissures in the cities of Suzhou, Wuxi, and Changzhou (i.e., the Su-Xi-Chang area or ''SXC area'') in Jiangsu Province, China. The appearance of these fissures is closely associated with groundwater withdrawal both temporally and spatially. Based on field investigations, three models of the earth fissures in the SXC area were conceptualized. The changes in and distributions of normal and shear stress in hydrostratigraphic units due to groundwater extraction were analyzed numerically for each conceptualized model. Results from these numerical simulations indicated that geological conditions play a crucial role in the occurrence and distribution of earth fissures. Earth fissures are much more likely to initiate in areas where the depth of the bedrock below the ground surface is small, the thickness of the exploited aquifer unit changes abruptly, and the surface of the bedrock undulates dramatically. Earth fissures are also likely to occur in the vicinity of a distant restricted boundary. In addition, very stiff topsoil is more prone to cracking, and the locations of discharge wells also influence the occurrence of earth fissures.

A Novel Approach to Model Earth Fissure Caused by Extensive Aquifer Exploitation and its Application to the Wuxi Case, China

“…According with the modeling results, earth fissuring began in the early 1990s and, consistently with the observations, developed mainly from the late 1990s to the mid‐2000s. The fissure become inactive after 2006, inconsistently with the more recent records; Figure b shows that the earth fissure crossed Guangming for a length of approximately 100 m. The model provides a fissure about 1 order of magnitude longer than these local observations (Figures and ); Consistently with the available measurements (Ye et al, ; Zhang et al, ), opening and sliding of this earth fissure has been quantified in the order of a tens of centimeters (Figure ). However, direct observations at Guangming (Figure c) reported that sliding seems to prevail on opening, which is the opposite of what computed by the model.…”

A Parametric Numerical Analysis of Factors Controlling Ground Ruptures Caused by Groundwater Pumping

“…Ground rupture, with fracture opening (Earth fissure; Figure a) or small to large vertical offset (faulting; Figure b), is a geomechanical process that may be associated with groundwater pumping from unconsolidated sedimentary aquifer systems. Apart from a few occurrences, for example those in Suzhou‐Wuxi‐Changzhou area, Yangtze River delta, China (Ye et al, ; Zhang et al, ), ground ruptures associated with groundwater pumping generally develop in arid or semiarid basins. The largest densities of ground ruptures are located in Arizona, USA (Conway, ; Jachens & Holzer, ), central Mexico (Carreón‐Freyre, ; Carreón‐Freyre et al, ; Teatini et al, ), northern China (Li et al, ; Peng et al, ), and Iran (Ziaie et al, ), where the average annual precipitation is 200, 500, 550, and 300 mm, respectively.…”

Deformation Monitoring of Earth Fissure Hazards Using Terrestrial Laser Scanning

“…The fold systems become the basement, with undulating surfaces overlaid by sediment. Anticline covered by quaternary sedimentary layers is the so-called buried hill [21,22]. The presence of the buried hill greatly impacts the geological and hydro-geological structure models.…”