Land subsidence and earth fissures due to groundwater withdrawal in the Southern Yangtse Delta, China

• Published in: Environmental geology (Berlin) 2008-08, Vol.55 (4), p.751-762
• Main Authors: Zhang, Yun, Xue, Yu-Qun, Wu, Ji-Chun, Yu, Jun, Wei, Zi-Xin, Li, Qin-Fen
• Format: Article
• Language: English
• Subjects: Aquifer system compaction; Brackish; Earth and Environmental Science; Earth fissure; Earth Sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Freshwater; Geology; Groundwater extraction; Hydrogeology; Hydrology. Hydrogeology; Land subsidence; Marine; Natural hazards: prediction, damages, etc; Original Article; Pollution, environment geology; The Southern Yangtse Delta
• ISSN: 0943-0105; 1432-0495
• DOI: 10.1007/s00254-007-1028-8

Excessive extraction of groundwater has caused severe land subsidence and earth fissures in the Southern Yangtse Delta, China. Based on field data, the temporal and spatial distribution of land subsidence is investigated and the causes for earth fissures are analyzed. The areal distribution of the land subsidence is closely related to the cones of depression in the main exploited aquifers. The compaction of a hydrostratigraphic unit depends on its mechanical behavior, thickness, compressibility, and the piezometric level changing. The primary subsidence layers in Shanghai have been the first aquitard before 1990 and the third confined aquifer since then. But the second aquitard unit was the primary subsidence layer in Changzhou. Earth fissures, trending in several directions, occurred in the Husu tectonic zone. They were mainly caused by differential subsidence and horizontal displacement that resulted from tensile stress and shear stress in units. The majority of fissures in the study area are tensile.