Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

Environmental and Engineering Geoscience

This Article Figures Only Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by SHENG, Z. Articles by LI, J. Search for Related Content GeoRef GeoRef Citation

Mechanisms of Earth Fissuring Caused by Groundwater Withdrawal

¹ Texas A&M University System, El Paso Agricultural Research and Extension Center,1380 A&M Circle, El Paso, TX 79927
² Department of Civil Engineering, Morgan State University, 5200 Perring Parkway, Baltimore, MD 21251

Earth fissures associated with groundwater withdrawal are complex products of both human activities and natural forces, and they occur in definable geological environments. In this paper, the authors first characterize the driving forces for earth fissures caused by groundwater withdrawal. Then, the effects of various factors, such as stresses and pre-existing geological structures, are examined using conceptual models. Numerical results show that the fissuring process is controlled not only by the induced movement at depth and pre-existing structures but also by the in situ stress field. In addition, the degree to which aquifer movement and pre-existing structures actually trigger fissuring depends greatly on the in situ stress field. The authors conclude that earth fissuring related to groundwater withdrawal is a multi-step process that is influenced by a multiplicity of factors, one being the aquifer movement. With groundwater withdrawal, hydraulic and gravitational forces tend to drive aquifer material to deform both horizontally and vertically. Cumulative deformation or strain results in movement. In turn, this aquifer movement results in differential displacements at depth along planes of weakness, such as pre-existing faults and material interfaces. This differential movement (both horizontal and vertical) then generates tensile zones at depth. Once formed, such a tensile zone may migrate upward, form a crack (fail) where the vadose zone is brittle, and eventually express itself as an earth fissure at the land surface in arid or semi-arid regions. In humid regions, the same tensile zone (lateral stretching) at depth will simply express itself as a transient sub-vertical plane of enhanced porosity within and crossing the vadose zone.

Key Words: Aquifer Movement • Boundary Element Method • Driving Forces • Earth Fissures • Groundwater Withdrawal • In Situ Stresses • Land Subsidence • Soil Masses