Geomechanics of subsurface water withdrawal and injection
G. Gambolati, P. Teatini
Dept. of Civil, Architectural and Environmental Engineering, University of Padova, Padova, Italy
Land subsidence and uplift, ground ruptures, and induced seismicity are the principal geomechanic
effects of groundwater withdrawal and injection. The major environmental consequence of groundwater pumping
is anthropogenic land subsidence. The first observation concerning land settlement linked to subsurface
processes was made in 1926 by the American geologists Pratt and Johnson, who wrote that ‘‘the cause of subsidence
is to be found in the extensive extraction of fluid from beneath the affected area.’’ Since then, impressive
progress has been made in terms of: (a) recognizing the basic hydrologic and geomechanic principles underlying
the occurrence; (b) measuring aquifer compaction and ground displacements, both vertical and horizontal;
(c) modeling and predicting the past and future event; and (d) mitigating environmental impact through aquifer
recharge and/or surface water injection. The first milestone in the theory of pumped aquifer consolidation was
reached in 1923 by Terzaghi, who introduced the principle of ‘‘effective intergranular stress.’’ In the early 1970s,
the emerging computer technology facilitated development of the first mathematical model of the subsidence
of Venice, made by Gambolati and Freeze. Since then, the comprehension, measuring, and simulation of the
occurrence have improved dramatically. More challenging today are the issues of ground ruptures and induced/
triggered seismicity, which call for a shift from the classical continuum approach to discontinuous mechanics.
Although well known for decades, anthropogenic land subsidence is still threatening large urban centers and
deltaic areas worldwide, such as Bangkok, Jakarta, and Mexico City, at rates in the order of 10 cm/yr.
