Impacts of hydrogeological characteristics on groundwater-level changes induced by earthquakes

Journal Article · Thu Mar 15 04:00:00 EDT 2018 · Hydrogeology Journal

DOI:https://doi.org/10.1007/S10040-017-1684-Z· OSTI ID:22780878

Liu, Ching-Yi; Chia, Yeeping; Chuang, Po-Yu ^[1]; Chiu, Yung-Chia ^[2]; Tseng, Tai-Lin ^[1]

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1. National Taiwan University, Department of Geosciences (China)
2. National Taiwan Ocean University, Institute of Applied Geosciences (China)

Changes in groundwater level during earthquakes have been reported worldwide. In this study, field observations of co-seismic groundwater-level changes in wells under different aquifer conditions and sampling intervals due to near-field earthquake events in Taiwan are presented. Sustained changes, usually observed immediately after earthquakes, are found in the confined aquifer. Oscillatory changes due to the dynamic strain triggered by passing earthquake waves can only be recorded by a high-frequency data logger. While co-seismic changes recover rapidly in an unconfined aquifer, they can sustain for months or longer in a confined aquifer. Three monitoring wells with long-term groundwater-level data were examined to understand the association of co-seismic changes with local hydrogeological conditions. The finite element software ABAQUS is used to simulate the pore-pressure changes induced by the displacements due to fault rupture. The calculated co-seismic change in pore pressure is related to the compressibility of the formation. The recovery rate of the change is rapid in the unconfined aquifer due to the hydrostatic condition at the water table, but slow in the confined aquifer due to the less permeable confining layer. Fracturing of the confining layer during earthquakes may enhance the dissipation of pore pressure and induce the discharge of the confined aquifer. The study results indicated that aquifer characteristics play an important role in determining groundwater-level changes during and after earthquakes.

• OSTI ID: 22780878
• Journal Information: Hydrogeology Journal, Journal Name: Hydrogeology Journal Journal Issue: 2 Vol. 26; ISSN 1431-2174
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
AQUIFERS
COMPRESSIBILITY
COMPUTER CODES
EARTHQUAKES
FINITE ELEMENT METHOD
GROUND WATER
HYDROSTATICS
MONITORING
PORE PRESSURE
SAMPLING
TAIWAN
WATER TABLES
WELLS