Linear poroelasticity of groundwater levels from observational records at wells in Hokkaido, Japan
Linear poroelasticity of groundwater levels from observational records at wells in Hokkaido, Japan
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DOI：
10.1016/j.tecto.2009.10.025
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发表时间：
2010-03
期刊：
影响因子：
2.9
通讯作者：
T. Shibata;N. Matsumoto;F. Akita;N. Okazaki;H. Takahashi;R. Ikeda
中科院分区：
文献类型：
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作者：
T. Shibata;N. Matsumoto;F. Akita;N. Okazaki;H. Takahashi;R. Ikeda
地下水位的自然波动不仅取决于施加到含水层上的应力，而且取决于组成含水层的岩石的类型。孔隙弹性参数，如应变敏感性、加载效率和孔隙弹性体积模量，被用来分析含水层的水文属性。在这项研究中，我们使用记录的地下水位从19个威尔斯计算系数的孔隙弹性特征。这些记录可以全面描述地下水位如何随着地壳内部体积应变的波动而变化。我们用两种方法估计应变敏感性：（a）利用威尔斯井对潮汐应变的响应和（B）利用基于历史数据的地下水位同震变化。两种方法估算的应变灵敏度具有良好的线性相关性。我们还估计加载效率使用观测记录和计算体积模量的加载效率和应变灵敏度。以这种方式获得的体积模量与实验室值大致一致。
The natural fluctuation of groundwater level depends not only on the stress applied to an aquifer but also on the type of rock that comprises it. Poroelastic parameters, such as strain sensitivity, loading efficiency, and poroelastic bulk moduli, are used to analyze the hydrologic attributes of aquifers. In this study, we use records of groundwater levels from 19 wells to calculate coefficients of poroelastic characteristics. The records allow a comprehensive description of how groundwater levels vary with fluctuations of volumetric strain in the crust's interior. We estimate strain sensitivities in two ways: (a) using the wells' response to tidal strain and (b) using coseismic changes in groundwater level based on historical data. The strain sensitivities estimated by the two different methods have good linear correlation. We also estimate loading efficiency using observational records and calculate bulk moduli from the loading efficiencies and strain sensitivities. The bulk moduli obtained in this manner are roughly consistent with laboratory values.