Waterloo Institute for Groundwater Research, Department of Earth & Environmental Sciences, University of Waterloo, Waterloo, Canada N2L 3G1.
Ground Water. 2011 Nov-Dec;49(6):815-29. doi: 10.1111/j.1745-6584.2010.00781.x. Epub 2011 Jan 4.
For almost 80 years, deformation-induced head changes caused by poroelastic effects have been observed during pumping tests in multilayered aquifer-aquitard systems. As water in the aquifer is released from compressive storage during pumping, the aquifer is deformed both in the horizontal and vertical directions. This deformation in the pumped aquifer causes deformation in the adjacent layers, resulting in changes in pore pressure that may produce drawdown curves that differ significantly from those predicted by traditional groundwater theory. Although these deformation-induced head changes have been analyzed in several studies by poroelasticity theory, there are at present no practical guidelines for the interpretation of pumping test data influenced by these effects. To investigate the impact that poroelastic effects during pumping tests have on the estimation of hydraulic parameters, we generate synthetic data for three different aquifer-aquitard settings using a poroelasticity model, and then analyze the synthetic data using type curves and parameter estimation techniques, both of which are based on traditional groundwater theory and do not account for poroelastic effects. Results show that even when poroelastic effects result in significant deformation-induced head changes, it is possible to obtain reasonable estimates of hydraulic parameters using methods based on traditional groundwater theory, as long as pumping is sufficiently long so that deformation-induced effects have largely dissipated.
近 80 年来，在多层含水层-隔水层系统的抽水试验中，一直观察到由于孔隙弹性效应引起的变形导致的水头变化。当含水层中的水在抽水过程中从压缩储存中释放出来时，含水层会在水平和垂直方向上发生变形。受抽水区变形的影响，相邻层也会发生变形，从而导致孔隙压力发生变化，这可能会产生与传统地下水理论预测的明显不同的降落曲线。尽管已有几项研究运用孔隙弹性理论对这些变形引起的水头变化进行了分析，但目前还没有针对受这些影响的抽水试验数据解释的实用指南。为了研究抽水试验过程中的孔隙弹性效应对水力参数估计的影响，我们使用孔隙弹性模型为三种不同的含水层-隔水层设置生成了合成数据，然后使用基于传统地下水理论且不考虑孔隙弹性效应的标准曲线和参数估计技术来分析这些合成数据。结果表明，即使孔隙弹性效应导致显著的变形引起的水头变化，只要抽水时间足够长，以使变形引起的效应基本消散，那么仍然可以使用基于传统地下水理论的方法来获得合理的水力参数估计值。
