We evaluate the relative importance of the uncertainty related to parameters characterizing partially saturated groundwater flow on head and gravity changes associated with pumping tests taking place in homogeneous and heterogeneous porous media. We frame our study in a Global Sensitivity Analysis setting and assess the way imperfect knowledge of such parameters influences the probability distribution (pdf) of head and gravimetric variations recorded during well operation. We rely on a set of detailed computational analyses and conceptualize uncertain model parameters as random quantities. Randomly heterogeneous domains are treated by considering main geostatistical descriptors (i.e., variance and correlation scale) of three-dimensional spatial distributions of system properties as affected by uncertainty. We quantify the effects of the latter on the resulting pdf of (ensemble) mean and variance of head and gravity changes through a numerical Monte Carlo approach. While all uncertain parameters are influential to gravity changes in both homogeneous and randomly heterogeneous scenarios, consistent with the integral nature of gravity observations, our study enables us to quantify their relative importance. Values of Ensemble mean and variance of head and gravity changes associated with randomly heterogeneous fields are generally more influenced by the variance rather than by the correlation scale of the spatially heterogeneous parameters considered. Uncertainty in the correlation scale is more influential to the shape, and hence on extreme values, of the probability distribution of these moments.

我们评估了与表征部分饱和地下水流对水头和重力变化相关的参数的不确定性的相对重要性，这些变化与在均质和非均质多孔介质中进行的抽水试验相关。我们在全球敏感性分析设置中构建我们的研究，并评估这些参数的不完善知识影响井操作期间记录的水头和重力变化的概率分布 (pdf) 的方式。我们依靠一组详细的计算分析并将不确定的模型参数概念化为随机量。通过考虑受不确定性影响的系统特性的三维空间分布的主要地质统计描述符（即方差和相关尺度）来处理随机异质域。我们通过数值蒙特卡罗方法量化后者对（集合）均值和头部和重力变化方差的结果 pdf 的影响。虽然所有不确定参数都会影响均质和随机异质情景中的重力变化，但与重力观测的整体性质一致，我们的研究使我们能够量化它们的相对重要性。与随机异质场相关的整体均值和水头和重力变化的方差值通常更受方差而不是所考虑的空间异质参数的相关尺度的影响。相关尺度的不确定性对这些矩的概率分布的形状影响更大，因此对极值影响更大。