Groundwater flow systems are strongly influenced by heterogeneity and anisotropy of hydraulic conductivity (K). Particularly in stratified clastic sedimentary aquifers, the vertical hydraulic gradient (dh/dz) is often very high, due to the low vertical hydraulic conductivity (K_v) or high anisotropy (K_h/K_v). However, data on the vertical hydraulic gradient to calibrate the anisotropy is seldom available. We investigated the relationship between the variable K_h/K_v and the dh/dz computed by a groundwater flow model to improve the regional parameterization using an extensive data base on 3D distribution of hydraulic head. Although it is commonly assumed that the value of K_h/K_v is 10, our values typically ranged between 10 and 10⁵, because the maximum K_h/K_v was 10⁵ in this regional basin. The simulations used MODFLOW-2000. We found that the high K_h/K_v contributed to high dh/dz, while identifying locations of potentially good vertical connectivity between the aquifer zones, where dh/dz is very low and difficult to measure sufficiently accurately. Sensitivity analysis of dh/dz to recharge and pumping from wells showed that recharge led to change in inflow of groundwater that led to head change, which in turn led to change in dh/dz. While, pumping contributed to aquifer outflow, as change in head drawdown around the influence zone, in turn changed dh/dz. Additionally, dh/dz in a shallower aquifer was more strongly affected by recharge and pumping.

地下水流动系统受水力传导率（K）的非均质性和各向异性的强烈影响。特别是在分层碎屑沉积含水层中，由于垂直水力传导率低（K _v）或各向异性高（K _h / K _v）高，垂直水力梯度（dh / dz）通常很高。但是，很少有用于校准各向异性的垂直水力梯度的数据。我们研究了变量K _h / K _v与dh / dz之间的关系使用广泛的基于液压头的3D分布数据库，通过地下水流模型计算出的水，以改善区域参数化。尽管通常假设K _h / K _v的值为10，但我们的值通常在10到10 ⁵之间，因为该区域盆地的最大K _h / K _v为10 ⁵。仿真使用的是MODFLOW-2000。我们发现，较高的K _h / K _v导致较高的dh / dz，同时确定了dh / dz含水层区域之间潜在的良好垂直连通性的位置。极低，很难准确测量。dh / dz对井中补给和抽水的敏感性分析表明，补给导致地下水流入量的变化，从而导致水头变化，进而导致dh / dz的变化。同时，抽水导致含水层流出，因为影响区周围水头下降的变化反过来改变了dh / dz。此外，浅水层中的dh / dz受补给和抽水的影响更大。