SPEA 439, Indiana University, Bloomington, IN 47405, USA.
Ground Water. 2010 Nov-Dec;48(6):878-83. doi: 10.1111/j.1745-6584.2010.00694.x.
Horizontal wells or radial collector wells are used in shallow aquifers to enhance water withdrawal rates. Groundwater flow patterns near these wells are three-dimensional (3D), but difficult to represent in a 3D numerical model because of the high degree of grid refinement needed. However, for the purpose of designing water withdrawal systems, it is sufficient to obtain the correct production rate of these wells for a given drawdown. We developed a Cauchy boundary condition along a horizontal well in a Dupuit-Forchheimer model. Such a steady-state 2D model is not only useful for predicting groundwater withdrawal rates but also for capture zone delineation in the context of source water protection. A comparison of our Dupuit-Forchheimer model for a radial collector well with a 3D model yields a nearly exact production rate. Particular attention is given to horizontal wells that extend underneath a river. A comparison of our approach with a 3D solution for this case yields satisfactory results, at least for moderate-to-large river bottom resistances.
水平井或径向集水井用于浅层含水层以提高取水量。这些井附近的地下水流动模式是三维的，但由于需要高度的网格细化，很难在三维数值模型中表示。然而，对于设计取水系统而言，获得给定降深下这些井的正确出水量就足够了。我们在Dupuit-Forchheimer 模型中沿着水平井开发了柯西边界条件。这种稳定的二维模型不仅有助于预测地下水取水量，而且有助于在水源保护的背景下划定集水区。将我们的径向集水井 Dupuit-Forchheimer 模型与 3D 模型进行比较，得出了几乎完全相同的出水量。特别关注延伸到河流下方的水平井。将我们的方法与这种情况下的 3D 解决方案进行比较，结果令人满意，至少对于中等至大的河床阻力而言是如此。
