Abstract The interaction between surface water and groundwater through the hyporheic zone is recognized to be important as it impacts the water quantity and quality in both flow systems. Three-dimensional (3D) modeling is the most complete representation of a real-world hyporheic zone. However, 3D modeling requires extreme computational power and efforts; the sophistication is often significantly compromised by not being able to obtain the required input data accurately. Simplifications are therefore often needed. The objective of this study was to assess the accuracy of the vertically-averaged approximation compared to a more complete vertically-resolved model of the hyporheic zone. The groundwater flow was modeled by either a simple one-dimensional (1D) Dupuit approach or a two-dimensional (2D) horizontal/vertical model in boundary fitted coordinates, with the latter considered as a reference model. Both groundwater models were coupled with a 1D surface water model via the surface water depth. Applying the two models to an idealized pool-riffle sequence showed that the 1D Dupuit approximation gave comparable results in determining the characteristics of the hyporheic zone to the reference model when the stratum thickness is not very large compared to the surface water depth. Conditions under which the 1D model can provide reliable estimate of the seepage discharge, upwelling/downwelling discharges and locations, the hyporheic flow, and the residence time were determined.

中文翻译：

---

水池浅滩底形下潜流流的垂直平均模型和垂直解析模型的比较

摘要 通过潜流带的地表水和地下水之间的相互作用被认为是重要的，因为它影响两个流动系统中的水量和水质。三维 (3D) 建模是真实世界低流带的最完整表示。然而，3D 建模需要极高的计算能力和工作量；由于无法准确获取所需的输入数据，复杂性通常会受到严重影响。因此经常需要简化。本研究的目的是评估垂直平均近似与更完整的低流带垂直分辨率模型相比的准确性。地下水流通过简单的一维 (1D) Dupuit 方法或边界拟合坐标中的二维 (2D) 水平/垂直模型进行建模，后者被视为参考模型。两种地下水模型都通过地表水深度与一维地表水模型相结合。将这两个模型应用于理想化的水池浅滩序列表明，当地层厚度与地表水深度相比不是很大时，1D Dupuit 近似在确定下流带的特征时给出了与参考模型相当的结果。确定了 1D 模型可以提供渗流排放、上流/下流排放和位置、下流流和停留时间的可靠估计的条件。两种地下水模型都通过地表水深度与一维地表水模型相结合。将这两个模型应用于理想化的水池浅滩序列表明，当地层厚度与地表水深度相比不是很大时，1D Dupuit 近似在确定下流带的特征时给出了与参考模型相当的结果。确定了 1D 模型可以提供渗流排放、上流/下流排放和位置、下流流和停留时间的可靠估计的条件。两种地下水模型都通过地表水深度与一维地表水模型相结合。将这两个模型应用于理想化的水池浅滩序列表明，当地层厚度与地表水深度相比不是很大时，1D Dupuit 近似在确定下流带的特征时给出了与参考模型相当的结果。确定了 1D 模型可以提供渗流排放、上流/下流排放和位置、下流流和停留时间的可靠估计的条件。将这两个模型应用于理想化的水池浅滩序列表明，当地层厚度与地表水深度相比不是很大时，1D Dupuit 近似在确定下流带的特征时给出了与参考模型相当的结果。确定了 1D 模型可以提供渗流排放、上流/下流排放和位置、下流流和停留时间的可靠估计的条件。将这两个模型应用于理想化的水池浅滩序列表明，当地层厚度与地表水深度相比不是很大时，1D Dupuit 近似在确定下流带的特征时给出了与参考模型相当的结果。确定了 1D 模型可以提供渗流排放、上流/下流排放和位置、下流流和停留时间的可靠估计的条件。