Research to date affirmed the key role of stream–aquifer interactions in integrated water resources management. The importance of river hydrodynamics on the spatial and temporal behaviour of groundwater was, however, not yet fully investigated. In contrast to the common approach where topography‐based estimates of riverbed elevation may lead to inappropriate discretization and constant river stages, this study couples a fully hydrodynamic and one‐dimensional river model to a two‐dimensional catchment hydrological model. The surface and subsurface runoff, groundwater, and river components are integrated into a single modelling framework. The coupled model was applied to a medium sized catchment in Belgium with three model setups, in which the level of detail of representation of river hydrodynamics varies. Further model iterations were carried out for the most exhaustive setup to assess the importance of the bi‐directional interactions between model components. Results show that higher details of river hydrodynamics help to improve the simulation of time‐averaged groundwater levels. However, the impacts were not that clear for the time‐varying groundwater levels. Moreover, visual and statistical model performance evaluation indicates a strong enhancement of the coupled models compared to the output from the hydrological model with respect to river discharge observations at catchment outlet and at internal stations. It also reveals the impact of river hydrodynamics on groundwater discharges when the most detailed setting delivered the highest performance among the three coupled models.

中文翻译：

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论河流水动力在模拟地下水位和基流中的重要性

迄今为止的研究证实了流水层相互作用在综合水资源管理中的关键作用。然而，尚未充分研究河流水动力对地下水的时空行为的重要性。与基于地形的河床高程估计可能导致不适当的离散化和恒定河段的通用方法相反，本研究将完全水动力和一维河模型与二维集水区水文模型相结合。地表和地下径流，地下水和河流成分被集成到单个建模框架中。耦合模型通过三种模型设置应用于比利时的一个中型流域，其中河流水动力表示的详细程度有所不同。为了最详尽的设置，还进行了进一步的模型迭代，以评估模型组件之间双向交互的重要性。结果表明，河流水动力学的更多细节有助于改进时均地下水位的模拟。但是，对于随时间变化的地下水位影响尚不明确。此外，就流域出口处和内部站的河流排放观测而言，视觉和统计模型的性能评估表明，与水文模型的输出相比，耦合模型有了很大的增强。当三个耦合模型中最详细的设置提供了最高的性能时，它还揭示了河流水动力对地下水排放的影响。