Coastal fresh groundwaters face growing threats from rising withdrawals and climate change, with salinization of surface and groundwater as notable impacts. Recent developments in parallel variable-density modelling enable studying these threats at unexplored resolutions and extents. To improve the understanding of ground- and surface water salinization processes, we designed an experiment to measure how spatial resolution affects both groundwater salinity distribution and salt loads to surface waters. An existing parallelized coupled variable-density groundwater flow and salt transport (VD-GWT) model is applied to a region in the Netherlands whereby the surface water drainage network is parameterized at grid resolutions between 10 and 250 m. The results show a strong dependency between resolution and the salinity distribution in shallow groundwater while simulated salt loads are affected by imperfect flux scaling. The computational resources needed for this test suggest that regional high-resolution VD-GWT models are feasible using HPC environments, albeit not practical.

中文翻译：

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网格分辨率对区域模拟地下水盐度和地表水盐通量的影响


沿海淡水地下水面临日益严重的威胁，来自不断增长的取水量和气候变化，其中地表水和地下水的盐碱化是显著影响。并行可变密度建模的最新发展使得在未探索的分辨率和范围下研究这些威胁成为可能。为了提高对地下水和地表水盐碱化过程的理解，我们设计了一个实验来测量空间分辨率如何影响地下水盐度分布和地表水的盐负荷。现有的并行耦合可变密度地下水流和盐输送 （VD-GWT） 模型应用于荷兰的一个地区，其中地表水排水网络以 10 到 250 m 之间的网格分辨率进行参数化。结果表明，分辨率与浅层地下水中的盐度分布之间存在很强的依赖性，而模拟的盐负荷会受到不完美通量缩放的影响。该测试所需的计算资源表明，使用 HPC 环境的区域高分辨率 VD-GWT 模型是可行的，尽管不实用。