Abstract Two-dimensional sandbox experiments were conducted to investigate the variable-density circulation and flow patterns in sloping beach configurations. The experiments provide new benchmark results for validating the sandbox models based on quantitative and qualitative measurements. Previous studies have considered density dependent flow in porous media, vertical beach face saltwater boundary, and multilayered hydrogeology ignoring a sloping beach face, which is a much more common phenomenon in real world. The present study considers sloping beach face under both homogeneous and low-permeability strata configurations. The geohydraulic processes encountered were quantified through pore-water pressure measurements and image analysis techniques. Moreover, validations were performed with numerical simulations (FEFLOW). A simple image analysis procedure is proposed with respect to two-dimensional laboratory scale benchmark experiments. Experimental results provided a detailed circulation flow path within and outside the saltwater wedge with sloping beach face. Fingering effect in porous media was also observed for both the experiments during initial time periods. Stability analysis shows the existence of a stationary convective flow pattern followed by gravitational instabilities under a the quasi-steady state condition.

中文翻译：

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静态滨海边界条件下倾斜沙滩海水入侵动力学实验与数值研究

摘要 进行了二维沙箱实验以研究倾斜海滩配置中的变密度环流和流动模式。实验为基于定量和定性测量验证沙箱模型提供了新的基准结果。先前的研究已经考虑了多孔介质中的密度相关流动、垂直海滩面咸水边界和忽略倾斜海滩面的多层水文地质学，这在现实世界中是一种更为普遍的现象。本研究考虑了均质和低渗透地层构造下的倾斜海滩面。遇到的地质液压过程通过孔隙水压力测量和图像分析技术进行量化。此外，还通过数值模拟 (FEFLOW) 进行了验证。针对二维实验室规模基准实验提出了一种简单的图像分析程序。实验结果提供了具有倾斜海滩面的咸水楔内部和外部的详细循环流动路径。在初始时间段的两个实验中也观察到了多孔介质中的指法效应。稳定性分析表明，在准稳态条件下，存在稳定的对流流动模式，随后是重力不稳定性。