Contamination of groundwater in coastal aquifers is a significant environmental concern for coastal populations across the world. As it not only leads to the depletion of available freshwater resources, but also threatens the ecology and economy of the coastal zones. A quantitative understanding of contaminant transport processes within coastal aquifer systems is, therefore, essential for efficient planning and management of coastal environments. The overarching aim of this research is to investigate the behaviour of contaminant transport patterns for various contaminant transport scenarios in a coastal unconfined aquifer. For this purpose, a series of laboratory-scale experiments have been carried out in the setup of a rectangular flow tank using dye to trace the movement of contaminant plume patterns with homogeneous soil formations. The experimental data indicate that the contaminant travels upward towards the seaward boundary when it approaches the saltwater wedge and then exits around the coastline. Upon installation of the pump, the saltwater intrusion wedge was moving rapidly towards the freshwater aquifer, and the contaminant was also moving along with the saltwater wedge towards the pump location. Experimental results also clearly show that the contaminant plume formed an elongated shape as it approached the saltwater–freshwater interface due to dispersion effects. The findings from this experimental study helped us to have a better understanding of the contaminant transport processes occurring in a coastal unconfined aquifer.

沿海含水层中的地下水污染是世界各地沿海人口关注的重大环境问题。因为它不仅导致可用淡水资源的枯竭，而且还威胁着沿海地区的生态和经济。因此，对沿海含水层系统内污染物传输过程的定量了解对于有效规划和管理沿海环境至关重要。这项研究的总体目标是研究沿海无限制含水层中各种污染物传输情景下污染物传输模式的行为。为此，在矩形流槽的设置中进行了一系列实验室规模的实验，使用染料来跟踪具有均匀土壤形成的污染物羽流模式的运动。实验数据表明，当污染物接近咸水楔形物时，它会向上向海边界移动，然后在海岸线附近散出。安装泵后，盐水入侵楔块迅速向淡水含水层移动，污染物也随盐水楔块一起向泵位置移动。实验结果还清楚地表明，由于扩散作用，污染物羽流接近盐水-淡水界面时形成细长的形状。这项实验研究的发现帮助我们更好地了解了沿海无限制含水层中污染物的迁移过程。