Studies of solute transport in unconfined coastal aquifers typically neglect oceanic oscillations and assume a static seaward boundary condition defined by the mean annual sea level. In this paper, an image monitoring method is used to establish the quantitative relationship between the concentration of a colored tracer and the hue value of the image. The digital image was used to determine the tracer concentration distribution. Controlled laboratory experiments were conducted to quantitatively study the relationship between the tidal amplitude and the solute transport time and dispersion. Experiments show that the solute transport time is not associated with the tidal amplitude, but only with the average hydraulic gradient between the seaward boundary and the landward boundary. The dispersion range of the solute plume increases with the increase of the tidal amplitude. On large-scale beaches in nature, when the average hydraulic gradient of the aquifer between the sea side and the land side is small enough, the dispersion coefficient is proportional to the tidal amplitude in equal proportion. Therefore, when it comes to the transport time of pollutants, it is possible to set the seaward boundary as the mean annual sea level. In a study of the dispersion range of pollutants, it is inappropriate to set the seaward boundary as the mean annual sea level.

非承压沿海含水层中的溶质迁移研究通常忽略海洋振荡，并假设由年平均海平面定义的静态向海边界条件。本文采用图像监测方法，建立了有色示踪剂浓度与图像色相值之间的定量关系。数字图像用于确定示踪剂浓度分布。进行了受控的实验室实验，以定量研究潮汐幅度与溶质迁移时间和分散度之间的关系。实验表明，溶质运移时间与潮位无关，只与向海边界和向陆边界的平均水力梯度有关。溶质羽流的弥散范围随着潮幅的增大而增大。在自然界的大尺度海滩上，当海侧和陆侧之间含水层的平均水力梯度足够小时，离散系数与潮幅等比例成正比。因此，在污染物的迁移时间上，可以将向海边界设为年平均海平面。在研究污染物扩散范围时，不宜将向海边界设定为年平均海平面。在污染物的迁移时间上，可以将向海边界设定为年平均海平面。在研究污染物扩散范围时，不宜将向海边界设定为年平均海平面。在污染物的迁移时间上，可以将向海边界设定为年平均海平面。在研究污染物扩散范围时，不宜将向海边界设定为年平均海平面。