Experimental investigation of salinity intrusion caused by a single tabular well

The rate of anthropogenic activities along with the coastal area has continuously increased throughout history. As a drawback, this change pushes the limits of the natural equilibrium in biota and surrounding wetlands. Likewise, coastal aquifers are among the primary water resources that are used to fulfil the local demands. This study investigates the changes of the interface between salt- and fresh-water in coastal area with the help of several laboratory-scale experiments. A sand box equipment with 1400 (length) × 400 (height) × 200 (width) × 10 (thickness) mm dimensions, made up of Plexiglass is used to imitate an unconfined aquifer near the coastline. A semi-uniform sand sample with 1~2 mm in diameter is used in the experiments, while the saltwater content (25 gr/lt) is dyed with 2 gr/lt food colouring to monitor the movement of the saltwater through the porous medium. A tabular well is also used to discharge the water either at 150 or 250 mm depths, that is located either at 250, 500, or 750 mm distant from the coastline. Then, the salt water movement through porous medium is monitored, to determine the vertical and horizontal velocity, acceleration, and permeability through the soil sample. Afterward, the obtained data is used to investigate the relationship between depth and location of the tabular well with the changes in the velocity, acceleration, and permeability of the salt water. It has been observed that the tabular well decreases the velocity of salt water movement in horizontal direction; while the velocity or acceleration through x-and y-axis changes with nonlinear nature. Hence, in the analysis of relationship between variables the selected nonlinear models could interpret about 70% of the observed disturbance in the ensemble of the scenarios.