Experimental Research on Effect of Tide for Coastal Groundwater Table

Abstract

A tide simulation system based on two‐way water pump technique is developed by authors. Using this system, the groundwater table fluctuation characteristics, relative over height of groundwater table, and influencing factors of over height are investigated. The experiment results indicate that the groundwater table fluctuation is of periodicity, and of asymmetry. The amplitude of groundwater table fluctuations decreases with the increase of the onshore distances. There are phase lags of groundwater table fluctuations for different monitoring points. The tide can cause remarkable over height of coastal groundwater table. The dominating factors bring about over height include tide amplitude, tide frequency and aquifer thickness. Under above experiment conditions, the maximum value of over height exceeded 50% of the maximal tide amplitude, and reached about 10% of aquifer thickness. So, over height is not a negligent factor of forecasting the groundwater resource gross in coastal area.