A preliminary study of the changes in groundwater levels affected by tide in coastal aquifers

• 1、China University of Geosciences
• 2、Beihai Institute of Hydrogeology, Engineering Geology and Mineral Resources in Guangxi
• 3、School of Water Resources and Environment, China University of Geosciences

Abstract：Based on short and long series of observations of tide and groundwater levels, changes in groundwater levels affected by the tide in coastal aquifers in Beihai are analyzed in this paper. The results indicate that groundwater levels under the tidal effect fluctuate as the tide oscillates and the amplitude of the groundwater levels is less than that of the tide. The amplitude of the groundwater levels or the tidal coefficients decrease with the distance far from the coast and can roughly be described using a negative exponential function. Groundwater levels are thought not to be affected by the tide when the distances from the coast in the southern and northern coasts are 3756 and 2266 m, respectively. The observation data of the long series also show that the tide and the groundwater levels near the coast fluctuate with a long period of about 15 days and a short period of about 1 day.

Keywords： Tidal effect period groundwater regime coastal aquifer Beihai