Tidal effects on groundwater level in coastal region under human disturbance

摘要

Seawater intrusion has become a worldwide environmental alarming problem with global warming and sea level changes. A series of achievements have been made during last several decades, but the role of tidal effect in seawater intrusion has not yet been revealed, especially under the human disturbance. In this paper, cross-spectral and autocorrelation analysis were performed to identify the periodic relationship between the groundwater level and tidal level in a typical coastal area. After eliminating the long-term trend, Fourier transform and inverse Fourier transform were performed on the groundwater level data to extracted 0.040-0.085 frequency. Weconcluded that in the coastal region which is strongly affected by human interference, this is a effective approach to identify the tidal effects on groundwater level from other factors, especially human disturbance.