摘要

The aim of this study is to reveal the origin and evolution of groundwater as well as the interaction between groundwater, river water and seawater. During both the dry season (October and November) and the wet season (July and August) of 2009, the authors collected fresh river water and brackish water samples in Minjiang River estuary, groundwater samples near Minjiang River estuary, and seawater samples in Taiwan Strait, then measured salinity, D and 18O isotopic composition for the water samples. Some conclusions have been reached: (1) the unconfined groundwater on both sides of Minjiang River estuary is mainly recharged by rainfall, the groundwater on the northern side is also recharged by the bedrock fissure groundwater, and the groundwater on the southern side is also recharged by the irrigation water in the dry season, which has somewhat experienced evaporation before discharging; (2) the interaction between river water and groundwater always shows that the groundwater recharges to the river water occur in both dry season and wet season, and the mixing ratio of groundwater from the southern side of Min River estuary significantly increases in the dry season; (3) the seawater intrusion in the costal aquifer doesn't exist on the whole, and this kind of phenomenon just occurs locally in a small part of the costal aquifer; (4) the site and mixture type of the mixed zone between fresh and brackish water in the estuary in the dry season is clearly different from those in the wet season.

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