基于温度和电导的地下水-海水交互作用研究

A Study on Groundwater-Seawater Interaction Based on Temperature and Conductivity

以中山大学珠海校区滨海水循环综合试验基地2006年12月到2007年3月地下水排泄区井群井水和海水温度、电导数据为基础,计算井水和海水温度平均值及变差系数,发现研究区域地下20m处存在含水层与海洋联通现象。使用混合比（End member mixing analysis,EMMA）、Mallet小波分解重构、互相关计算以及频谱分析等方法,对D5井水中混合海水含量以及海水对D5井作用机制进行研究,结果表明：D5井水中海水所占比例为9%~16%,海水对D5井能量贡献比为31%（其中12%通过海水-井水混合实现,19%通过介质传导实现）;D5中海水混合比的变动相对潮汐站水位变化存在5.5h相位延迟,其变化趋势及显著周期大致与潮汐站水位变化情况一致。

A new method based on water temperature and conductivity is used to study the interaction between groundwater and seawater in this paper. From statistical analysis of the data of water temperature and conductivity of the wells and seawater in Zhuhai Campus of Sun Yet-sen University, an aisle between groundwater and sea was found 20 meters beneath the studied region. At the same time, with end member mixing analysis, the percentages of sea water in the well D5 was estimated to vary from 9% to 16%. The heat contribution of seawater to D5 accounted for 31%, of which 12 percentage points of the contribution were from convection between seawater and wells, 19 points from conduction of solid-phase medium. From Mallet wave analysis and cross correlation and spectrum analysis, a 5.5h lag between the fluctuation of the percentage of sea water in D5 and that of the sea level was detected, both of which shared the same trend and cycles.