滨海地区潮汐对地下水位变化影响的统计学分析

Statistical analysis on impact of tide on water table fluctuation in coastal aquifer

本文采用互相关分析、谱分析、Mallat分解重构算法等理论与方法,利用实测的潮汐资料和观测井水位资料,并结合实测的电导数据,从统计学上分析计算了广东省珠海市唐家镇附近,滨海含水层地下水水位波动的原因以及波动的位相、周期、振幅对海潮潮汐的响应。结果表明,微承压水和基岩裂隙水水位波动的原因均是含水层承受的质量负荷随潮汐的变化而变化;微承压水水位波动相对海潮潮汐的位相延迟时间约为7.0h,基岩裂隙水约为1.5h;微承压水水位波动的周期组成成份比海潮潮汐略少,基岩裂隙水水位波动的周期组成成份与海潮潮汐基本相同;微承压水水位波动的振幅约为海潮潮汐的1/100左右,基岩裂隙水为1/3左右;本研究区域海潮潮汐对浅层基岩裂隙水水位波动的水平影响范围在1 000m之内。

The cause of water table fluctuation and the fluctuation phase, period and amplitude in the coastal aquifer responding to the tide in Tangjiawan, Zhuhai City, were analyzed by using cross correlation analysis, spectrum analysis and Mallat decomposition and reconstruction method according to the observed water table and conductivity data obtained from 17 wells inside the campus of Sun Yat-sen University, in the period from August 2006 to February 2007. The results show that the change of surface mass loading due to the tide is the primary reason causing the fluctuation of water table both in confined aquifer and bedrock fissure aquifer. The phase delay of confined water table and bedrock fissure aquifer water table is about 7h and 1 .5h latter than the relevant tide respectively. The amount of fluctuation period components for confined water is less than that of tide, while the amount for fissure aquifer is about the same as that of tide. The fluctuation amplitude of confined water is about 1/100 of the tide wave, hut the amplitude of fissure aquifer is about 1/3 of tide wave.