咸水入侵探测中电阻率法测量数值模拟研究

Numerical simulation of resistivity mothed in saltwater intrusion prospecting

近年来海(咸)水入侵已成为影响居民生活、制约工农业发展的重大问题,确定咸淡水界面是治理海(咸)水入侵的重要前提。根据咸淡水的电性差异,针对两种典型的咸水入侵地电模型进行正、反演计算,并研究了不同因素对电阻率法测量咸淡水界面的影响。结果表明:1电阻率法数值模拟可以较好地反映咸淡水界面的位置及形态;2咸化程度和现场实测范围内的粘土层电阻率变化对咸淡水界面的测量无明显影响;3测量极距主要影响反演剖面的分辨率,极距越小,分辨率越高。

In recent years,the sea water intrusion has become a serious problem for the residents living and restriction of industry and agriculture developing.Determining the salt-fresh water interface is the important premise of sea water intrusion management.According to the electric difference between salt water and fresh water,2Dresistivity forward and inversion of two typical saltwater intrusion geo-electric models were performed,and the effects of different factors on the resistivity measurement of salt-fresh water interface were studied.The results show that the numerical simulation of resistivity method can well reflect the position and the shape of salt fresh-water interface.There is no obvious effect of salinization degree and the change of clay layer resistivity within the measured range on the measurement of salt-fresh water interface.Measuring electrode spacing mainly affects the resolution of inversion profile,the resolution of resistivity profile increases with the decrease of electrode spacing.