电法探查海岸带含水层咸淡水界面的调查研究

Survey on fresh-saline groundwater interface in coastal aquifers with electrical techniques

本文在理论上对电法探查多层土层组成的海岸带含水层的咸淡水界面的可能性进行探讨的基础上,对太平洋沿岸某地区进行了实地调查研究。在测量设置在海岸附近及分布于海岸纵深方向的调查井垂直方向电导率的同时,在调查井附近进行了电法探查。结果表明,电法探查的咸淡水界面的深度与依据井水电导率区分的混合区域上端几乎一致,即对于不同类别土质构成的岩土层,电法不但能探查确定咸淡水界面的深度,而且与以往的手法比较也是一种简单、快速、可靠、成本低廉的确定咸淡水界面深度的方法。

On the basis of analyzing theoretically the feasibility of detecting fresh-saline groundwater interface in coastal aquifers composed of multi-layered geologic structure by electrical exploration, a field investigation on some areas near the Pacific Ocean was carried out in this research. The vertical conductivity of well water along the coast was detected with the parallel methods, and the same wells nearby were investigated by electrical prospecting. The results show that the depth of fresh-saline groundwater interface explored is almost the same with the upper part of the mixed area divided according to well water conductivity. Therefore, the electrical technique can be used to detect the depth of fresh-saline groundwater interface for the zone composed of multi-layered geologic structure. It is also a simple, fast, reliable and low cost detecting technique compared with traditional techniques.