音频大地电磁法在探测地下水中的应用——以湛江南木水为例

Application of Audio-frequency Magnetotelluric (AMT) in groundwater exploration:a case of the Nanmushui area in Zhanjiang

本文通过在广东省湛江市省级生态农业示范区——南木水地区进行地下水探测拟解决当地的生活用水问题.该区域主要为燕山期花岗岩,本文采用了音频大地电磁法(AMT)勘探方法,从构造分析出发,选择三个有利区域(分别为A、B、C、区),布设了10条AMT勘探线,共166个测点,进行野外数据.对野外数据进行了一系列预处理、反演和电阻率成像得到各线的剖面图.分析研究剖面图和切片图,确定了三个可能含水的低阻带以及三口钻井的位置.其中C区已经打井取水,出水50 m^3/h,很好地验证了AMT方法在硬岩地区进行地下水探测的实用性和有效性.

In recent years, chemical agents such as fertilizers and pesticides have caused serious pollution to groundwater and surface water bodies in many parts of southern China have posed a threat to human health because of the development of agriculture. Therefore, it is difficult to explore ground water in hard rock area, but people have no choice but to prospect and employ the groundwater. In this study, Audio-frequency Magnetotelluric(AMT) was carried out to delineate ground-bearing zones in the Nanmushui area in Zhanjiang, Guangdong province. Based on the tectonic analysis, 10 survey lines were conducted along the river valleys and three positive zones of groundwater were identified due to the low resistivity images. One test drill was carried out to check out results of AMT survey and the capacity of the drill was 50 cubic meters per hour. So, the exploration validates the advantage of AMT method in groundwater exploration and this survey offers alternative freshwater source for local people.