音频大地电磁法在云南宣威白凹村碎屑岩层中找水的应用研究

Application of audio magnetotelluric method to find water in clastic strata of Baiao village of Yunnan Province

受场地条件及碎屑岩地层电阻率值低的影响,本文采用音频大地电磁法对云南宣威白凹村碎屑岩层进行找水研究。研究结果表明:在场地狭窄、地形起伏较大及电性差异不明显的碎屑岩地区,音频大地电磁法找水效果较好,可识别的有效异常为低阻中的相对更低的低阻区域;音频大地电磁法横向分辨率较高,探测深度大,能有效识别碎屑岩中的构造裂隙带或断裂破碎带发育段;卡尼亚视电阻率单支测深曲线纵向分辨率较高,能有效地分辨不同深度的岩土层结构,对划分地层有较好的效果。

Affected by site conditions and low resistivity of clastic rock formation,the audio magnetotelluric method is used to find water in the clastic strata of Baiao village,Xuanwei,Yunnan Province.The study results show that in the clastic rock area with narrow site,large topographic fluctuation and no obvious electrical difference,the audio magnetotelluric method has a good effect on water prospecting,and the identifiable effective anomaly is the relatively lower resistance region in the low resistance.Audio magnetotelluric method has high lateral resolution and large detection depth,which can effectively identify the development sections of the structural fracture zone or fault fracture zone in clastic rock.The vertical resolution of single sounding curve of Cagniard apparent resistivity is high,which could effectively distinguish the rock and soil layer structure at different depths,and has a good effect on stratigraphic division.