摘要：
青海共和盆地塔拉滩地区赋存丰富的第四系松散岩类孔隙水,含水层与隔水层之间电阻率差异较小,常规地面电法勘探所得结果认识模糊,准确划分地下水水位及含水层厚度有一定难度.笔者利用EH-4双源电磁系统频点密、垂向分辨率高的特点,在已知水井上开展了方法有效性试验,在与钻孔资料对比研究的基础上,计算出经验校正系数.之后,在工区开展MT"十"字剖面测量,对剖面数据进行了Bostick一维反演和EMAP 二维反演,对反演结果进行经验系数校正;综合一维、二维反演成果形成推断地质断面,据此定量判识地下水水位埋深、含水层厚度,最终成功布井,在设计深度获得了预期的出水量,大大提高了MT法定量解释精度.%Talatan area in Gonghe basin of Qinghai Province is rich in Quaternary unconsolidated rock pore water, characterized by similar aquifer and aquiclude resistivity. Therefore,the common ground electric prospecting results look fuzzy,and it is difficult to pre-cisely determine the groundwater level and the thickness of the aquifer. Using dense frequency and high vertical resolution characteris-tics of the EH-4 dual-power electromagnetic system,the authors made an effective trial above the known well. Based on a comparison with the borehole data,the authors calculated the empirical correction coefficient, then carried out MT "十" shape profile measuring and Bostick 1D inversion and EMAP 2D inversion to profile data in the work area,and checked empirical coefficient of the inversion re-sults. Through synthesizing 1D and 2D inversion results, the authors formed inference geological section to quantitatively identify the buried depth and aquifer thickness of the groundwater, and successfully determined well spacing. The expected water inflow was ob-tained at the designed depth,and the interpretation accuracy of MT method was greatly improved.
