瞬变电磁法与放射性勘探在深层水资源勘探中的应用研究

Application of TEM and Radioactivity Exploration in Deep Underground Water Resource Exploration

摘要: 大回线源中心方式瞬变电磁法在深层地下水资源勘探中有着非常广泛的应用。瞬变电磁法(TEM, transient electromagnetic method)采用的晚期视电阻率的计算方法有着明显边界效应，本文为了有效地压制边界效应采用了计算全区视电阻率的方法。为解决陕西某地区水资源严重短缺的问题，分别采用TEM和放射性测量法对该地区进行地下水资源勘察。地下含水断裂位置可通过视电阻率分布情况大致确定，断裂构造范围可通过放射性α射线异常来圈定，通过视电阻率和放射性α射线异常测量来相互映证，提高测量精度。本次工作达到预定目标，新确定的4口水井满足设计要求的单井喷水量达到50 m3/h，进一步验证了TEM与放射性勘探的综合应用在深层地下水资源勘探中的可靠性。

Abstract: The large loop source centered transient electromagnetic method is widely used in the exploration of deep groundwater resources. The calculation method of the late apparent resistivity adopted by TEM has obvious boundary effect. In order to suppress the boundary effect effectively, the method of calculating the all-time apparent resistivity is adopted in this paper. In order to solve the problem of serious shortage of water resources in a certain area of Shaanxi Province, TEM and radiometric methods were used to survey the groundwater resources in this area. The location of underground water bearing fracture can be roughly determined by the distribution of apparent resistivity, the range of fracture structure can be delineated by radioactive α-ray anomaly, and the apparent resistivity and radioactive α-ray anomaly measurement can reflect each other to improve the measurement accuracy. This work has reached the predetermined goal, and the newly determined four water wells meet the design requirements of single well water spray volume, which further verifies the reliability of the comprehensive application of TEM and radioactive exploration in the exploration of deep groundwater resources.