高密度电法在赣南地区不同地下水赋存类型的探测研究

Detection Research of Multiple Types of Groundwater Occurrence by Electrical Resistance Tomography in Ganzhou Area

为了解决赣南地区用水难的问题,本文利用高密度电法结合基础地质、水文地质和岩石电阻率物性资料,确定地下水赋存类型。然后针对不同地下水赋存类型,再分析其赋水模式、机理及物性差异,进一步综合解释反演结果,划分地层分界线、断裂构造和含水层空间,推测地下含水靶区。分别对孔隙水、基岩裂隙水、岩溶水地区找水打井进行实例分析,尤其针对白垩系红层地区,提出重点探测断裂构造带、地层不整合面和隔水岩层部位。根据高密度电法反演解释结果确定井位和井深,在几种地下水赋存类型地区实现极高的找水打井准确率。对比钻井资料,验证了高密度电法在不同地下水赋存类型中寻找水源的高效性,总结了高密度电法在不同岩性和不同地下水赋存类型中的找水经验,经专家评审,在赣南打井找水中实现了打井出水成功率超过80%。本文的应用研究成果为山区、边远灾区应急找水提供了重要依据。

In order to solve the problem of local water shortage.The multiple types of groundwater occurrence are detected by the electrical resistance tomography combined with fundamental geological,hydrogeology and rock resistivity properties in this paper.Based on the multiple types of groundwater occurrence,the water-bearing distribution patterns,mechanism and physical parametersare analyzed,and the resistivity inversion results are further comprehensively interpreted.Then through the illustration of groundwater exploration and well drilling in pore water,bedrock fissure water and karst water areas,the stratigraphic boundary,fault structure and aquifer space are divided to infer the further underground water-bearing target area.This paper proposes a focus detection of both fault structural belt,stratigraphic unconformity and water resisting rock stratum especially for the Cretaceous red bed area,in which the well location and depth are determined according to the interpretation of resistivity inversion by electrical resistance tomography to achieve high accuracy of water prospecting and well drilling in several groundwater occurrence types.Comparative drilling information verifies that the electrical resistance tomography is efficient in groundwater prospecting in multiple types of groundwater occurrence.The paper summarizes the experiences of electrical resistance tomography in groundwater exploration in different lithology and multiple types of groundwater occurrence.The succeeding expert review verifies thesuccess rate of over 80% waterwells digging in southern Ganzhou.The application results provide an important basis for emergency groundwater prospecting in mountainous and remote disaster areas.