基于高密度电法的岩溶储水构造识别

岩溶水的赋存具有时间和空间分布的不均匀性,高密度电法作为一种成熟高效的地球物理勘探方法,是开展地下水资源调查的主要手段之一。为研究高密度电法勘探在岩溶储水构造识别中的应用效果,本文在对汉中地区勉县幅1∶5万水文地质调查的基础上,针对地面调查过程中遇到的极度贫水山区,充分论证区内已知地质及物性资料,确立具有岩溶水找水前景的目标区域,开展高密度电法勘探综合研究工作。划分了岩性接触带和岩溶发育带的位置,圈定了可能的岩溶赋水空间,推断了地下水补给循环模式,为岩溶山区找水定井工作提供了有力依据。工作成果表明:①岩溶储水构造的发育受构造活动强度、地层岩性差异和地形地势条件共同影响;②在利用高密度电法进行勘探研究时,应充分结合地质地貌条件,测线宜穿越构造或岩性界线布设;③对于向斜构造、岩性接触带和地形共同控制的岩溶储水构造,建议将钻井布设于向斜构造轴部、地势相对较低的可溶性碳酸盐岩一侧。本文的研究工作对同类地区的岩溶储水构造勘探具有参考意义。

Identification of Karst Water Storage Structure Based on High Density Electrical Method

The occurrence of karst water has uneven distribution in time and space.As a mature and efficient geophysical exploration method,high-density electrical method is one of the main methods to explore groundwater resources.In order to study the application effect of high-density electrical exploration in the identification of karst water storage structures,based on the 1:50,000 hydrogeological survey of Mian County in Hanzhong area,this paper fully demonstrates the known geological and physical data in the area,establishes a target area with prospects for karst water prospecting,and carries out comprehensive research on high-density electrical exploration.The location of the lithological contact zone and the karst development zone is divided,the possible karst water supply space is delineated,and the groundwater replenishment circulation mode is inferred,which provides a strong basis forwater exploration and well determinationin karst mountainous areas.The work results show that:①The development of karst water-storage structures is influenced by the intensity of tectonic activity andthe difference of lithology and topography;②The geological and geomorphic conditions should be fully taken into account when the high density electrical method is used for exploration and research,and the survey line should be laid across structural or lithologic boundaries;③For the karst water-storage structure controlled by synclinal structure,lithologic contact zone and topography,it is suggested that drilling should be arranged on the side of soluble carbonate rock with relatively low topography at the axis of syncline structure.The research work in this paper has a good reference significance for the exploration of karst water-storage structures in similar areas.