综合物探方法在渭北地下水勘查中的应用

Application of Comprehensive Geophysical Prospecting Method to Groundwater Exploration in Weibei Area

渭北地处鄂尔多斯盆地南部,地质构造复杂,地层岩性多为第四系松散岩、泥岩、白云岩等,含水性较差,寻找低阻断裂构造是该区地下水勘探的唯一途径。由于地球物理解释存在多解性,因此,单一的物探方法很难确定含水层的位置。对此,采用瞬变电磁法进行剖面测量判定低阻异常位置,放射性α法来圈定蓄水构造,激电测深法来准确判定地下水所在的层位及埋深等综合物探法进行探测。此外,通过正演模型,从理论出发,验证了综合物探法联合找水的可行性。

North of Weihe River is located in southern Ordos basin,and complicated geological structure,lithology is the fourth of loose rock,mudstone,dolomite with rather poor water-bearing property and permeability,thus to find out conductive faulted structures is the only way in groundwater exploration.Due to multiplicity geophysical interpre?tation,it is difficult to determine where the aquifer of the single geophysical method.In this regard,the transient elec?tromagnetic method was used to determine the location of low resistance anomaly,the radioactiveαmethod to delin?eate the water storage structure,and the IP sounding method to accurately determine the stratum and depth of ground?water.In addition,the feasibility of integrated geophysical prospecting combined with water prospecting was verified theoretically by forward modeling.