直流电测深法优化组合在河西走廊山前戈壁区的找水效果

The effect of the application of optimal combination of direct electric sounding method to water exploration in pediment gobi area of the Hexi Corridor

不同水文地质条件下地下水的分布规律对各种物探勘查方法可能存在不同的地球物理响应。经对水文物探方法的试验研究,在山前戈壁不均匀含水区寻找可采第四系地下水,采用井旁测深试验、垂向电阻率测深扫面、激电测深详查和水文电测井等方法的直流电测深法优化组合勘查,取得了找水效果新的突破。研究结果表明:电阻率测深参数视电阻率(ρs)、激电测深参数极化率(ηs)、衰减时(St)、综合参数(Z)等的变化,与地层岩性结构、地下水矿化度高低及含水地质构造的分布相关;激电测深参数与地下水富水程度关系更为密切。

The distribution of groundwater under different hydrogeological conditions has different geophysical responses to various geophysical prospecting methods.Based on the experimental study of geophysical methods,the authors searched for the Quaternary groundwater in the non-uniform water area of the piedmont gobi,used such combinational means as sounding test beside the well,electric resistivity sounding sweeping,sounding of induced polarization detailed investigation and hydrology electric logging,thus achieving a new breakthrough in the search for water.The change of the(ρs)parameter of electric resistivity sounding and the(ηs,S t,Z)parameters of the sounding of induced polarization are closely related to the lithologic structure of the strata and the degree of mineralization of the groundwater and the distribution of geological structures.The parameters of the sounding of induced polarization are more closely related to groundwater richness.