用电阻率测深法探测地下水的矿化度——以银川平原为例

Application of electronic resistivity sounding method detected the TDS of groundwater——Yinchuan Plain as an example

通过对银川平原孔旁电测深数据与钻孔的岩性、水质资料分析,认为地下水水质评价的重要参数之一,即矿化度与电阻率关系密切.利用地质数学统计方法建立含水岩组电阻率与地下水矿化度相关数学模型得出:银川平原南部淡水区形成与黄河补给关系密切,由黄河向平原总体为由淡向咸的变化规律;西部淡水区范围受控于大气降水及贺兰山山洪垂直入渗以及基岩裂隙水侧向补给;中北部咸水分布范围受控于东部近黄河处第三系隆起,使得第三系高矿化度水向上顶托补给第四系,并向西顺层径流,造成银川平原地下水咸淡水界面总体呈现西深东浅之特征.

It has significant realistic meaning to detect the TDS of groundwater directly by the electronic resistivity sounding method, especially in the area that highly mineralized water is distributed extensively. The electronic resistivity sounding method can be used to delimit the range of fresh groundwater and improve success rate of drilling. TDS as a significant parameter to appraise the quality of groundwater has close relation with the electronic resistivity. The mathematic modeling that aquifer electronic resistivity is correlative with the TDS of groundwater by the geological mathematic statistic method showed that： the range of fresh water in the south of Yinchuan Plain had close relation with the Yellow River recharge, and it was gradually salted from the region close with the Yellow River to the inside of the plain; the range of fresh water in the west was controlled by the lateral flow from Helan Mountain, floodwater infiltration and precipitation; the interface of salt and fresh water in the middle-north area is deep in west and shallow in east that was controlled by the upheaval of Tertiary; and the highly mineralized water recharged upwards, and flowed along the stratum to west in Tertiary.