摘要
场地水文地质调查获取渗透系数常用抽水试验,然而抽水试验时间长、对低渗透含水层试验效果较差、易改变地下水流场等问题需要寻找其他方法替代。利用模拟装置对比抽水试验和微水试验获取水文地质参数的差别,讨论了地下水流场改变程度和试验精度。试验利用饱和氯化钠溶液作为污染源,观察试验装置各监测井中电导率值变化时间,证明在高渗透介质中抽水试验比微水试验更容易引起化学场及流场改变,加剧污染羽扩散;对比两种试验结果,抽水试验与微水试验采用Bouwer&Rice模型获得的渗透系数线性拟合相关系数R^(2)达到0.951 0,证明微水试验在潜水高渗介质中可替代抽水试验;对比试验时间,微水试验所需时间更短。因此,在高渗透介质的污染场地需要快速获得含水层渗透系数时,可优先选择微水试验。
Pumping test is a commonly used method to obtain permeability coefficient in site hydrogeological survey.However,it is necessary to find other methods to replace due to the problems such as long testing time,poor testing effect on low permeability aquifer and easy change of groundwater flow field.In this paper,the difference of hydrogeological parameters obtained by pumping test and micro-water test is compared with the simulation device,and the variation degree of groundwater flow field and the test accuracy are discussed.The saturated sodium chloride solution was used as the pollution source in the experiment,and the change time of the conductivity value in each monitoring well of the test unit was observed.It was proved that the pumping test in the high permeability medium was more likely to cause the change of chemical field and flow field than the micro-water test,so as to aggravate the diffusion of the pollution plume.Comparing two testing results,the correlation coefficient R^(2) of the linear coefficient of permeability coefficient obtained by the Bouwer&Rice model between the pumping test and the micro-water test reached 0.9510,which proves that the micro-water test can replace the pumping test in the submersible hyper permeability medium.Comparing the testing time,the time required by the micro-water test is shorter.Therefore,when the polluted site with high permeability medium needs to quickly obtain the permeability coefficient of aquifer,the micro-water test can be selected first.
作者
曹楠
张志鹏
孙东
周亚萍
熊雨霞
CAO Nan;ZHANG Zhi-peng;SUN Dong;ZHOU Ya-ping;XIONG Yu-xia(Chengdu Center of Hydrogeology&Engineering Geology,Sichuan Bureau of Geology&Mineral Resources,Chengdu 610081,China;Sichuan Huadi Environmental Technology Co,Ltd,Chengdu 610081,China;Sichuan Environmental Protection&Groundwater Pollution Prevention Engineering Technology Center,Chengdu 610081,China)
出处
《四川环境》
2021年第3期29-35,共7页
Sichuan Environment
基金
四川省地矿局科学计划项目2018。
关键词
微水试验
化学流场
渗透系数
地下水
Slug test
chemical field
permeability coefficient
groundwater
