典型砂介质含水层渗透系数盐度效应研究

Salinity Effect of Permeability Coefficient of Sand Media Aquifer

渗透系数是计算含水层出水量、水库渗透量,以及溶质迁移规律研究等不可或缺的重要水文地质参数。为探究地下水盐度变化大地区渗透系数的盐度效应,以粗、中、细3种典型砂介质为研究对象,配制不同盐度的NaCl溶液,采用室内常水头试验,定量分析了盐度变化对砂介质渗透系数的影响。结果表明:(1)地下水盐度小于10 g/L时,盐度变化不会引起砂介质渗透系数明显改变;盐度大于10 g/L时,渗透系数随着盐度的增大而减小。(2)盐度变化引起地下水运动黏度变化是砂介质渗透系数产生盐度效应的原因。(3)对于不同粒径的砂介质,粗砂介质渗透系数的盐度效应最明显,中砂次之,细砂最小。

The permeability coefficient is an important hydrogeological parameter. In order to explore the salinity effect of the permeability coefficient of the area with high salinity of groundwater,three kinds of typical sand media,coarse and medium,were selected as the research object. Salt solutions with different salinities were prepared. The results show that when the salinity of groundwater is less than 10 g/L,the change of salinity will not change the permeability coefficient of sand media. When the salinity is higher than 10 g/L,the permeability coefficient will decrease drastically with the increase of salinity. Salinity changes caused by the changes in groundwater kinematic viscosity is the main reason for the salinity effect of sand media permeability coefficient. For sand media with different particle sizes,the salinity effect of the permeability coefficient of grit media is the most obvious,followed by medium sand and the smallest sand.