CAJ | 학술논문

华北平原东部浅层咸水与深层淡水构成“上咸下淡”的区域性水质结构。相关调查研究表明，浅层咸水越流补给深层淡水的过程并未使得深层水矿化度显著提高。为研究黏性土层是否能截留水中盐分，通过渗透试验计算分析了咸水通过黏性土层时的弥散作用。结果表明：(1)黏性土可有效截留咸水中的大部分盐分，证实了前人提出的华北平原东部深层弱透水层滤盐现象的存在；(2)黏性土截留盐分的能力随渗透系数和弥散度的减小而增大。据推测，黏性土滤盐的原因可能是咸水中 Na+被土壤胶体颗粒吸附或与土壤胶体吸附的一些组分发生了阳离子交换作用。
화북평원동부천층함수여심층담수구성“상함하담”적구역성수질결구。상관조사연구표명，천층함수월류보급심층담수적과정병미사득심층수광화도현저제고。위연구점성토층시부능절류수중염분，통과삼투시험계산분석료함수통과점성토층시적미산작용。결과표명：(1)점성토가유효절류함수중적대부분염분，증실료전인제출적화북평원동부심층약투수층려염현상적존재；(2)점성토절류염분적능력수삼투계수화미산도적감소이증대。거추측，점성토려염적원인가능시함수중 Na+피토양효체과립흡부혹여토양효체흡부적일사조분발생료양리자교환작용。
Regional water quality structure is const ituted by deep freshwater and shallowsalt water in the east of North China Plain ( NCP) . Evidences showed that salinit y of deep freshwater did not increase significantly when it was supplied by shal owsaline water. To examine whether the clay-bearing soil can intercept the salt from water, this study conducted the permeability tests to analyze the dispersion effects of saline water f lowing through the clay-bearing soil. The results showed that ( 1) clay-bearing soil can intercept most of salt in the saline water, which confirms t he existence of salt-filtering phenomenon in the east-ern deep aquitard of NCP; ( 2) the intercept capacity of clay-bearing soil increases with the decreasing of permeability and dis-persivity; and ( 3) the possible reason of salt-filtering is that Na+ in saline water is adsorbed by solid colloid part icles or has cat-ion exchange interaction wit h some com ponents absorbed by soil colloids.