【摘要】 在温度场、湿度场和人工水渠等多场耦合作用下,土体与外界环境的热交换条件和水热输运过程的改变极易引起土体成分和结构的变异,从而引发区域的生态失衡和次生盐渍化。本文选择吉林西部的农安、大安、乾安和镇赉4个典型盐渍化地区作为长期观测和研究评价的地点,对多场(水、热、盐)循环条件下不同盖层盐渍土进行现场调查取样,对室外内的工程地质性质、物理化学性质和物质组成进行了长期观测和测试分析。结果表明:吉林西部盐渍土属于碳酸型盐渍土,水分迁移量为3.5%4.6%;易溶盐质量分数总体随深度增加而降低,并且盐水在剖面上的分布明显受到季节影响,旱季蒸发作用和冬季土体冻结作用促使盐分随水分向上运移,浅表土体盐分大量集聚;随深度增加,阳离子交换量的变化趋势基本与易溶盐质量分数变化的趋势相同。更多还原

【Abstract】 Under the coupling effect of temperature field,moisture field and artificial canals,the structure of soil can be easily changed by the heat transport and water migration process,which leads to regional ecological imbalance and secondary salinization.Four typical salinized areas including Nong’an,Da’an,Qian’an and Zhenlai were selected as long-term monitoring and evaluation areas.Under themulti-field condition,saline soils with different cover strata were collected and investigated in the field.The engineering geological properties,physico chemical properties and composition of studied soil were tested and monitored.The results showed that the saline soil in western Jilin belonged to carbonate saline soil,and the amount of water migration was about 3.5%-4.6%.Salt content generally decreased with increasing depth,and the distribution of water and salt in the profile obviously was affected by season.The effect of evaporation in dry season and soil freezing caused salt to move up with the water,and a large amount of salt gathered at the soil surface.With the increasing depth,the cation exchange capacity presented the same trend as salt content.更多还原