蓄水条件下盐碱土中盐分空间变化特征

Spatial variation characteristics of salt in saline and alkaline field under impounding condition

根据陕西卤泊滩地区盐碱地整治工程,修建模拟装置,通过测定土体中盐分含量的空间变化,研究蓄水条件下土壤盐分的运移特征,为当地盐碱地治理提供理论支撑。结果表明,盐碱土土体一侧蓄水后,土体中的盐分顺着盐分梯度向水体中弥散,水体中的含盐量变化呈现由低到高的趋势,最终与土体间达到动态平衡;在土体垂直方向上,0~60 cm土体盐分减少,盐分含量主要集中在距地表100 cm左右处;在水平方向上,水体对于土体的作用范围为9 m,除此以外土体盐分含量变化不大。说明在试验该模型下,蓄水条件对距其一定范围内的盐碱土体具有改善效果。

According to the Lubotan saline and alkaline field consolidation project, the simulating device was built to study the distribution of salt under impounding by detecting salt content, which might provide theoretical support for local saline-alkali land management. The results showed that after impounding in the side of saline-alkali soil, the salt in soil layer dispersed to the water with the salt gradient, changes of water salt showed a trend from low to high, eventually the salt reached the dynamic balance between water and soil. In the vertical direction of soil profile, soil salt in 0 ~ 60 cm was reduced. Salt content of soil was concentrated in 100 cm below the surface. In the horizontal direction, water influential distance was 9 m, and soil salt which was more than 9 m away from the water was little changed. Therefore, saline and alkaline field could be improved under impounding condition in a certain range.