【作者】 史文娟； 沈冰； 汪志荣； 宋孝玉；

【Author】 Shi Wenjuan, Shen Bing, Wang Zhirong, Song Xiaoyu (Institute of Water Resources, Xi’an University of Technology, Xi’an 710048)

【机构】 西安理工大学水资源研究所；

【摘要】 针对新疆地区大面积盐碱地垦区土壤剖面多呈层状且砂质夹层较多的特点,通过室内土柱模拟实验,研究了蒸发条件下不同层位夹砂层土壤剖面盐离子的动态变化情况。结果表明,砂质夹层对离子运动有较大影响。与均质土相比,层位较低的砂层可以促进盐离子向土表迁移;层位较高的砂层能有效的延缓各离子向土表迁移的速度并降低土表盐离子的含量,且使得更多的盐离子滞留于砂层以下土壤以及土、砂界面处,尤其是对于Na+更是如此;砂层层位越高,其对离子向上迁移的抑制作用越强。求得了砂层对Cl-和Na+起抑制作用的相对临界层位,为灌溉和排水设计提供了科学依据。更多还原

【Abstract】 Considering the fact that most the soil profile assumes the sand-layered soil in field in XinJiang region in China. The experiment on the changes of ionic concentration in soil profiles during water evaporation from sand-layered soil with the different sand position was carried out with soil column. The results showed that the sand layer in soil profile had an important effect on the Cl- and Na+ movement. When the distance between the sand layer and water table was more than 8cm and 2cm respectively, their upward moving velocities and concentrations in soil surface were smaller in layered soil than in the uniform soil, their concentrations in soil body under sand layer and at the interface between the soil and sand were greater than that in the uniform soil, especially for Na+ movement. The effect was intensified with the increase of the distance. The limited relative distance (i.e. the ratio of the distance to the buried depth of ground water) was calculated where the sand layer would start to restrain the ionic upward movement, this will provide further information for drainage design in field.更多还原