摘要
为分析干旱区高盐度潜水蒸发条件下土壤中盐分积累规律,利用室外土柱模拟试验开展了不同TDS(Total Dissolved Solids)(30和100 g/L)、不同包气带质地(细砂和粉质黏土)和不同潜水埋深(0.5、1.0和3.0 m)的高盐度潜水蒸发条件下分层土壤盐分的监测工作。通过对各个土柱不同深度7次取样得到的土壤平均含盐量数据分析表明:高盐度潜水蒸发条件下,潜水埋深越浅,土壤剖面上相同深度范围内的含盐量就越大;在其他条件一定时,包气带质地为粉质黏土的土壤剖面含盐量大于包气带质地为细砂的土壤剖面含盐量;由于黏性土的膜效应和土壤中积盐对土壤孔隙的填充作用,导致粉质黏土土柱上层的土壤含盐量表现为潜水TDS为30 g/L的大于潜水TDS为100 g/L的,在土柱下层的土壤含盐量表现为潜水TDS为30 g/L的小于潜水TDS为100 g/L的;由于TDS升高对毛细水的重力和土体结构的改变,随着潜水TDS的升高,粉质黏土土壤剖面上出现局部积盐深度下移的趋势。
Column experiments were carried out to investigate effects of total dissolved solids （TDS） （30g/L and 100g/L）, vadose zone lithology （fine sand and silt clay） and depth of groundwater table （0.5m, 1.0m and 3.On） on distribution of soil salt accumulation under condition of high salinity phreatic water evaporation in arid areas. Samples were taken seven times from different depths of column for soil salt analysis. The resJhs indicate that under condition of high salinity phreatic water evaporation, the less depth the groundwtter table is, the larger soil salinity at the same depth will be. Salinity in soil profile with vadose zone lithology of silt clay is higher than that of fine sand when other conditions are fixed. In addition, soil salinity of phreatic water with TDS of 30 g/L is higher than that with TDS of 100 g/L in the upper layer of silt ,.,lay column due to the membrane effect of tenacious soil and filling effect of crystal salt in soil pore, aad lower in the lower part of the column. Depth of salt accumulation in silt clay profile tends to shift down with the increase of phreatic water TDS due to the change of capillary water gravity and soil structure as a result of higher TDS.
出处
《水利学报》
EI
CSCD
北大核心
2016年第2期150-157,共8页
Journal of Hydraulic Engineering
基金
国家自然科学基金-新疆联合基金重点支持项目(U1403282)
国家自然科学基金项目(51069016)
新疆自治区地方公派出国留学成组配套项目(XJDF201307)
新疆自治区水文学及水资源重点学科基金(xjswszyzdxk20101202)
关键词
干旱区
高盐度潜水
潜水蒸发
土壤积盐
arid area
high salinity phreatic water
phreatic water evaporation
soil salt accumulation
