【摘要】 [目的]本文研究了分层土壤的持水性能。[方法]以砂壤和细砂设计了3种不同分层(2、4和8层)土柱,开展室内饱和排水试验。与均质细砂和砂壤土壤进行比较,观察土柱从饱和到120 h末的持水量变化,测量试验土柱最终含水率剖面,利用HYDRUS-1D软件对分层土柱的入渗过程进行了模拟分析。[结果]砂壤与细砂的土壤分层结构能够提高土体持水能力,增加粗细土壤分层数量有助于提高土柱含水量。试验说明分层土柱的排水主要来自粗质土壤,相对细质土壤排水量较低,反映了粗质土壤上覆细质土壤界面存在的毛细屏障作用能提高上层土壤的持水能力。[结论]本研究对干旱和半干旱地区的水资源综合利用以及土壤修复、污染物填埋等具有一定指导意义。更多还原

【Abstract】 [Objective]This paper aimed to evaluate the water retention capacity of stratified soils.[Method]Indoor saturated drainage experiments were conducted in three types of layered soil columns(two layers,four layers and eight layers of sandy loam and sand,respectively).Compared with homogeneous sandy loam and sand columns,the soil water changes from 0 to 120 hours in different time interval were observed,the final soil moisture content profiles was measured,and a HYDRUS-1 D model was employed to imitate the drainage process for different soil columns.[Result]The combination of sand layer with sandy loam layer enhanced the soil water retention,and the increase of fine and coarse grained layers was supportive to soil water content.Furthermore,laboratory observation and software simulation confirmed that comparing soil moisture profiles,water drainage was mainly from sand layers more than sandy loam layers,which indicated that the capillary barrier between coarse grained layer underlying fine grained layer positively impacts water retention capacity for layer soil columns.[Conclusion]The results would be meaningful for water resource exploitation,polluted soil remediation and landfill contaminants prevention in arid and semi-arid areas.更多还原