中文摘要：

以壤土（Y）、黄绵土（L）、风沙土（S）3种土壤为供试土样,进行室内层状土柱实验,进行3种土样两两组合的两层性土柱实验和风沙土一黄绵土累次叠加的多层性土柱实验,共11个处理组合.采用定水头法,测定其饱和导水率（Ks）.具体处理为两层土：Y＋S,Y＋L,L＋S,L＋Y,S＋Y,S＋L（先后顺序分别表示土层上下）;风沙土黄绵土（S＋L）作为层状组合,逐次叠加至5层.结果表明：两层性土壤中,细质地土壤在下时,其有效Ks显著低于粗质地土壤在下时的有效Ks值,而两层土壤有效Ks主要由细质地土壤导水特性决定;对于两层土壤的多次叠加,Ks值随分层数目的增加有增大的趋势.

英文摘要：

Three different textured soils. Lou soil（heavy loam, Y）, loessial soil（mediate loam, L） and sandy soil （sandy loam, S）, were selected as experimental soils in this study. 11 treatments of different combinations of layered soils were established to determine soil saturated hydraulic conductivity by soil column simulation method. In 6 treatments, soil columns included two soillayers（Y＋S, Y＋L, L＋S, L＋Y, S＋Y, S＋L） and in the rest 5 treatments, soil columns contained multi-layered soil, which filled with mediate loam soil and sandy loam soil layers repeatedly from 1 times to 5 times（（S＋L）×l, （S＋L）×2, （S＋L） ×3, （S＋L）×4, （S＋L） × 5）. The letter order indicates the sequencing of layered soils from upper to lower levels in soil columns. The results showed that in the treatments of 2 soil layers, when soil layer of finer texture was below the other soil layer, the equivalent saturated hydraulic conductivity was significantly lower than the value when the 2 soil layers were switched. The equivalent saturated hydraulic conductivity of two-layer soil colunms were mainly affected by hydraulic conductivity of the finer textured soil layer. For the multi-layered soil columns, the equivalent satu- rated hydraulic conductivity tended to increase with the increasing number of soil layers.