入渗水头及土壤体积质量对垄作沟灌土壤水分入渗和分布的影响

Effects of Infiltration Heads and Soil Volume-quality on Soil Water Infiltration and Distribution under Ridge Tillage Furrow Irrigation

采用室内土箱模拟试验,对不同入渗水头高度、体积质量的垄沟内湿润锋运移特性、入渗速率、灌溉需水量及含水率分布进行了研究。结果表明,相同体积质量条件下,随着入渗水头高度的升高,相同入渗时间湿周长度,湿润锋水平侧渗距离,垂向入渗距离均逐渐增加;水平侧渗距离与垂向入渗距离比值逐渐增大,说明入渗水头越高,水平侧渗距离越远。入渗速率在入渗初期最快,随着时间延长,入渗速率逐渐减小,最后趋于稳定入渗;相同时刻,水头高度越高,入渗速率越快。相同水平侧渗距离条件下,低水头比高水头垂向入渗距离更深;入渗水头越高,土壤体积质量越大,灌溉需水量越少。

Migration laws of wetting front,infiltration rate,irrigation water requirement and water content distribution were investigated by simulation tests using soil box indoor under different infiltration head heights,and volume and quality of furrows.The results revealed that under the condition of same volume and quality,the wet perimeter length,horizontal side seepage distance of wetting front and vertical infiltration distance increased gradually with the increase of infiltration head height.The ratio of horizontal lateral seepage distance and vertical infiltration distance gradually increased,which indicated that the higher the infiltration head,the greater the distance of lateral infiltration.The infiltration rate was the fastest in the initial stage of infiltration,and it gradually decreased with the prolongation of time,and finally tended to a stable infiltration.At the same moment,the higher of head height,the faster the rate of infiltration.Under the condition of same horizontal side seepage distance,vertical infiltration distance of low head was deeper than the high head.The higher the infiltration head,the greater the volume and quality of soil,and irrigation water demand was less.