单点膜孔入渗特性的试验研究

Experimental research on infiltration from single hole of membrane

膜孔入渗是指在覆膜灌溉中，水通过膜孔渗入土壤的过程．作者对陕北榆林壤土进行了５种膜孔直径的单点膜孔入渗室内试验，观测并分析了累计入渗量、湿润深度及表面湿润半径随入渗历时的变化规律．结果表明：①单点膜孔的累积入渗量变化过程符合Ｋｏｓｔｉａｋｏｖ模型；②相对入渗参数（单点膜孔入渗参数与垂直一维入渗参数之比值）与膜孔直径具有显著的相关关系；③单点膜孔的湿润深度小于垂直一维入渗的湿润深度，并且相对湿润深度（单点膜孔的湿润深度与垂直一维入渗的湿润深度之比值）与膜孔直径具有显著的相关关系；④单点膜孔入渗的表面湿润半径与入渗历时符合幂函数关系，并与膜孔直径存在着显著的相关关系；⑤在相同入渗历时的情况下，与垂直一维入渗相比，膜孔入渗的湿润土体平均含水率较小．

The experiments of infiltration from membrane hole for five diameters are carried out in lab by using loam soil.Cumulative infiltration,wetted depth and wetted radius are observed.The results show that:1 The relationship between cumulative infitration of single hole and infiltration duration conforms to Kostiakov model;2 The relativity between the hole diameter and the relative infiltration parameter is significant,3 The wetted depth of membrane hole is less than that of vertical infiltration and the relationship between the hole diameter and the ratio of wetted depth of single membrane hole to wetted depth of vertical infiltratoin is obvious;4 The relation between wetted radius on soil surface and infiltration duration conforms to power function;5 The average moisture of the wetted soil for membrane hole infiltration is less than that for vertical infiltration.