滴灌土壤湿润体特性室外试验研究

采用室外试验研究与理论分析相结合的方法，在陕北米脂山地微灌枣树示范基地进行原状土的滴灌入渗试验，对单点源入渗情况下，不同滴头流量和灌水历时对湿润体形状、大小与湿润锋运移规律的影响，及不同参数组合情况下土壤水分的分布与再分布规律进行研究，结果表明：湿润体的形状近似为半椭球体；湿润锋的水平、垂向入渗距离分别与入渗时间具有极显著的幂函数关系；土壤含水率与湿润体特征值之间存在极显著的二项式函数关系，利用该函数关系能够精确地表示出滴灌单点源入渗土壤湿润体的水分分布与再分布过程，简单、易操作。

Investigation on Characteristics of Wetted Volume in Outdoor experiment under Drip Irrigation

Based on both single point-source infiltration experiment in natural soil, in Mizhi micro-irrigation base in the north of Shaanxi, and theoretical analysis, this paper studied the effects of discharge of emitter and irrigation duration on the shape, size and movement of wetting front. It also analyzed the law of soil water distribution and redistribution with different drip irrigation parameters. The results showed that the shape of wetting soil is similar to semiellipsoid and the infiltration length in both horizontal and vertical directions has a extreme significant power function relationship with infiltration time. Soil water content and the parameters of wetting soil have a extreme significant second power function relation, which could be used to describe the process of soil water distribution and redistribution of single point-source infiltration.