低压重力渗灌系统渗灌的特性

为合理设计温室内低压节水灌溉系统,探讨低压重力渗灌时的渗灌特性,设置以土壤初始含水量、土壤初始容重、供水高度和渗灌管埋深为主要调控因子,通过试验模拟分析低压重力灌溉条件下渗灌管的渗流规律及土壤水分的入渗特性。试验结果表明：渗灌管出流量与时间符合幂函数,渗水速率与时间符合三次方程;渗灌条件不同,灌后土壤湿润区以及湿润区土壤含水量的分布显著不同;渗灌湿润区水分分布受供水高度、土壤初始含水量、土壤初始容重及渗灌管埋深等因素的影响;通过显著性分析,4个单因素对渗灌管出流量影响程度由大到小依次为供水高度、土壤初始含水量、土壤初始容重及渗灌管埋深,且除埋管深度外,其他三因素交互作用显著。

Study on seep-irrigation characterization of irrigation system under gravitional force

In order to design properly a low pressure irrigation system for water sabing and to study the seep-irrigation characterization under gravitational force in greenhouse, a simulated test is conducted to study the infiltration rate of seepage-pipe and infiltration characterization of soil moisture by controlling the initial soil moisture, soil compaction, hydraulic height and depth of seepage-pipe under gravitational force. The test results show that infiltration capacity of the seepage-pipe varies with time in power-law, and the infiltration rate varies cubically with time. After irrigation, the area of wetting and soil moisture are influenced by hydraulic height, initial soil moisture, soil unit weight and depth of seepage-pipe in different degrees. The effects of 4 factors on infiltration rate are in descending order as hydraulic height, initial soil moisture, soil unit weight and depth of seepage-pipe. The interactions of hydraulic height, initial soil moisture and soil unit weight influence significantly on infiltration rate too.