竖管地下灌溉入渗特性试验研究

发布时间：2018-10-31 21:22

【摘要】：竖管地下灌溉是一种新型节水灌溉技术,由此形成的地下灌溉技术具有节水、节能、投资小、灌水均匀、不易堵塞及使用寿命长等优点。现有的地下灌溉灌水器抗堵、节能和节水性能无法同时实现,为了实现灌水器的这一优点,提出了竖管地下灌水器。采用室内试验、理论分析和计算分析等相结合的方法,开展竖管地下灌溉入渗特性的试验研究,以期为后续的研究提供借鉴。主要结论如下:(1)压力水头、竖管直径越大,累积入渗量和入渗流量越大,但随入渗时间增加,压力水头对累积入渗量变化的影响程度逐渐减小。入渗条件相同时,砂质壤土入渗量大于粉质壤土。当压力水头为0.5～3.0 m时,竖管灌水器稳定入渗流量为0.53～1.25L/h,流量变化范围较大。(2)影响入渗的因素较多,其中压力水头对累积入渗量的影响最大,是影响累积入渗量的主要因素,而竖管直径、土壤初始含水率和土壤容重也对累积入渗量有一定程度的影响,但土壤初始含水率对累积入渗量的影响最小。(3)浑水入渗试验表明:竖管直径对累积入渗量的影响最大,其次为土壤容重、灌水器埋深、含沙量和土壤初始含水率,压力水头对累积入渗量的影响最小。(4)竖管地下灌溉湿润体的呈椭球状,垂直方向和水平方向湿润峰的运移距离随着入渗时间的逐渐增加逐渐增大,但在入渗时间增加到某一时间点之后,湿润峰的运移距离增大幅度逐渐减小。水平方向上的湿润峰运移距离介于垂直向湿润峰运移距离的向上运移距离和向下运移距离之间。(5)构建了累积入渗量与各影响因素之间的量化模型,验证分析表明模型能够较好的反映累积入渗量与影响因素之间的关系。同时,构建了湿润峰运移距离的计算模型,验证表明其预测结果较好,能够反映湿润距离与因素之间的关系。
[Abstract]:Vertical tube underground irrigation is a new type of water-saving irrigation technology, which has the advantages of water saving, energy saving, small investment, uniform irrigation, difficult to block and long service life. The existing underground irrigation emitters are anti-blocking, energy saving and water-saving can not be realized at the same time. In order to realize this advantage of the irrigation emitters, a vertical pipe underground water emitter is proposed. By means of laboratory test, theoretical analysis and calculation analysis, the experimental study on infiltration characteristics of vertical tube underground irrigation is carried out in order to provide reference for further research. The main conclusions are as follows: (1) the larger the diameter of the vertical pipe, the greater the cumulative infiltration amount and the infiltration discharge, but with the increase of infiltration time, the influence of pressure head on the cumulative infiltration rate decreases gradually. When the infiltration conditions are the same, the infiltration amount of sandy loam is larger than that of silty loam. When the pressure head is 0.5 ~ 3.0 m, the steady infiltration flow rate of the vertical water emitter is 0.53 ~ 1.25L / h, and the variation range of the flow rate is large. (2) there are many factors affecting the infiltration. The pressure head has the greatest influence on the cumulative infiltration, which is the main factor affecting the cumulative infiltration, while the diameter of vertical pipe, the initial moisture content of soil and the bulk density of soil also affect the cumulative infiltration to some extent. However, the effect of initial soil moisture content on cumulative infiltration was the least. (3) the experiment of muddy water infiltration showed that the diameter of vertical pipe had the greatest influence on the cumulative infiltration, followed by soil bulk density, depth of emitter, sediment content and initial moisture content of soil. The pressure head has the least effect on the cumulative infiltration. (4) the vertical and horizontal wetting peak migration distance increases gradually with the infiltration time increasing. However, when the infiltration time increases to a certain point, the range of migration distance of the wetting peak decreases gradually. The distance of wetting peak migration in horizontal direction is between the upward migration distance and downward migration distance of vertical wetting peak migration distance. (5) the quantitative model between the cumulative infiltration amount and the influencing factors is constructed. Validation analysis shows that the model can well reflect the relationship between cumulative infiltration and influencing factors. At the same time, the calculation model of the migration distance of the wetting peak is constructed, which shows that the predicted results are good and can reflect the relationship between the wetting distance and the factors.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S152.7

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