压力水头与土壤容重对微润灌溉水分入渗的影响

发布时间：2018-06-07 17:24

  本文选题：微润灌溉 + 压力水头　； 参考：《干旱地区农业研究》2017年04期

【摘要】：为探究微润灌溉条件下水分在不同压力水头、不同容重土壤中的入渗情况,通过室内土箱模拟试验,分别设置h=2.0、1.5、1.0 m的压力水头,土壤容重γ分别为1.20、1.30、1.40 g·cm~(-3),测定累计入渗量、湿润锋及土壤含水率3个指标。结果发现,水分累计入渗量与压力水头为正相关关系,与土壤容重为负相关关系;微润管在空气和地埋出流情况下的流量与压力水头均为线性增函数关系,相同压力下,微润管的空气出流量明显大于地埋流量,微润灌溉系统更适宜采用地下埋管方式;湿润锋是以微润管为中心的近似圆形,水平运移距离与垂直向下运移距离均大于垂直向上运移距离,重力对微润灌条件下水分运移有一定的作用,但该作用随着土壤容重的增加逐渐减小;湿润锋运移距离与时间的关系近似为幂函数关系,入渗指数约为0.5;土壤容重越大,水分在土壤中的入渗速率越小,土壤对水分的蓄持能力越弱;经计算,微润灌溉的灌水均匀性符合要求。
[Abstract]:In order to investigate the infiltration of water in different pressure head and different bulk density soil under micro-moisturizing irrigation condition, through the laboratory soil tank simulation test, the pressure head of 1.51.0 m was set up, the soil bulk density 纬 was 1.20 ~ 1.301.40 g / cm ~ (-1) ~ (-1) ~ (-1) C ~ (-1), and the accumulative infiltration amount was determined. Moisture front and soil moisture content. The results showed that the cumulative infiltration of water was positively correlated with the pressure head, and negatively correlated with the soil bulk density, and the flow rate and pressure head of the micro-embellished pipe under the condition of air and buried discharge were all linear increasing function, and under the same pressure, the relationship between the flow rate and the pressure head was linear. The air discharge rate of the micro-wetting pipe is obviously larger than that of the buried pipe, so the micro-wetting irrigation system is more suitable for the underground buried pipe, and the wetting front is an approximate circle centered on the micro-embellish pipe. The horizontal migration distance and vertical downward migration distance are both larger than vertical upward migration distance. Gravity has a certain effect on water migration under the condition of micro-irrigation, but this effect decreases gradually with the increase of soil bulk density. The relation between moisture front migration distance and time is approximately a power function, and the infiltration index is about 0.5. The larger the bulk density of soil is, the smaller the infiltration rate of water in soil is, and the weaker the holding capacity of soil is. The irrigation uniformity of micro-moisturizing irrigation meets the requirements.
【作者单位】： 太原理工大学水利科学与工程学院;
【基金】：国家自然科学基金(31271645) 山西省农业科技攻关项目(20140311007-4)
【分类号】：S152.7;S275
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本文编号：1992048