考虑滴头堵塞位置的灌水均匀系数模型优化  

Optimization of drip irrigation uniformity model considering location of clogged emitters

作　　者：张若婵[1] 牛文全[1,2,3] 段晓辉[3] 李元[3] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,杨凌712100 [2]中国科学院水利部水土保持研究所,杨凌712100 [3]西北农林科技大学水土保持研究所,杨凌712100

出　　处：《农业工程学报》2017年第3期113-120,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金："十二五"国家科技支撑计划资助项目(2015BAD24B01)

摘　　要：为准确评价堵塞对滴灌工程灌水均匀性的影响,从确定采样点布置方式入手,利用HYDRUS-2D模拟不同堵塞情况下的土壤水分状况,首先分析灌水均匀性与土壤水分分布均匀性之间的关系,然后以土壤水分分布均匀系数为依据,在考虑滴头堵塞位置的基础上对灌水均匀系数模型进行优化,最后通过温室灌溉试验进行验证。结果表明,取样点布置方式对土壤水分分布均匀系数影响显著,适宜的取样间距和深度分别为60 cm及地表下20 cm。土壤水分分布均匀系数与不同灌水均匀系数之间存在良好的线性关系,且随着堵塞滴头数量的增加,堵塞滴头位置分布情况对土壤水分分布均匀性的影响增大。小区灌溉试验结果表明,当堵塞滴头数量较多时,土壤水分分布均匀系数与考虑滴头堵塞位置的优化灌水均匀系数具有较高的相关性,优于原指标,可较好反映由堵塞滴头位置改变引起的土壤水分分布均匀性变化,故在评价滴灌系统灌水均匀性时宜使用优化均匀系数。Uniformity is one of the most important indicators for the evaluation of drip irrigation quality, and is also regardedas an important parameter for drip irrigation system design. Soil water distribution uniformity is the ultimate expression of dripirrigation uniformity, but the present drip irrigation uniformity indexes can＇t reflect it directly. In this study, we used soil waterdistribution coefficient as the standard to evaluate the rationality and accuracy of 3 typical drip irrigation uniformitycoefficients （Christiansen uniformity coefficient, Keller uniformity coefficient and the uniformity coefficients consideringlocation of clogged emitters） and finally optimized the best one among these 3 coefficients. Three factors （clogged degree,proportion of clogged emitter, location of clogged emitters） influencing the drip irrigation uniformity were considered, and atotal of 27 kinds of drip irrigation situations （clogged degree of 40%, 60% and 80%; proportion of clogged emitter of 20%,30% and 40%; location of clogged emitters of even distribution, relative uniform and nonuniform distribution） were designed.The soil water distribution of each irrigation situation was simulated by HYDRUS-2D program and verified by an actualinfiltration experiment. We matched soil water distribution coefficient and the irrigation uniformity coefficients of eachirrigation situation, then compared and evaluated them by linear fitting. Soil water distribution coefficient was significantlyinfluenced by sampling arrangement, therefore 9 kinds of sampling arrangements were set up and a desirable one was chosenthrough variance analysis. Results showed that under the condition of the simulation test, the desirable sampling interval anddepth were 60 and 20 cm respectively for soil moisture monitoring. Based on the desirable sampling arrangement, there was asignificant linear relevance between soil water distribution uniformity and irrigation uniformity. Among them, the uniformitycoefficient considering location of clogged emitter

关 键 词：土壤水分 灌溉 优化 滴头堵塞 灌水均匀性 土壤水分分布均匀性 堵塞位置 

分 类 号：S275.4[农业科学—农业水土工程]