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低压多孔灌溉软管设计与评价方法的研究 总被引:2,自引:0,他引:2
低压多孔均匀出流灌溉软管是在低压管道输水灌溉基础上,结合沟灌和膜孔沟研究设计的一种新配套设施。本文在研究灌溉软管的有关水力参数基础上,研究设计出一种适合低压多孔均匀出流灌溉软管设计与评价的图解法,为灌溉工程设计与评价提供便利。 相似文献
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为了进一步探索低压微灌多孔软管的水力性能,采用室内试验方法,研究了低压(1~5m)条件下多孔软管的出流规律、沿程压力分布规律以及水头损失分布规律,结果表明,在低压条件下,多孔软管的水力特性受进口压力、出流孔孔距、铺设长度等因素影响,且受到管壁塑性变形的影响;沿程出流表现出单峰性,随管长及孔距增大,最大值点前移,随压力增大,沿程出流更为均匀;沿程压力一直减少,前半段减幅约为后半段的4倍,且随孔距增大,递减幅度变小;水头损失随孔距减小和压力增大而减小,且进口压力为1~3m时的减幅与4~5m时的比值在管长为40m时,其值约为管长为30m时的2倍。研究结果可为低压微灌技术的完善和发展提供理论依据。 相似文献
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1992年我所自行研制了“低压多孔口均匀喷洒灌溉管道” ,即在塑料软管上开很多均匀小孔使之与低压输水系统出水口配套。虽然实验取得了成功 ,但由于制造技术原始等原因 ,没有得到开发应用 ,1999年我所发现台湾生产的双羽式喷水软管与我们的想法类似 ,且采用激光造孔 ,生产工艺先进 ,于是进行了大面积示范应用。这种喷水软管可方便收放 ,沿管长均布激光打的小孔 ,每根管长 10 0m ,喷水压力 0 .0 5MPa ,喷洒均匀 ,省水经济。这种灌溉形式与现在使用的喷灌相比有如下优点 :①没有喷头 ,结构更加简单 ,价格低廉 ;②使用方便 ,收放快捷 ;③规… 相似文献
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温室内采用的供试作物为青椒,在土壤水分相同的条件下(土壤含水率下限为60%~70%,以占田间持水率的百分比计)通过试验对比分析了日光温室小管出流和沟灌2种灌溉方式对土壤温度、土壤水分、青椒叶绿素含量及长势、产量的影响。研究结果表明,在土层深度为5、15、25、35 cm时,小管出流的土壤温度较沟灌依次高0.24、0.23、0.17、0.30℃。在灌水前后的土壤水分空间分布及含水率均大于沟灌,小管出流灌溉方式下青椒的叶绿素含量较沟灌高6.8%,产量较沟灌增产34%,水分生产率比沟灌提高了0.9倍。 相似文献
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不同灌溉方式对日光温室青椒生长及产量的影响 总被引:1,自引:0,他引:1
为了确定日光温室内青椒的最适合灌溉技术,在日光温室内分别对青椒进行了滴灌、小管出流和沟灌3种灌溉方式的试验研究,分析了不同灌溉方式对日光温室青椒生长发育的影响。试验结果表明:不同灌溉方式对青椒株高、茎粗均无明显影响;相同阶段所测叶绿素含量,滴灌>小管出流>沟灌,且叶片叶绿素的含量和光合速率呈正相关;用显著性水平α=0.1对各处理产量进行方差分析表明,不同处理对产量有显著影响,青椒产量以滴灌最高,小管出流次之,沟灌最低;通过不同处理比较发现,沟灌、滴灌、小管出流水分生产率分别为16.17、35.13、31.59 kg/m3。故日光温室栽培青椒比较适合采用滴灌方式。 相似文献
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软管节水灌溉技术的推广应用钟山县农机推广站刘碧珍软管灌溉技术即是用定位或移动式灌水机械和移动式灌水软管、管道代替田间的灌水渠,完成水旱田的畦灌、沟灌和淹灌,并可与喷灌和滴灌装置配套完成喷灌和滴灌的一项节水新技术。它具有输水速度快、水量损失少、省地、便... 相似文献
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滴灌技术是当今世界上节水效果最好的灌溉技术。其主要特点是以低压小流量出流灌溉,实现局部灌溉。它是利用低压管道系统,使滴灌水成点滴地、缓慢地、均匀而又定量地浸润作物根系最发达区域,使作物主要根系活动区的土壤始终保持在合理含水状态。滴灌不同于传统的地面灌溉湿润全面积土壤,是一种缺水地区有效利用资源的灌水方式,同时还是一种现代化的农业技术措施。近年引进我国,并得到较快发展。 相似文献
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Behrouz Mostafazadeh-Fard Roghayeh Kavei-Deylami Sayed-Hossain Saghaian-Nejad Ahmad Jalalian 《Irrigation and Drainage Systems》2009,23(4):181-190
Meandering furrow irrigation (Gholam-gardeshi irrigation) is a modified form of furrow irrigation, which has being used in
Iran, but to date, there is no study about the erosion of this method of irrigation. To measure the erosion of meandering
furrow irrigation and to compare the results with standard furrow irrigation, two experimental fields with different soil
textures and furrow inflow rates were used. The experiment utilized a randomized factorial design with three replications
for each treatment. In both methods, the developed second order polynomial equation for the erosion, and advance equation
were able to predict the field data with coefficients of determination of more than 0.94. The results showed that the velocity
of advance, tail water runoff and erosion are significantly lower for meandering furrow irrigation as compared to standard
furrow irrigation. As the furrow inflow rates increased, erosion and runoff in both irrigation methods increased significantly. 相似文献
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为探明扶埂开沟膜下灌条件对作物土壤水分分布以及经济效益的影响,以温室番茄为研究对象,采用完全随机试验设计方法,通过时域反射仪进行水分观测,研究扶埂开沟膜下灌条件下土壤水分分布规律,以及该灌溉方式对温室番茄经济效益的影响.结果表明:扶埂开沟膜下灌,垄背的土壤剖面达到最大含水量时间迟于垄沟以及垄坡,垄背剖面观测点在灌水后184 h;在扶埂开沟膜下灌条件下,温室番茄在苗期内进行缺水灌溉的IWUE最大达到34.925 kg/(hm2·mm-1), 产量与商果率均较高,综合产生的净收入最高,经济效益达到最大值. 相似文献
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土壤入渗特性和田面糙率的变异性对沟灌性能的影响 总被引:2,自引:0,他引:2
以杨凌区粘壤土和砂壤土区域进行的大田沟灌试验为基础,在假定各灌水沟内部土壤入渗特性和糙率均一的条件下,重点分析各灌水沟之间土壤入渗参数和田面糙率的不同组合对沟灌水流运动过程和灌水质量的影响,结果表明土壤入渗特性的变异性对沟灌水流推进过程和灌水质量指标影响较大,在模拟时必须充分考虑;而田面糙率的变异性对沟灌水流推进过程和灌水质量指标影响较小,可采用田块糙率均值代替各灌水沟的糙率。经实例验证,水流推进过程相对误差为7.28%,灌水效率、灌水均匀度和储水效率模拟值与实测值误差分别为5.74%、6.18%和4.07%,结果表明其模拟效果较好。 相似文献
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棉花平膜灌溉的节水增产试验研究 总被引:3,自引:0,他引:3
何春梅 《中国农村水利水电》2003,(1):8-10
膜上灌较传统沟畦灌有较大的优越性,但由于覆膜改善了水流条件,灌水流速增大,当灌水流量大时,对灌水量难以控制,易产生余水,灌溉均匀度不易掌握;灌水流量小时,灌水时间太长,会与传统配水方法不协调等。平膜灌水法就是针对上述问题提出的,它是把沿田面坡度方向设置的灌水沟改为沿等高线走向布置,使水流在水平沟内流动,沟与地面全部采用地膜覆盖,灌水时,沟内的水量通过沟底渗水孔渗入土壤,达到湿润土壤的目的。新疆农业大学水利与土木工程学院采用这种方法,在哈密、昌吉等地对小麦、棉花、玉米等作物进行了田间试验,证明该方法可有效解决膜上灌存在的问题。 相似文献
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Mohammad Azmi Abdolmajid Liaghat Fahimeh Sarmadi 《Irrigation and Drainage Systems》2011,25(4):265-278
Various methods and criteria have been proposed and utilized for the evaluation of irrigation systems performance, which can be used for comparison of design conditions and irrigation systems performance. Surface irrigation systems should be paid more attention among all other irrigation systems due to their operation simplicity and high losses. In the present study, while describing main relationships of irrigation evaluation criteria of application efficiency, water requirement efficiency, Deep Percolation Ratio and Tail Water Ratio, a method based on SD will be introduced. Modeling of this approach has been done using VENSIM-DSS software. Model has been tested in a case study that included the modeling of a furrow in four irrigation status: current situation, full irrigation, deficit irrigation and finally deficit irrigation with optimized irrigation cutoff time and inflow into furrow. The results reveal the high capabilities of SD approach in modeling water resources and irrigation systems. Its user friendly and ability in transferring data to the data bank can introduce this approach and software as an applicable decision support system. 相似文献
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A 4-year field experiment was conducted in a semi-arid area to evaluate the response of each furrow and alternate furrow irrigation
in wheat-cotton system using irrigation waters of different qualities in a calcareous soil. Irrigation was applied to each
and alternate furrow of bed-planted wheat followed by ridge-planted cotton for comparison with standard check-basin method
of irrigation to both the crops. These methods of irrigation were evaluated under three water qualities namely good quality
canal water (CW), poor quality tube well water (TW) and pre-sowing irrigation to each crop with CW and all subsequent irrigations
with TW (CWpsi + TW). The pooled results over 4 years revealed that wheat grain yield was not affected significantly with
quality of irrigation water, but significant yield reduction was observed in alternate bed irrigation under canal water and
tube well water irrigations. In cotton, poor quality tube well water significantly reduced the seed cotton yield in all the
three methods of planting. The pre-sowing irrigation with canal water and all subsequent irrigations with tube well water
improved the seed cotton yield when compared with tube well water alone. However, this yield increase was significant only
in alternate furrow irrigation, and the yield obtained was on a par with yield under alternate furrow in CW. When compared
to check-basin irrigation, each furrow and alternate furrow irrigation resulted in a saving of 30 and 49% of irrigation water
in bed-planted wheat, whereas the corresponding savings in ridge-planted cotton were 20 and 42%, respectively. Reduced use
of irrigation water under alternate furrow, without any significant reduction in yield, resulted in 28.1, 23.9 and 43.2% higher
water use efficiency in wheat under CW, TW and CWpsi + TW, respectively. The corresponding increase under cotton was 8.2,
2.1 and 19.5%. The implementation of alternate furrow irrigation improved the water use efficiency without any loss in yield,
thus reduced use of irrigation water especially under poor quality irrigation water with pre-sowing irrigation with canal
water reduced the deteriorating effects on yield and soil under these calcareous soils. 相似文献