钢筋混凝土箱型暗渠在调水工程中的应用

钢筋混凝土箱型暗渠是景电二期延伸向民勤调水工程中最主要也是应用最多的一种输水渠道形式。暗渠结构合理，在沙漠地区是一种很好的渠道结构形式。经过几年的运行，暗渠安全可靠，防渗效果好，管理方便。对沙漠地区兴修长距离、跨流域输水工程，积累了宝贵的经验。     

大口径现浇暗渠施工机具的应用及改进研究

现有现浇暗渠施工设备多适用于小管径管道浇筑,无法满足灌溉支渠、斗渠所需要的大口径暗渠管道施工需求。针对大口径现浇暗渠的施工需要,研制了牵引滑模式大口径暗渠施工机具及在其基础上改进的自行走滑模式大口径暗渠施工机具,并进行了两代机具的技术经济指标比较分析。     

箱型暗渠一次浇筑成型的技术研究

介绍了沙漠地区使用钢模台车使箱型暗渠一次浇筑成型的方法，钢模台车的结构形式及混凝土养护方法。     

晋南盆地低压暗渠输水系统的初步探讨

近几年来,我所先后在晋南盆地一些井水灌区和泉井灌区选点试验研究低压暗渠输水系统。截止目前,已有洪洞县、新绛县、介休县的清水灌区,以及临汾、夏县、运城、祁县等井灌区设点试验或在生产上采用暗渠输水,但大部分是在探索之中,规模较小。现根据我们的试验调查资料,讨论以下几个问题。一暗渠输水系统对晋南盆地农业增产的作用根据我们试验和调查研究的初步资料,暗渠输     

北墅水库输水暗渠破坏原因分析及

由于工程老化，年久失修，北墅水库输水暗渠墙体多处发生位移破坏，严重影响工程的正常使用。通过对输水暗渠墙体破坏区受力状态的初步分析，找出了输水暗渠破坏原因，得出了破坏区墙体与拱座是分离的、直墙顶不承受拱荷载作用、在墙背回填料和较高外水压力作用墙体不满足抗倾安全要求而破坏的结论，提出了衬砌加固处理措施。     

1SZA辅助暗渠作业机的设计研究

辅助暗渠作业是一项有效的深松机械整地技术,可改善土壤构造,提高作物产量.为更好地实施该项技术,设计研制出1SZA辅助暗渠作业机.概述该机具的总体设计方案,介绍整机结构设计、工作原理及主要技术指标,详细分析各主要工作部件的设计.     

尔王庄暗渠泵站机组优化运行探讨

针对尔王庄暗渠泵站利用率高的要求以及机组出水结构的特点，对水泵机组进行了运行测试及研究：提出了泵站优化运行方案。实践结果表明实时根据水位及输水量等优选开机台数，优选叶片角度，可使泵站功耗大大降低。     

地下水超采区的回灌补源技术与模型分析

针对地下水超采引发的环境问题,以博兴县地下水漏斗区建设的暗渠回灌补源工程为例,介绍了暗管回灌补源的工程设计与实施效果;建立地下水数值模型,分析了暗管补源技术的补源效果及地下水位恢复情况,并设计了地下水暗渠回灌补源工程、地表水-地下水的联合调蓄[1]、雨洪水资源利用、压采地下水等方案进行模拟预测,预测了不同方案条件下的地下水超采区的修复效果,为地下水回灌补源工程提供了科学的技术支持。     

钢模台车在沙漠区暗渠施工中的应

甘肃省景电二期延伸向民勤调水工程是一跨流域长距离调水工程, 有八十多公里的渠道穿过腾格里沙漠，自然环境恶劣,施工条件艰苦;运用独立研制开发的钢模台车,成功完成了沙漠区钢筋混凝土箱型暗渠施工,进度快,质量好。     

花生喷灌效益大

本文介绍了山东曲阜县前孟村1977年以来建成的3000亩移动式喷灌系统,该系统共修灰土暗渠2.52万米,配有60台轻型喷灌机组,每个机组配带PYS—15喷头8个。经过六年的观测试验,摸索曲了花生喷灌的需水规律、各生育期的适宜土壤含水     

Trickle irrigation timing and its effect on plant and soil water status

Tomato plants on Sinai sand dunes were irrigated daily by drip irrigation. The irrigation was supplied during daytime hours for one field and a short time after sunset for the second. Results showed that daytime irrigation of soil with low water holding capacity increased the yield significantly and improved plant water potential as well as water use efficiency. The dominant component of water balance under these conditions was found to be deep percolation, which accounted for more than 70% of the water budget. Controlling this component rather than soil water status requires measurements of flux as input for managing the quantity of water to be applied. It is concluded that during hours of high net radiation flux, transpiration rate can best compete with deep percolation rate. Based on this conclusion, the use of net radiation flux as input is recommended for the best irrigation timing.     

初始含水率对土壤垂直线源入渗特征的影响

为解决现有渗灌系统在深根系植物应用中存在的问题，该文设计了一种垂直线源灌水器，并通过室内土箱试验研究了不同初始含水率条件下砂黄土和塿土的垂直线源入渗特征。结果表明：Philip入渗公式的形式能够较好地描述2种土壤的三维入渗过程；入渗时间一定时，砂黄土和塿土的累积入渗量均与初始含水率之间呈二次函数递减关系；2种土壤入渗的最大径向距离、最大垂向距离、宽深比均与初始含水率之间呈二次函数抛物线关系；2种土壤相比，偏砂性的砂黄土累积入渗量在低初始含水率下较塿土大，但随着初始含水率的增加其减小速度较塿土快，偏黏重的塿土入渗临界初始含水率较砂黄土大，但其入渗范围较砂黄土小。这些结果可为不同土壤条件下的垂直线源灌水技术发展提供参考。     

CaCl2溶液灌溉对土壤水盐与斥水性分布的影响

选用砂土和盐碱土并添加斥水剂,采用0、1、3和6g/L的CaCl2溶液进行室内土柱入渗试验,对比灌水水质对土壤水盐及斥水性分布的影响。结果表明:咸水灌溉后,砂土1和亲水盐碱土的累积入渗量、湿润锋和入渗率曲线均较光滑;而砂土2和斥水盐碱土的入渗特征曲线不如砂土1的光滑,入渗过程比前者慢得多。灌水矿化度增加对盐碱土的入渗过程影响更明显。Philip模型与Kostiakov公式拟合亲水土壤入渗率过程都较好。砂土1和砂土2在咸水灌溉后剖面的滴水穿透时间都比初始值有所增加,但最大增加值仅3.6 s。盐碱土灌后剖面的滴水穿透时间增加明显,最大增加值为19 s。灌水矿化度增加对电导率、Ca2+质量浓度和Cl-质量浓度分布均有影响。研究表明咸水灌溉不仅影响水盐分布,而且对斥水性也有不同程度的影响。     

新疆砾石地葡萄滴灌带合理设计及布设参数的数值分析

为了摸清新疆含砾石复杂土壤条件下土壤水分运动规律,优化葡萄滴灌系统设计中的各项设计参数及合理布设,该文通过田间交汇试验确定合适的滴头间距为30 cm,并借助Hydrus-2D数值模型确定了土壤水力参数,同时运用该数值模型模拟了不同滴头流量和滴灌带水平间距布设形式下地表滴灌土壤水分分布特征。根据土壤湿润体特征结合葡萄根系分布规律,确定新疆砾石地葡萄滴灌系统合理的滴头流量为2.5～3.0 L/h,滴灌带水平间距为60 cm。该结果可为新疆砾石地复杂土壤葡萄滴灌系统的科学设计和田间合理布设提供参考。     

Impact of irrigation with treated low quality water on the heavy metal contents of a soil-crop system in Serbia

Water availability for irrigation is a limiting factor for agriculture in Mediterranean countries. An upcoming strategy for increasing water supply is to use treated wastewater for irrigation. A principal drawback of irrigating with wastewater is the potential heavy metal accumulation in soil and foodstuff.Accumulation of heavy metals in soil and potato plants (Solanum tuberosum L.) irrigated with treated low quality surface water was studied in a three years experiment. The low quality surface water used for irrigation experiments contained a significant proportion of urban sewage and was spiked with selected heavy metals (Cd, Cr, Cu, Pb) and arsenic before treatment for years 2 and 3.The experiments were carried out during the growing seasons of 2006, 2007 and 2008 on a humogley soil of a commercial vegetable farm, 10 km north of Belgrade, Serbia. The growing seasons started in April/May and finished in August. Irrigation water was treated using (1) a conventional sand filter treatment, and (2) a sand filter combined with a specific filter for heavy metal removal treatment.Irrigation water composition was highly variable and cases both of enrichment and depletion of the measured inorganic trace elements were observed in the treated water, compared to the low quality feed water.In spite of this variability of the irrigation water composition, the soil contents in inorganic elements at the end of the three irrigation years are similar to the initial state. After the third harvest, no impact of the irrigation water on potato quality could be detected except for total sugar and sugar in total solids. Statistical tests (ANOVA) were performed to assess similarities between the different set of samples.The principal conclusion of this investigation is that, when appropriately treated, low quality feed waters with high heavy metal contents can be used for irrigation over several years without significant degradation of soil and produces. Even though, long-term cumulative effects in other pedologic and hydroclimatic settings, irrigation and cropping conditions cannot be excluded.     

戈壁葡萄膜下滴灌土壤水分动态规律的研究

以酿酒葡萄为实验材料,设计2 400、3 000、3 600、4 200m3/hm2四个不同滴灌量的膜下滴灌处理和3 600m3/hm2的不覆膜处理,在每次滴灌后每隔2d取20、40、60、80cm四个不同土层的土样进行烘干处理。结果表明,在不同滴灌量下20～60cm土层的土壤质量含水率受自然蒸发和葡萄的蒸腾失水影响明显。在3 600m3/hm2的灌溉量下,覆膜处理下20～40cm和40～60cm的土壤质量含水率分别比不覆膜的处理高出15.60%和18.83%,说明覆膜处理比不覆膜处理能更好的保持土壤质量含水率,可以节约大量灌水。     

滴灌条件下山区典型土壤水分运移规律分析

在广西山区选择沙土、壤土和黏土等3种典型土壤,并开展滴灌在这3种土壤条件下的土壤水分运移规律研究。试验结果表明:1在地埋黏土、壤土和沙土以及0.10 MPa工作压力条件下,滴灌管的单米流量为4.17、5.92和6.10 L/h,为地表自由出流的67.58%、95.05%和98.87%;2滴灌在黏土的水分运移形状基本为圆形,在沙土和壤土的湿润形状为上小下大的椭圆形;3同等条件下,水分在沙土的水平和垂直向下运移速率最大,壤土次之,黏土最小;4在土箱相同位置,黏土的土壤含水率最大,壤土次之,沙土最小;5根据滴灌的土壤水分运移规律,提出滴灌管在广西山区沙土、壤土和黏土的适宜埋深分别为10、15和20 cm;6滴灌应用在山区条播作物时,在黏土、壤土、沙土的适宜滴孔间距应为35、30和25 cm。     

小滴头流量下灌水频率对膜下土壤湿润区的影响

为了探明灌水频率对小滴头滴灌土壤湿润区的影响,在实验室对沙土和中壤土进行了膜下间歇滴灌试验,滴头流量分别为0．3、0．5、0．7L／h;灌水频率分别为1、2、3、4次灌完。在灌水量相同的情况下观测了土壤的湿润区运移过程和含水率分布。结果表明,小滴头流量下改变滴水频率对土壤湿润体的大小影响很小;随着灌水频率的增加,土壤湿...     

设施栽培反馈自控低压灌溉系统研究

通过设计不同管径管道配置形成低压灌溉管道,并利用土壤含水量变化产生的水势变化研究反馈自控灌溉技术,形成一种设施栽培反馈自控低压灌溉系统.该系统具有低压、节能,并可以实现自动控制灌溉,投资省,适用性广,兼备自流灌溉和滴灌的优点.     

Effects of sand column, furrow and supplemental irrigation on agricultural production in an arid environment

The effects of supplemental irrigation, sand columns and blocked furrows on soil water distribution and barley yield were studied on arid soils affected by surface crusts. The sand columns were 50 mm diameter, 600 mm deep, and filled with sand of 0.375 mm mean diameter. The blocked furrows were trenches about 250 mm deep, 300 mm wide, and 6 m long established perpendicular to the slope direction. Sand column and furrow treatments significantly increased soil water storage compared with natural or control treatments. Soil water storage significantly increased by about 210% and 230% near the center of the sand column and the furrow treatments, respectively, relative to the control treatment. For sand column treatments, soil water storage decreased linearly with distance from the center of the sand column to about 2.5 m, while for the furrow treatment soil water storage decreased logarithmically to a distance of about 1.0 m, beyond which the soil water storage was not significantly different from the natural or control treatments. The furrow and sand column treatments significantly increased the water application efficiency, seasonal consumptive use and barley grain and straw yields compared with natural and control treatments. Increasing furrow spacing increased the catchment area and consequently crop production per furrow, but decreased crop production per unit total (cultivated and catchment) area. Decreasing sand column spacing reduced surface runoff and increased soil water storage and consequently barley grain and straw yields. Supplemental irrigation is essential for grain production in limited rainfall areas. Soil management is also required to overcome the problems of the soil surface crusting and the low permeability of subsurface soil layers for maximum rainwater efficiency, and for optimal crop production with minimum supplemental irrigation water. Where agricultural land is not limited, furrowed soil surfaces appear to be the most suitable technique for barley grain production. Sand columns with sprinkler irrigation might be more suitable for growing barley as forage crop where agricultural land is limited. Received: 19 October 1998