共查询到19条相似文献，搜索用时 562 毫秒
1.
宁夏银北排水项目暗管排水外包滤料试验研究 总被引：4，自引：0，他引：4
采用一维和二维渗透模型对土工织物作为农田暗管排水外包灌料进行了试验研究,试验用的２种土壤取自宁夏银北暗管排水区,对１２种不同土工织物的透水效果进行了测定和对比分析,其初选结果将用于野外现场作进一步观测评价,并最终为宁夏银北暗管排水滤料选择提供依据。 相似文献
2.
宁夏银北灌区暗管排水反滤层试验研究 总被引：1，自引：0，他引：1
鄢俊 《中国农村水利水电》2000,(8):21-24
根据宁夏银北灌区的土壤特性和排水暗管布置形式及位置,在现场选取了三组具有一定代表性的土样,分别对短纤针刺土工织物、机织土工织物和纺织土工织物进行了八组暗管排水反滤层试验。并对试验成果进行了分析,为合理选择暗管排水滤层提供了科学依据。 相似文献
3.
宁夏银北灌区暗管排水技术应用与工程效果监测 总被引：3，自引：1，他引：2
宁夏银北灌区引进机械施工的暗管排水工程施工技术,开展了大面积的暗管排水工程建设。在对暗管排水效果、工程质量监测的基础上,对暗排区土壤盐分动态、地下水动态、排水水质、工程的管理等进行跟踪监测,总结出暗管排水工程成功的经验、不足,为暗管排水工程的实施提供有益参考。 相似文献
4.
宁夏银北灌区暗管排水技术应用现状调查分析 总被引：3，自引：0，他引：3
《中国农村水利水电》2019,(2)
在对宁夏银北灌区暗管排水工程应用现状进行实地调研的基础上,分析了银北灌区暗管排水工程的特点,选取典型暗管排水项目区进行周期性监测,一方面肯定了暗管排水在银北灌区治理盐渍灾害、改良中低产田中所发挥的巨大作用,另一方面对灌区暗管排水技术所面临的问题及存在的弊端进行了归纳整理,基于灌区暗管排水工程现状,提出了建设性意见,以期作为银北灌区及类似地区暗管排水工程的规划设计、施工及运行管理的参考依据。 相似文献
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农田暗管排水循环利用是缓解灌溉水短缺的有效途径之一,而具备净化水质作用的暗管外包滤料是保障回归水质量的关键。选取宁夏银北灌区暗管排水工程现场基土,配以3种吸附性材料和当地通用的1种无纺土工布,设计了仅敷裹土工布和铺设土工布+单一吸附性材料的初设方案,利用课题组研发的土柱渗透试验装置进行筛选试验并根据初试结果,进一步设计出土工布+混合吸附性滤料的改进方案。试验中分别测试了外包滤料不同铺设型式下的流量衰减过程、渗透系数变化规律、盐分去除率及吸附量达到饱和的持续时间。结果表明,在排水性能方面,铺设土工布+10 cm厚吸附性滤料的方式优于仅敷裹土工布方式;铺设土工布+混合吸附性材料的方式优于土工布+单一吸附性材料的敷设方式。在净化水质方面,经水洗处理的秸秆与炉渣混掺铺设,去除水中盐分效果明显,吸附量达到饱和历时长,能够同时满足滤土排水和净化水质的要求。 相似文献
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为了探究不同外包滤料条件下的暗管排水性能和土壤脱盐效果,基于室内试验研究成果,在田间设置4种暗管排水系统(各系统中暗管埋深均为80 cm,间距均为20 m),所用外包滤料分别为68 g/m2土工布(L)、砂滤料(S)、68 g/m2土工布+砂滤料(LS)和无外包滤料(W),以当地常规明沟排水(CK)作为对照,通过田间试验分析了春灌过程中各暗管系统的排水性能指标及土壤脱盐效率.结果表明:相比处理W,处理L,S和LS平均排水速率提升了7.44%,12.55%和15.75%,平均流量衰减度降低4.07%;处理S和LS累积排水量提高了5.11%和8.31%(P<0.05).各暗管处理春灌后平均土壤脱盐率均达47%以上,较CK提升显著,其中处理LS效果最优,为50.94%.综上,应优先选择处理LS作为河套灌区暗管排水系统外包滤料布设方案.该研究结果可为河套灌区暗管排盐技术的推广应用提供理论支撑和科学指导. 相似文献
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太阳能暗管排水对银北灌区油葵土壤环境及产量影响 总被引：2，自引：0，他引：2
针对土壤盐渍化严重影响了宁夏银北灌区土壤环境和作物产量的问题,通过太阳能暗管排水区和非暗管排水区对比试验方法,着重研究了2017和2018两年太阳能暗管长时间持续排水对土壤环境和油葵产量的影响。结果表明:太阳能暗管排水可以有效改善土壤环境,使两年的地下水平均埋深分别增加4.5%和6.4%,地下水平均矿化度分别降低7.9%和9.0%,两年土壤平均脱盐率分别为4.7%和8.2%,对表层土壤的脱盐效果最为明显。同时提高了油葵产量和水分生产效率,两年油葵产量分别提高13.8%和21.6%,灌溉水分生产效率分别增加13.3%和21.8%,作物水分生产效率分别增加16.4%和22.9%。综合试验结果和经济成本考虑,油葵生育期灌水2次、播前灌水1次、冬灌1次,生育期5-9月持续排水,这是适宜惠农当地太阳能暗管排水条件下油葵的灌排制度。 相似文献
8.
雷达艮 《中国农村水利水电》1985,(7)
我所1981年在武汉市国营四新农场建立了农田地下排水试验点(试区布置见本刊1984年2期9页)。1981年至1983年对暗管(沟)田间排水性能(下称排水性能)作过试验。其结果是:“水泥砂土暗管与波纹塑料暗管排水性能差别不大。暗管排水性能大大优于滤料暗沟。而稻壳滤料暗沟又优于砂石料暗沟”。 1984年对水泥砂土暗管(下称暗管)和 相似文献
9.
暗管排水对油葵地土壤脱盐及水分生产效率的影响 总被引：6，自引：1，他引：5
为了建立宁夏惠农区庙台乡给予太阳能水泵抽水的暗管排水工程的灌溉排水制度,以油葵为研究对象,设暗管排水和非暗管排水2个处理,观测分析了暗管排水对田间土壤含盐量、地下水位和产量等的影响。结果表明,在油葵生育期内,与进行暗管排水前相比,暗管排水使暗管排水区的地下水水位降低0.09 m,降幅6.21%;地下水矿化度降低9.79%;土壤含盐量降低13.64%;与非暗管排水区相比,暗管排水区的油葵增产8.10%,灌溉水生产效率增加8.40%,群体水分生产效率增加9.86%。 相似文献
10.
滴灌条件下暗管滤层结构对排水、排盐效果的影响 总被引：1，自引：1，他引：0
为解决滴灌农田非饱和条件下暗管排水困难的问题,设置2种暗管滤层铺设方式,以常规暗管滤层进行排水为对照,基于室内土槽试验,分析了滤层铺设方式对暗管排水排盐效果的影响及其机理。T1处理为常规暗管滤层铺设方式,暗管四周铺设细砂滤层,T2处理为暗管上部铺设细砂,T3处理为细砂斜垫层斜铺连接体积质量分界层与暗管。结果表明,T1处理受土壤水滞后效应影响显著,暗管不排水,土壤水、盐积聚于暗管底部;T2、T3处理可在暗管上部产生局部饱和区,促使暗管排水。T2处理排水时所需历时较长,排出的水盐总量较少;T3处理可使暗管最早排水,排水时暗管下部土壤积盐最少,排水流量和排水盐总量最大。 相似文献
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This paper describes the essential contents of research at a recently completed subsurface pipe drainage project located in
the Khushab district of Pakistan. The paper explores the need and decision by Government of Pakistan to install a Sub Surface
Pipe Drainage Project near Khushab where an old Surface Drainage System was already installed by the Provincial Irrigation
and Power Department, Government of Punjab, Pakistan, since 1960. The new Sub Surface Pipe Drainage Project’s planning and
executing agency M/S Euro-Consultant used existing Surface Drains with remodeling for to carry the additional drainage effluent
of newly constructed sump pumps of the pipe drainage system connected to the old drains by means of small outfall drains.
Until now the new system is working well in lowering the water table as well as increasing the agro-socio-economic status
of the local population. 相似文献
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M. Rafiq Choudhry Abdul Khaliq W. F. Vlotman Habib-Ur-Rehman 《Irrigation and Drainage Systems》1995,9(1):73-84
Three imported and four local synthetic envelope materials were tested in the laboratory with upward flow permeameters to determine their physical properties and hydraulic performance. The base soil was taken from the site of the Fourth Drainage Project, Faisalabad, Pakistan. The performance parameters included ratios of gradient and hydraulic conductivity of the interface of envelope material and base soil and the discharge through the permeameter, which were evaluated against established particle-retention and filter criteria.The study concluded that each of the tested materials satisfied the particle-retention criteria because the ratio of characteristic diameters of envelope (O90) and soil (d90) remained less than 2.5. The filter criteria, however, could not be met satisfactorily, particularly during receding hydraulic gradients, when the ratio of envelope and base soil hydraulic conductivities (Ke/Ks) dropped below 1, except in the case of one imported material. Blocking of the soil-envelope interface occurred due to the internal movement of soil particles, particularly during receding gradients. 相似文献
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Willem F. Vlotman Shafiq-Ur Rehman Iftekhar Haider 《Irrigation and Drainage Systems》1993,6(4):325-343
In 1989, research on granular envelope design for subsurface horizontal pipe drains was started when existing design procedures for envelope design did not result in successful application of a granular envelope (crushed rock) material at the Fourth Drainage Project. Although construction problems were, in part, the reason for the failure of the crushed rock envelope, it was also found that standard design criteria need additional rules to prevent a similar occurrence of failure. Tests were performed in the laboratory with permeameters, sieves, and other equipment and preliminary results are reported. The effect of number, size and arrangement of perforations on the test results are indicated. Test results of blended granular materials such as crushed rock, river-run gravel and sand from various sources in Pakistan are outlined.Proceedings of 5th International Drainage Workshop, Lahore, Pakistan, ICID-CIID, IWASRI, 1992, Vol. III, 5.38–5.49. 相似文献
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Drainable surplus assessment in irrigated agriculture: field application of the groundwater approach
To assess the drainable surplus of an irrigated area, a methodologybased on a groundwater-balance approach was developed and appliedin Schedule I-B of the Fourth Drainage Project near Faisalabad inPakistan. To determine the seasonal net recharge in this area, anumerical groundwater model was run in inverse mode. The data inputfor the model consisted of the geometry of the aquifer system, theaquifer parameters, and historical watertable elevations. The seasonalnet recharge values, calculated from the individual recharge anddischarge components, were tuned with the results of the inversemodelling. The advantage of such an integrated approach is that allthese components are linked. The design net recharge was estimatedfrom the historical net recharge of the wettest monsoon in the studyperiod. Its rainfall recharge values were then substituted for those of adesign monsoon. In this substitution procedure, the rainfall rechargemethodology and parameters were adopted from the tuning procedure.From this design net recharge, estimates could be made of the requireddrainable surplus, with and without drainage simulation. 相似文献
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侯景伟 《中国农村水利水电》2014,(3):166-168
为了解决灌区水资源配置中的信息采集方法落后和多目标模型求解易陷入局部最优等问题,通过伪随机并行搜索和最近邻域选择等策略对Pareto蚁群算法进行改进,然后将Pareto蚁群算法与3S技术耦合,以宁夏银北灌区为仿真对象,利用改进的Pareto蚁群算法计算灌区多目标、多约束的水资源空间优化配置模型,获得最优的井灌水量、渠灌水量、排水量以及最优的经济效益和灌排费用。基于Pareto蚁群算法和３S技术的灌区水资源空间优化配置,能加快算法的收敛速度,获得全局最优解,使优化结果更接近实际,对灌区的水资源宏观调度具有一定的参考价值。 相似文献
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《Journal of Agricultural Engineering Research》1999,72(1):19-25
Drainage properties of and ammonia emissions from slatted floors and drainage channels were investigated using a laboratory arrangement development for the purpose. The arrangement consists of a steel-framed box with two levels in order to simulate different slatted floor systems. The slatted floor under test is laid on the top level and manure is dropped on to it from various heights. The lower level consists of a drainage channel, the top of which is covered by a lid perforated with holes of different shapes.Drainage experiments on slatted floors for cows with slits from 30 to 45 mm wide showed an average total drainage value for faeces and urine of 72% and an average urine drainage value of 82%. Drainage experiments on slatted floors for pigs showed results varying between 38 and 46% for total drainage depending on different drainage arrangements. The best drainage capacity was obtained when the drainage channel cover had holes giving a large drainage area.The ammonia experiments on slatted floors for cows with 2 and 30 mm spacing showed an accummulated ammonia emission of about 8 and 3 g respectively, during the 20 h testing period. On slatted floors for fattening pigs, the accumulated ammonia emission was calculated to be about 2 g during the 20 h testing period. These ammonia emission results are related to the mass quantities and the nitrogen contents of faeces and urine, which normally are dropped to slatted floor surfaces in animal buildings. 相似文献