共查询到20条相似文献，搜索用时 15 毫秒
1.
长距离引调水工程是实现水资源优化配置的重要手段,特别是在西部地区其具有规模大、隧洞占比高、地质条件复杂和线路长、建设周期长、项目类型多等特点,工程质量管理与控制难度大。以云南滇中引水工程为依托,分析当前西南地区长距离引调水工程质量管理中的问题和难点,研究加强质量管理和控制的措施,提出了“1+3”监管模式等质量管控对策,取得了良好效果。 相似文献
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20世纪80年代末,新疆叶尔羌河流域上的卡群引水枢纽、勿甫龙口、民生渠首等水利工程的先后建成并运用,极大改善了叶尔羌河水利管理条件,但也引起河道流量发生了一些变化,影响到卡群站以下各水文站洪水资料系列的一致性。为推求下游各防洪工程控制节点的设计洪峰流量,根据各水文站之间的引、退水渠引、退水资料计算相对衰减率,对叶尔羌河流域出山口以下水文站实测洪峰流量进行了还原计算,推求设计洪峰流量。 相似文献
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Hans Charles Komakech Marloes L. MulPieter van der Zaag Filbert B.R. Rwehumbiza 《Agricultural Water Management》2011,98(11):1719-1726
Although spate irrigation systems are risk-prone, they can be an important component for livelihood security in semi-arid areas. Spate uses water (flood water), which upstream users often do not require, as rainfall during these periods is more than sufficient. The use of this flood water for spate irrigation is therefore a good opportunity to convert water with a low opportunity cost to high value water. As more rivers are closing, due to socio-economic and climate changes, spate irrigation may become increasingly relevant in semi-arid areas. Spate irrigation systems pose institutional and technical challenges: collective action is challenged by complex upstream-downstream interactions between users within the system, and the high labour demands for regular reconstruction of temporary diversion weirs and intake structures. This paper describes a spate irrigation system in Makanya village, Tanzania that emerged in response to increased upstream water use. We use three of the four dimensions (hydrological, hydraulic and sociological) of spate irrigation proposed by Van Steenbergen (1997) to assess the Makanya spate irrigation system. The Makanya spate irrigation system has an organisational structure that is similar to the canal irrigation (furrow) committees located upstream, and effectively deals with the institutional demands of managing water in spate irrigation systems. Water allocation is reminiscent to the water sharing arrangements existing in the full irrigation system, which previously was in place at the site and in the high- and midlands of the Makanya catchment and therefore set this system apart from the traditional spate irrigation practice elsewhere. Technically, a major challenge is the reconstruction of the head works after each flood. Another aspect is the changes in the river bed. Flash floods carry sediments that deposit on the fields, raising the elevation of the irrigated land every year and making it increasingly difficult for the river water to enter the plots. Improving system efficiency through modernisation of the diversion and distribution structures in this case is not feasible due to the huge amounts of sediments delivered to the system each year. Instead investments in conjunctive use of groundwater could be the solution because it involves a relatively small intervention, minimises the physical disturbance of the system, and therefore is likely to respect the existing locally developed water management arrangements. 相似文献
4.
范春萌 《国际沙棘研究与开发》2017,(5)
河道是城市生存发展的重要资源,彻底改善水质、增强河道防洪能力、促进水系的循环、解决河道现状问题是城市建设中较为重要的部分.本文以大凌河为例,设计了四种景观方案,利用物理实验和数值模拟等研究手段,通过流体动力学、计算机数值分析等技术,将植被群及景观岛高度作为水流的主要影响要素进行研究,并对洪水来袭时不同的生态景观方案下河道的水位和流速进行模拟,进而定性分析不同城市生态景观对防洪的影响.该研究对景观防洪的实际应用有着非常重要的现实意义. 相似文献
5.
结合长江流域防洪规划，介绍了湖北省长江防洪规划，包括防洪标准及防洪体系等，分析了三峡工程建设前的湖北省长江防洪形势、当前（2007年）三峡工程对湖北省长江段的防洪作用以及三峡工程建成后湖北省长江防洪形势，在此基础上着重阐述了对三峡工程建成后湖北省长江防洪值得关注的荆江河势控制、城陵矶防洪控制水位及超额洪量转移问题的认识，并提出了建议。 相似文献
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Agricultural land use and flood risk management: Engaging with stakeholders in North Yorkshire 总被引：1，自引：0，他引：1
Recent changes in agricultural and flood defence policies create new opportunities for involving rural land use, in particular agriculture, in flood risk management. This paper presents the results of a case study on land management and flooding in the Laver and Skell catchments in North Yorkshire. The perceptions of local stakeholders were explored through interviews with farmers and discussions among stakeholders that were held, supported by the Floods and Agriculture Risk Matrix (FARM) tool, during a stakeholder workshop. These stakeholder perceptions are reviewed against scientific evidence. Temporary storage of runoff water on farmland was found to have potential to mitigate flooding, but the participating stakeholders thought that this was beyond farmers’ responsibility of good farming practice. During the stakeholder workshop, it was therefore agreed among all participants that targeting funding is needed, as well as stakeholder engagement and demonstration farms, in order to successfully involve farmers in flood risk management. 相似文献
8.
《Agricultural Water Management》1998,38(1):33-44
A computer program model for pricing irrigation water among beneficiaries was developed and tested. The data used for the purpose was collected from Lower Moshi farmer-managed irrigation scheme (FMIS) in northern part of Tanzania as a case study. The scheme has two intakes; namely Rau and Mabogini irrigation systems. Allam's mathematical model for allocating irrigation water price which was developed in Egypt (Allam, 1987) was adopted and adapted for the purpose. The results indicate that the irrigation water price depends on a number of structures serving the area, their installation costs, amount of water received by each tertiary block and water rights. The prices differ between different tertiary blocks within the same system and also between two systems that exist in Lower Moshi Irrigation Scheme (LMIS). This indicates that the model can be used as a tool by designers and planners for selecting the best designed irrigation system that farmers can afford to pay for its operation, maintenance and management. The mean irrigation water price value for Mabogini is Tshs. 12 151/-1 while that of the Rau system is 10 414/-. To maintain uniformity of irrigation water price in the scheme, it is recommended that a mean value of Tshs. 11 283/- is used. Generally, farmers in Tanzania are used to contribute one bag of paddy which costs about Tshs. 10 000/- for maintenance works. Therefore, the irrigation water price derived from the model is reasonable and one the farmers can afford. 相似文献
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针对引汉济渭工程重要调蓄枢纽三河口水库洪水资源利用实际问题开展研究,采用分形理论汛期分期方法对三河口水库汛期进行分期,并进行相应洪水资源调度模拟分析,以期充分利用三河口水库洪水资源。基于分形理论得到三河口水库的汛期分期结果为:6月1日至6月30日为前汛期,7月1日至9月30日为主汛期;在分期汛限水位基础上,基于1954年7月至2008年6月共55年的长系列径流资料,拟定了洪水资源优化调度方式,进行多元化洪水资源化调度模拟计算,结果表明:在考虑分期汛限水位后进行水库调度运行,将增加供水与发电效益,同时对下游河道生态供水满足程度有较大提高。本文结果表明分形理论可满足三河口水库洪水分期需要,可作为进行水库洪水资源利用的有效途径。 相似文献
11.
引江济汉工程中引水渠道内泥沙淤 总被引：1，自引：0，他引：1
根据引江济汉工程渠道引水防沙的设计要求，在收集基本水文泥沙和工程基础资料的基础上，运用一维恒定流非均匀沙数学模型，研究了不设沉沙池和设沉沙池后引水渠道内泥沙淤积情况，模型计算结果可以为引江济汉工程中渠道引水防沙设计提供依据。 相似文献
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杜晓宁 《农业机械化与电气化》2014,(4):52-53
河砂是缓冲河道水流、涵养水源、保护堤防与河岸的重要资源。目前河砂无序开采情况日益严重,造成河砂资源浪费与河道行洪安全隐患。阐述河砂滥采乱挖的危害与治理经验,提出河道采砂管理建议,以加强资源保护,维护河道行洪安全。 相似文献
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《Agricultural Water Management》2001,48(1):51-60
Eritrea’s coastal zone has been identified as an area of substantial development potential. About 14,000 ha of this 5 million ha area (i.e. <0.3%) has already been developed under a form of spate irrigation known locally as jeriff. This is a water diversion and spreading technique in which wadis (ephemeral streams), springing from Eritrea’s Central Highlands are diverted to irrigate land in the coastal plains. The system as it is applied in Sheeb, an area north-east of Asmara, characterised by agro-pastoral spate irrigation, is described. Under spate irrigation, crop growth is entirely dependent on the residual soil moisture stored in the soil profile. If the basin fields are flooded adequately, the resulting residual soil moisture is sufficient for two or sometimes three crop harvests. The spate irrigation system builds up land by depositing rich sediment on the fields, but therefore, the elevation of the irrigated lands rises every year. Moreover, the system requires huge numbers of trees annually for constructing diversion structures which are subsequently often washed away by heavy floods. In general, the overall irrigation efficiencies of spate schemes are only about 20% because of the difficulty of controlling floods and because water is lost by percolation, seepage and evaporation. Suggestions are made to improve the system and make it more sustainable: permanent flood diversion and distribution structures should be built to effectively divert the floods and to reduce water loss through percolation and seepage, and the basin fields should be properly levelled to distribute the floodwater uniformly over the entire field. 相似文献
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从水库、分蓄洪区及河道调蓄洪的基本原理出发，建立了一个复杂防洪系统的大规模线性规划（ＬＰ）模型。针对隐含着０～１要素、难以拟线性化的扒口分洪问题，提出了判断扒口分洪界点及其相应的分阶段算法的处理方法。实例验算表明，该分阶段算法是可行的。 相似文献
15.
随着我国许多流域防洪体系建设的逐渐完善和水利部门防洪思路的逐渐改变，对流域防洪系统进行综合评价显得很有必要，而要进行防洪系统综合评价首先要建立评价指标体系。阐述了社会系统、经济系统和防洪系统之间的既相互制约又相互促进的关系，说明三者处于一种动态的协调平衡中；结合三者之间的关系，从辽河流域实际情况出发，考虑资料收集的可行性，以全面而精练为准则，分别建立了社会系统、经济系统和防洪系统指标体系，以期对辽河流域防洪系统进行全面、客观的科学评价。该指标体系结合实际作适当修改可以应用于其他流域的防洪系统评价中。 相似文献
16.
Mahmoud M. Moustafa 《Irrigation and Drainage Systems》2004,18(2):109-125
The Government of Egypt is mandated toplan, construct, operate, manage, andmaintain the water system. However, withthe growing water demands over supplies inthe country, water management became a verydifficult task. This has led Egypt toreform policies, technologies,institutions, and development strategies tomanage water more effectively. One of thesestrategies is the irrigation managementtransfer (IMT) that has been a majorstrategy adopted to encourage farmers toplay a more important role in irrigationmanagement and related water services andalso share the cost of O&M of irrigationand drainage systems. IMT policy islaunched in Egypt as a pilot phase toexpand water users' participation atsecondary levels of the irrigation anddrainage systems. Four pilot areas (5,000–8,000 acre) representing all categories andgeographical locations of agriculturallands of Egypt were selected to implementthis policy.This study was conducted in these pilotareas prior to the start of any IMTactivities to describe, analyze, andexplain farmers' attitudes towardirrigation maintenance and implementationof IMT process. Socio-economicquestionnaires were designed and used asthe main tool for data collection. Afterthe field pre-test of the surveyinstrument, a sample of 240 farmers, 60from each pilot area, was selected usingthe sampling frame of multi-tiered process,and the statistical data analysis was doneusing SpssWin software.The major result of this study is that,without proper education and interface withfarmers, there is widespread resistance tothe idea farmers assuming management andmaintenance responsibilities beyond theon-farm level. It would have to proceedvery cautiously, and yield responsiveresults if it were to survive in the faceof the attitudes the farmers have shown,with their strong belief in the necessityof the role of the government. Meanwhile,farmers expressed great confidence in theIMT process and its objectives. 相似文献
17.
黄河河龙区间洪水泥沙关系分析 总被引：1，自引：0，他引：1
《灌溉排水学报》2019,(Z1)
【目的】深入了解近年来黄河泥沙变化规律,保障引黄工程的安全运行。【方法】对2006—2015年黄河吴堡、龙门水文站洪水特征资料进行了分析研究,【结果】月最大含沙量大于10 kg/m~3时段集中在3月桃花汛和汛期(6—9月),汛期泥沙量远大于3月水平,同期龙门站最大含沙量水平高于吴堡站;洪水过程径流总量与含沙量相关性并不显著;河龙区间上下游泥沙输移过程存在一定相关性,但龙门站较吴堡站更多呈现自然河道属性。【结论】黄河突发增沙原因不只局限于洪水激增,黄河调水调沙等人类活动对水流携沙突增影响不容忽视。不同水文站局部性暴雨所形成的短历时增沙现象的水文系列过程呈现随机性。 相似文献
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灌溉模式多是井渠双配套,导致工程重叠,土地占压多,引沙量大,且浪费有限的水资源。为实行开源节流,地表水与地下水联合应用,在引黄灌区部分区域开展纯井灌溉是非常必要的。茌平县阁三里位于位山引黄灌区中游,周围引黄条件好,却一直利用地下水实行纯井灌溉。该井灌区(以下简称试区)拥有丰富的地下水动态及水文地质资料,开展阁三里纯井灌水均衡及效益研究,对于指导当前水资源合理调度及工程规划具有重要意义。该文通过系统地分析研究,证明在引黄灌区内部分区域开展纯井灌是必要的、合理的、成功的。 相似文献
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The paper reports research on engineering designs of irrigation systems in mountainous areas and the resulting implications for management. The engineering designs are important because they may or may not provide the social basis for local people to participate in system development and management. This hypothesis is analyzed by using field data from an irrigation development program in the Himachal Pradesh State in India. The development program will construct about 150 small-scale, gravity flow and lift irrigation schemes in a seven year period. The results of the analysis support the argument that the engineering designs critically influence local people's capability and willingness to manage irrigation facilities. In gravity flow irrigation schemes, water capture by permanent flow diversion structuress is extremely expensive and yet unreliable because of large variation in stream flow and unstable mountain slopes. A more practical alternative is to utilize diversion structures of temporary nature which are made with local materials. Construction and management of such structures will encourage local participation because of high maintenance requirements. In lift irrigation schemes a conventional design is to lift all water requirements to a single highest point in the command area. This practice results in unnecessarily high energy costs and in a water distribution system which is complex to manage. A better alternative is to design the pumps so that water can be delivered at variable elevations in the scheme area. This will allow disaggregation of the total area into smaller rotational units and, therefore, management of water distribution can be potentially easier and equitable. 相似文献