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小开河灌区水沙分布及泥沙长距离输送机理研究 总被引:1,自引:0,他引:1
小开河灌区是黄河下游20世纪末扩建改造的大型引黄灌区,经输沙渠把泥沙进行长距离输送,在远离黄河大堤51.3km处修建沉沙池集中处理泥沙.1998年11月通水试运行,2001年底正式运行,工程建成后,输送入沉沙池泥沙占引黄闸进沙量的52.13%,实现了泥沙长距离输送的目标.本文首先介绍了小开河灌区工程建设及运行情况,10年来灌区水沙分布,针对泥沙长距离输送机理问题,研究分析了小开河灌区渠道特性、长距离输送特点和输沙渠冲淤规律,提出输沙渠泥沙垫底淤积量概念和基本冲淤平衡水沙条件. 相似文献
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依据小开河灌区运行10 a来的资料,总结灌区引水引沙条件和渠道断面特性,研究干渠不同渠段的引水分布特征和泥沙长距离输送、淤积特性。根据断面实测流量资料,给出输沙渠不同渠段的河宽、水深、流速、水力半径等水力参数与流量关系的水力几何形态指标,进而得出小开河灌区不同渠段的水流挟沙力与流量的关系。计算结果表明,设计流量下小开河灌区输沙渠沿程输沙能力变化不大,输沙渠中段由于渠道宽度较大,相同流量条件下的输沙能力较上、下段偏小约2 kg/m3。 相似文献
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引黄灌区水沙资源配置技术的研究 总被引:2,自引:0,他引:2
引黄灌区水沙资源配置关键技术包括灌区减沙沉沙技术、引水分沙技术、渠道输水输沙技术等。通过引黄灌区引沙和沉沙资料的分析,总结了灌区减沙技术和有害泥沙拦沉技术,减沙主要是通过控制引水含沙量或减少引水量来实现,有害泥沙的拦沉主要是利用渠道拦沙设施和沉沙池拦截和沉积有害的粗颗粒泥沙。结合渠道输水输沙能力,分析了提高灌渠输沙能力的工程措施和非工程措施,工程措施包括加大渠道比降、渠道衬砌、改造阻水建筑物、优化断面等,非工程措施主要是指水沙调控技术。通过分析渠道引水分沙特征,进一步探讨了引黄灌区自流灌溉和提水灌溉的特点,指出自流灌溉的支渠引水含沙量略低于或等于干渠含水量;若提水泵站进口合理布置在平均含沙量水深以下,将会有利于渠道减淤。 相似文献
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引黄灌区水沙资源配置关键技术包括灌区减沙沉沙技术、引水分沙技术、渠道输水输沙技术等。通过引黄灌区引沙和沉沙资料的分析,论述了引黄灌区减沙技术和对灌区有害的粗颗粒泥沙处理技术,前者主要是通过控制引水含沙量或减少引水量来实现,后者主要是通过有害泥沙的拦截和沉积来达到。结合渠道输水输沙能力,总结了提高灌渠输沙能力的工程措施和非工程措施,前者包括加大渠道比降、渠道衬砌、改造阻水建筑物、优化断面等,后者主要是指水沙调控技术。通过分析渠道引水分沙特征,进一步探讨了引黄灌区自流灌溉和提水灌溉的特点,指出自流灌溉的支渠引水含沙量略低于或等于干渠含水量,渠道处于增淤状态;若提水泵站及其进口合理布置,将会有利于渠道减淤。 相似文献
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渠道不同粒径组泥沙的输移特性 总被引:5,自引:0,他引:5
本以灌区实测水沙资料为基础.通过分析悬沙垂线分布,提出泥沙输送的条件,进一步分析不同粒径组泥沙的输移特性及对渠道泥沙淤积的影响。指出粗沙是造成泥沙淤积的关键.阐述不同粒径组泥沙都具有多来多排的特性.但其变化规律有所差异。通过比较多十挟沙能力公式.最后给出适应簸箕李灌区挟沙能力的具体表达式。 相似文献
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黄河下游灌渠水流泥沙数学模型 总被引:2,自引:1,他引:1
本文结合灌渠的结构特点及水流泥沙特性,对一维非耦合,非均匀、不平衡沙基本方程组进行了合理的简化,根据实体模型试验实测资料,确定了自流与提灌时干,支渠分流的不同分沙分水比。 相似文献
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目前,引黄灌区渠道集中处理泥沙的模式已受到很大的限制,进一步研究分散处理泥沙的模式是非常必要的。本文在山东簸箕李灌区的基础上,分析水沙资料,总结灌区泥沙输送的经验。 相似文献
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近50年来长江中游泥沙输移变化 总被引:4,自引:3,他引:1
对1950年以来长江中游泥沙输移资料作了初步分析。分析结果表明:20世纪60年代下荆江裁弯后,三口(松滋口、太平口、藕池口)分流分沙减少,下荆江径流量和输沙量相应增加,洞庭湖泥沙淤积减少;80年代中期以后,长江中游干流及洞庭湖出口的年输沙量呈减少趋势,城陵矶至武汉河段河床由淤积转为趋向冲淤平衡三峡工程初期蓄水运用后,长江中游含沙量沿程恢复距离较长,但床沙质部分恢复距离相对较短。 相似文献
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泥沙问题是制约引黄灌区可持续发展的重要因素,灌渠的规划设计阶段和日常的运行管理中都需要掌握渠道的泥沙冲淤情况。本文根据一维水流非均匀沙运动方程,结合灌区灌溉特点和测量资料情况作了概化处理,建立了适合于灌区的非均匀沙冲淤计算的数学模型。模型中考虑渠系沿程的分水分沙和冲淤交换,将断面流量按渠段划分并计算,悬移质泥沙按粒径分组计算,根据分组水流挟沙力和非均匀悬移质不平衡输沙公式计算泥沙含沙量。模型采用山东簸箕李灌区的实测资料进行验证,表明模型可用于预测不同来水来沙条件下非均匀沙在渠道内的运动淤积分布情况。 相似文献
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Marala Barrage was constructed in 1968 on River Chenab as a replacement of old Marala weir, which was constructed in 1912. Two canals, Marala Ravi Link (MRL) Canal and Upper Chenab Canal (UCC) off-take from left side of the barrage. It has an old history of varying sediment problems in both of these canals. Several attempts were made to investigate the problems and suggest remedial measures in the past and some of them were partially implemented as well. This paper reviews the major sediment management problems at Marala Barrage and their possible causes. The previous interventions are critically examined for their suitability and effectiveness in general and the effect of raising crest of MR Link canal in particular. The paper concludes that some of the past interventions have a positive effect on silt control entry in the off-taking canals. The analysis of data regarding sediment entry at the head of the canals indicate that the raising of crest of MR Link in the year 2000–2001 has improved the sediment intake in this canal to some extent, but its effect on the UCC is almost negligible. The data regarding sediment entry at the head of the UCC which had a scouring tendency, does not show any significant effect of this intervention as was perceived at the implementation stage. However, it is worth mentioning that analysis of data related to cross-sections and L-sections of the head reaches of these canals show a different trend, which makes it difficult to assess the long term and sustainable effect of this intervention on both of the canals. A critical review of data collection process and effective monitoring of the system is compulsory for meaningful analysis and future course of action if the present tendency seems to be changing, the possibility of which does exist. 相似文献
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Equilibrium sediment transport in lower Yellow River during later sediment-retaining period of Xiaolangdi Reservoir 总被引:1,自引:0,他引:1
The Xiaolangdi Reservoir has entered the later sediment-retaining period, and new sediment transport phenomena and channel re-establishing behaviors are appearing. A physical model test was used to forecast the scouring and silting trends of the lower Yellow River. Based on water and sediment data from the lower Yellow River during the period from 1960 to 2012, and using a statistical method, this paper analyzed the sediment transport in sediment-laden flows with different discharges and sediment concentrations in the lower Yellow River. The results show that rational water-sediment regulation is necessary to avoid silting in the later sediment-retaining period. The combination of3 000 m3/s < Q < 4 000 m3/s and 20 kg/m3< S < 60 kg/m3(where Q is the discharge and S is the sediment concentration) at the Huayuankou section is considered an optimal combination for equilibrium sediment transport in the lower Yellow River over a long period of time. 相似文献
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底栏栅引水枢纽具有结构简单、施工方便及造价低廉等优点,在我国应用较广。采用这种枢纽方式引取的水流中含沙量小,能有效地解决下游渠道泥沙淤积严重的问题。阜康市三工河渠首采用该型式,基本解决了大量泥沙入渠的问题,并在1 a的运行中取得了非常好的引水排沙效果。 相似文献