| 引用本文: | 李超,于健,李伟帅,等.扬水灌区渠道泥沙冲淤时空分布特性及临界条件[J].灌溉排水学报,0,():-. |
| LI Chao,YU Jian,LI Weishuai,et al.扬水灌区渠道泥沙冲淤时空分布特性及临界条件[J].灌溉排水学报,0,():-. |
|
| 摘要: |
| 【目的】探究镫口扬水灌区总干渠泥沙淤积特性、影响因素及冲淤平衡的渠道边界和临界水力条件。【方法】对2010-2012年各灌水期总干渠不同监测断面进行水样采集及水力特性量测，分析泥沙颗粒级配、含沙量、泥沙来源、渠道冲淤时空特征。计算不同流量下各监测断面的水流挟沙力，对比现状渠道和渠道整治后水流挟沙力与实测含沙量大小关系。【结果】①造成总干渠淤积的泥沙主要为粒径大于75 μm的推移质泥沙，泥沙来源包括水中悬移泥沙和停泵后淤积在取水口周围泥沙。②泥沙淤积主要发生在总干渠上游泵站出水口-东富桥断面之间，各灌水期中夏灌二水淤积量严重。③现状渠道在流量小于30 m3/s时水流挟沙力明显小于含沙量，导致总干渠整体处于淤积状态。④增大渠道底坡坡降至1/7000，结合渠道整治与衬砌，可以显著提高水流挟沙力，根据挟沙力计算和输沙效率指标综合分析总干渠多年平均含沙量下不淤临界流量为24 m3/s。【结论】研究确定的不同引水来沙条件下的冲淤平衡矩阵及临界流量可以用于指导灌区渠道防淤管理。 |
| 关键词: 扬水灌区;泥沙;冲淤;挟沙力;临界流量 |
| DOI： |
| 分类号:S274.3 |
| 基金项目:冰-水-堤互馈机制下堤岸崩塌失稳机理及模式研究 |
|
| Study on Spatial-Temporal Distribution Characteristics and Critical Conditions of Channel Sediment Erosion-Deposition in Pumping Irrigation District |
|
LI Chao1, YU Jian2, LI Weishuai2, LI Quan3
|
|
1.College of Water Resources and Civil Engineering,Inner Mongolia Agricultural University;2.Water Resources Research Institute of Inner Mongolia;3.Inner Mongolia Autonomous Region Dengkou Pumping Irrigation District Administration
|
| Abstract: |
| The purpose of this paper is to study the sediment erosion-deposition characteristics, influence factors and channel boundary and critical hydraulic condition for fluvial equilibrium in Pumping Irrigation District. 【Method】Water sampling and hydraulic characteristics was collected and measured at different monitoring section during each irrigation period from 2010 to 2012 year to analyze the sediment gradation of grain, concentration, source and spatial-temporal distribution characteristics. The sediment carrying capacity at different discharge was calculated, Which is used to determine the relationship between sediment carrying capacity and measured concentration under current situation and improved channel. 【Result】① Channel deposition is mainly caused by the bed load with grain size greater than 75 μm , which is formed from suspended load and deposition sediment around intake after stop pumping. ②Sediment deposition appeared at water outlets of Pump station in channel upstream on the Dongfuqiao section. And the second summer irrigation would cause serious sendimentation. ③Sediment carrying capacity of current channel under discharge of water less than 30m3/s is lower than sediment concentration, which lead to sediment deposition of the whole channel. ④Combined with channel improvement, increasing bed slope to 1/7000 can increased sediment carrying capacity significantly. The non-silting critical discharge is 24 m3/s base on comprehensively analyzing of sediment carrying capacity and transport efficiency index. 【Conclusion】Fluvial equilibrium matrix and critical discharge for different sediment concentration can be used to direct the management of prevention deposition in pumping irrigation district. |
| Key words: pumping irrigation district; sediment; erosion-deposition; sediment carrying capacity; critical discharge |
