都江堰工程运行两千余年的科学原理

来源 :2010中国可再生能源科技发展大会 | 被引量 : 0次 | 上传用户:zhaokfq
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  都江堰工程成功运行两千余年,至今仍发挥着重要的灌溉引水与防洪作用,堪称水利工程史上的奇迹。从都江堰工程的地理位置和工程布局、水沙控制原理以及工程的维护与变迁角度,对都江堰工程经久不衰的科学原理进行了研究总结。都江堰工程利用地形地势和工程调节,分两级实现分流排沙功能,完成引水与防洪的任务。第一级分流排沙主要受关口至鱼嘴河段洪、枯水主流线摆动和弯道环流的控制,实现了水分四六和弯道排沙的效果。第二级分流排沙主要受内江弯道环流和飞沙堰、宝瓶口联合作用的控制,利用内江的弯道环流,使表层水流进入宝瓶口,而下层的卵石和泥沙从飞沙堰排出。在洪水时由于宝瓶口口门窄深,外加横向射流压缩了有效过水面积,使洪水通过宽浅的飞沙堰和人字堤排入外江,保障灌区防洪安全。两千多年来都江堰工程经历多次变革维修,而正因为遵循了河流水沙运动的自然规律,通过反复实践检验,才使得这一伟大工程长盛不衰。
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