QQ客服 官方微博 反馈留言

	卵砾石淤积的沙洲发育机理
	李志威 ; 王兆印 ; 余国安 ; LI Zhiwei ; WANG Zhaoyin ; YU Guoan
	2016-03-30 ; 2016-03-30
关键词	河流动力学 沙洲发育 最小阻力原理 推移质 淤积 river dynamics bar development least resistance principle bed load deposition TV147
其他题名	Development mechanism of gravel-cobble bars
中文摘要	卵砾石的沙洲在山区河流的局部河段广泛发育。通过对沙洲平面形态的概化,推导菱形沙洲的沿程水头损失表达式。依据最小阻力原理,沙洲只有通过洲头淤积向上游生长的发育模式才能实现其沿程阻力达到最小。卵砾石淤积的沙洲洲头浅滩、边滩和洲尾浅滩的边坡泥沙颗粒临界起动的受力分析可知,洲头浅滩的推移质处在逆坡中最难起动,洲尾浅滩处在顺坡次之,两侧边滩沿水流方向最易起动,故洲头相对于洲尾更易于推移质停留与淤积。植被发育可促进沙洲前期发育和后期稳定,洲头一般堆积卵砾石的浅滩,洲头中部为草本植物,洲尾为灌木林覆盖,沙洲洲面的不同植被覆盖情况不仅揭示沙洲植被演替规律,而且验证沙洲向上游生长的发育模式。; Gravel-cobble bars often develop in local reaches of mountain rivers. Gravel-cobble bar is generalized with a diamond shape and an expression of frictional head loss along the course is derived. By the least resistance principle, a gravel-cobble bar must be in headward aggradation and grows upstream to achieve the least resistance along the course. An analysis on the critical incipient motion of grain particles on the slopes of the bar's head, tail and two sides indicates that sediment particles on the upward head slope are the most difficult to reach incipient motion, second on the downward tail slope, and last along the lateral slopes. Bedload particles are easier to stay and deposit on the bar head than bar tail. Vegetation growth can favor the early development and subsequent stabilization of gravel-cobble bars. A stable bar is generally covered with dense vegetation, where trees and shrubs often develops on bar tail and herbaceous vegetation on middle bar body, and pebble bar or some anti-flooding herbs often appear on bar head. Differences in vegetation coverage of bar surface not only suggest the processes of vegetation succession, but verify the development patterns of bar growing upstream.
语种	中文 ; 中文
内容类型	期刊论文
源URL	[http://ir.lib.tsinghua.edu.cn/ir/item.do?handle=123456789/148719]
专题	清华大学
推荐引用方式 GB/T 7714	李志威,王兆印,余国安,等. 卵砾石淤积的沙洲发育机理[J],2016, 2016.
APA	李志威,王兆印,余国安,LI Zhiwei,WANG Zhaoyin,&YU Guoan.(2016).卵砾石淤积的沙洲发育机理..
MLA	李志威,et al."卵砾石淤积的沙洲发育机理".(2016).

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。