ISWC OpenIR  > 水保所知识产出(1956---)
工程堆积体坡面 植物篱 的减流减沙效益 及其机理研究
王 凯
Subtype硕士
Thesis Advisor高照良
2015-05
Degree Grantor中国科学院研究生院
Place of Conferral北京
Keyword工程堆积体 植物篱 冲刷 侵蚀调控 时序特征
Abstract

生产建设项目在施工及生产过程中会产生大量工程堆积体,而堆积体的土壤侵蚀
模数远高于自然坡面,极易产生严重的水土流失,为探索工程堆积体水土保持的有效
措施,本研究利用宽 5m,长 20m 的标准径流小区,通过野外模拟径流试验,在 24°、
28°、32°三种坡度下,采用 35L/min、45 L/min、55L/min 三种放水流量,研究了工程
堆积体坡面应用植物篱措施后的侵蚀过程、减流减沙效益及其侵蚀动力机理,并分析
了其控蚀能力的时序变化。得到了以下结论:
(1)对照小区和植物篱小区的产流量、产沙量都随着小区坡度和放水流量的增
加而增大,植物篱可以有效减少径流量和侵蚀量:①减流效益介于 4%~40%之间,并
随着小区坡度的增加而增大,但与径流流量不是简单的正相关关系,随着流量的增加
先增大后减小。②减沙效益介于 15%~45%之间,随着坡度和放水流量的增加而减小。
(2)对照小区和植物篱小区的产流率、产沙率均随坡度和放水流量的增加而增
大;随冲刷历时的推移,产流率在前期迅速增大而后趋于平稳,产沙率在前期快速上
升,之后明显下降,在大流量(45、55L/min)下,冲刷末段超过了初始时段;植物
篱小区的产流率小于对照小区,且植物篱小区的产流时刻比对照小区要滞后 2~10min,
冲刷后期二者的产沙率逐渐接近甚至前者超过后者。
(3)对照小区和植物篱小区的细沟侵蚀量在区段 1(0~6m)内所占比例最高(≥
40%),随着坡度增加,坡面上部(0~10m)沟蚀量所占的比例呈现先增加后减小的
趋势,随着流量的增加,坡面下部(10~20m)所占的比例随之增大,细沟向下发育
的更加完善。植物篱对坡面下部防护作用较好,将细沟侵蚀限制在上部坡面,且对
24°和 32°坡面的沟蚀分布影响较大。
(4)随着放水流量和坡度的增加,对照小区侵蚀泥沙中砂粒的含量逐渐增加,
黏粒含量减少;相对于对照小区,植物篱可以减弱侵蚀过程中径流对砂粒的剥蚀和搬
运;分形维数可以作为植物篱对侵蚀产沙中泥沙颗粒粒级分布的评价指标。
(5)植物篱将坡面剥蚀率从 3~10g·m -2 ·s -1 降低到 1.5~8g·m -2 ·s -1 ,剪切力从
4~8N·m -2 降低到 2.5~6N·m -2 ,将临界剪切力和临界功率分别提高了 0.25 倍和 5 倍,植物篱通过降低坡面径流能量,削弱径流侵蚀动力,提高坡面的抗侵蚀能力,减小了
水流对坡面的剥蚀程度。
(6)植物篱的控蚀能力随着径流冲刷历时的延长存在临界值,二者之间可用二
次函数进行较好拟合,累积减沙量的最大值出现在冲刷历时 26min 之后,且随坡度和
流量的增加而提前;径流含沙量的时序变化是植物篱控蚀能力存在时间限制的直接原
因;分析实际含沙量与径流挟沙能力变化可以发现植物篱与坡面径流输沙的源~汇关
系,是控蚀能力存在临界值的深层原因。
关键词:工程堆积体,植物篱,冲刷,侵蚀调控,时序特征

Other Abstract

Production and construction projects generate engineering accumulation including
waste dump, gangue field, tailings impoundment during construction and production
process. If soil and water conservation lack, soil erosion on these engineering accumulation
are serious. To explore the effective soil and water conservation measures, standard runoff
plots which are 20 meters long and 5 miters wide were be constructed. Effects and
mechanism of hedgerows on sediment erosion of engineering accumulation was studied by
using runoff scouring experiment under three flow discharges(35, 45, 55L/min) and three
slope gradients(24°, 28°, 32°) . The results indicated that:
(1)Runoff and sediment yield of control plot and hedgerows plot increased with
increasing of runoff discharge and gradient. Runoff yield of hedgerows can reduce runoff
and sediment yield effectively: ①Runoff reduction benefit that reaches 4%~40% increase
with increasing of plot gradient. But the relationship between runoff reduction benefit and
runoff discharge is not simple linear correlativity, it increases first then decreases as
increasing of runoff discharge. ②Sediment reduction benefit of hedgerows which is
15%~45% decreases with increasing of runoff discharge and gradient.
(2)Runoff rate and sediment rate of control plot and hedgerows plot increase with
increasing gradient and runoff discharge. Varying tendency of runoff rate with the time
rapidly increases in early then level off. While sediment rate rapidly increases in early then
dramatic decline in later, even it in the end of the time is less than it in the beginning under
large runoff discharge(45、55L/min). Runoff rate and sediment rate of hedgerows plot is
less than it of control plot. Outflow moment of hedgerows plot is delayed for 2~10min than
control plot. Sediment rate of hedgerows plot is less than it of control plot in early stage,
then the difference is more and more smaller in later stage even the former exceed the later.
(3)Rill erosion amount has the greatest proportion in first section of slope, which is  at least 40%. Rill erosion of the upper slope shows a trend of decrease after the first
increase with increasing of gradient. Rill erosion has the greater proportion with increasing
of runoff discharge, which shows that rill erosion improve downwards. Protective effect of
hedgerows is better for lower slope and rill erosion is limited to upper slope by hedgerows.
Hedgerows have more significant impact on rill distribution of 24° and 32° plot.
(4)The content of sand grains in sediment increase gradually while the content of
clay particles reduce with increasing gradient of and runoff discharge. Compared with
control plot, sand grains content decreases while silt and clay particles content increases in
sediment of Hedgerows plot. This results show that hedgerows have obvious intercept
capability for sand grains. sand grains can be an index to evaluate the effect of hedgerows
to slope erosion.
(5)Hedgerows reduce the soil detachment rate from 3~10g·m -2 ·s -1 to 1.5~8g·m -2 ·s -1 ,
and decrease the runoff shear stress 4~8N·m -2 to 2.5~6N·m -2 , increase critical shear stress
and critical stream power by 0.25 and 5 times. Hedgerows reduce the water erosion
degrees by weaken the energy and erosion dynamic of slope runoff.
(6)Erosion control capacity of a specific hedgerows has a critical value over time.
The relationship between erosion control and scour time can be fit by quadratic function.
The maximum value of sediment reduction accumulated amount appeared later than 26th
min, and it would appear in advance with increasing gradient of and runoff discharge. The
direct cause for time limit of hedgerows controlling erosion is the sequential variation of
the runoff sediment concentration. The ratio of sediment concentration to sediment
carrying capacity show the source-sink relation of hedgerows and runoff which is
underlying cause that erosion control capacity has critical value.
Key words: engineering accumulation; hedgerows; flow discharges; erosion control;
sequential variation

Language中文
Document Type学位论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/9025
Collection水保所知识产出(1956---)
Recommended Citation
GB/T 7714
王 凯. 工程堆积体坡面 植物篱 的减流减沙效益 及其机理研究[D]. 北京. 中国科学院研究生院,2015.
Files in This Item:
File Name/Size DocType Version Access License
工程堆积体坡面 植物篱 的减流减沙效益及(1660KB)学位论文 开放获取CC BY-NC-SAApplication Full Text
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[王 凯]'s Articles
Baidu academic
Similar articles in Baidu academic
[王 凯]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[王 凯]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.
 

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.