ISWC OpenIR  > 水保所知识产出(1956---)
集中流作用下黄土坡面剥蚀率对侵蚀动力学参数的响应
肖海1; 刘刚1,2; 刘普灵1,2
2016
Source Publication农业工程学报
Volume32Issue:17Pages:106-111
Abstract

集中流引起的细沟侵蚀是黄土高原坡耕地主要侵蚀方式之一,对坡面集中水流动力学特性研究有利于掌握坡面
集中流剥蚀产沙的根本原因,但目前哪种集中流水动力学参数最能准确揭示侵蚀动力过程机理尚不明确。该文采用室内
集中流放水冲刷试验,以黄土高原典型黄绵土为研究对象,研究坡面平均和瞬时剥蚀率与相应水流剪切力、水流功率、
单位水流功率以及过水断面单位能量之间的关系。结果表明,除了瞬时过水断面单位能量拟合效果较差外,其他平均和
瞬时水力学参数均能够较好地与坡面剥蚀率建立不同的拟合关系。所有参数中平均水流功率是描述本试验条件下的最优
水力学参数。由于细沟发育过程中大量坍塌的出现,导致整个径流剪切力和水流功率与剥蚀率之间的关系曲线整体上升,
出现了临界剪切力和临界水流功率为负值的情况。通过与仅考虑水流对坡面直接作用参数所得结果对比,表明坍塌等作
用在细沟发育过程中具有重要影响,对剥蚀率的贡献可达90.93%。研究可为控制和预防集中流侵蚀发生提供科学依据。

Other Abstract

Rill erosion caused by concentrate flow is one of the main erosion types on cultivated slope in the Loess Plateau. It
is necessary to research on the response of concentrate flow hydrodynamic characteristics for a better understanding of rill
erosion mechanism. However, the optimal runoff hydrodynamic parameter for estimating detachment rate was still ambiguous.
An indoor concentrate scouring experiment was carried out was carried out in the State Key Laboratory of Soil Erosion and
Dryland arming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of
Water Resources, China to investigate the response of runoff hydrodynamic characteristics to detachment rate under
concentrate flow condition with different inflow rates and slope gradients. Loessal soil collected from Yanan (35°21′-37°31′ N
and 107°41′-110°31′ E) in Shaanxi province, a kind of typical soil in the Loess Plateau, was prepared for this research. The
experiments were applied to a soil plot with 5 m long, 1 m wide and 0.5 m deep. Packing was carried out layer by layer to
attain the desired uniform bulk density (about 1.25 g/cm-3) with 40 cm in depth. The bottoms of the boxes were perforated and
covered with a layer of 10 cm sand under the gauze to facilitate even drainage of percolating soil water. After packing, the soil
was watered to saturation with an electric sprayer to reduce the variability caused by packing. Four flow rate (10, 15, 20 and 25
L/min) combined with four slope gradient (10°, 15°, 20° and 25°) were designed for this research. The experiment lasted for 10
min after runoff initiation. Runoff and sediments were collected in a series of plastic containers at intervals of 1 min
throughout the 10 min. The volume of water in each container was measured, and the sediment was dried in an oven and
weighed. The flow velocity was measured by dye-tracing technique within the 1-4 m away from the bottom and the flow width
was also measured at 4 sections between 0.5-4.5 m to estimate flow depth at every minute during the experiment. The relations
between runoff hydrodynamic characteristics, including shear stress, stream power, unit stream power and unit energy of
water-carrying section, and detachment rate were analyzed. The results showed that all the mean and instantaneous runoff
hydrodynamic characteristics factors fitted the detachment rate well with different regressions equations except instantaneous
unit energy of water-carrying section. The mean runoff hydrodynamic characteristics factors were better than those of average
values for fitting with detachment rate. The optimal runoff hydrodynamic characteristics factor in our research was mean
stream power because it was of the largest determination coefficient 0.97. The curve of linear regressions of mean shear stress
and stream power with detachment rate became ascended because of collapse during the experiment process, which also led to
a negative value for corresponding critical shear stress and stream power. By comparing results with that from a published
paper that only considered the flow effect on soil surface in the same soil, the detachment rate directly estimated based on
mean stream power were more reasonable than those estimated based on mean shear stress. The collapse could account for
90.93% of the detachment rate, indicating an important role of collapse during rill development process. The results provide
valuable information for a better understand of the response of concentrate flow hydrodynamic characteristic factors to
detachment rate and its corresponding erosion mechanism.

Keyword水动力学 径流 剪切力 集中流 土壤剥蚀率 坍塌作用
Indexed By中文核心期刊要目总览
Language中文
Document Type期刊论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/8630
Collection水保所知识产出(1956---)
Affiliation1.西北农林科技大学水土保持研究所,黄土高原土壤侵蚀与旱地农业国家重点实验室
2.中国科学院水利部水土保持研究所
Recommended Citation
GB/T 7714
肖海,刘刚,刘普灵. 集中流作用下黄土坡面剥蚀率对侵蚀动力学参数的响应[J]. 农业工程学报,2016,32(17):106-111.
APA 肖海,刘刚,&刘普灵.(2016).集中流作用下黄土坡面剥蚀率对侵蚀动力学参数的响应.农业工程学报,32(17),106-111.
MLA 肖海,et al."集中流作用下黄土坡面剥蚀率对侵蚀动力学参数的响应".农业工程学报 32.17(2016):106-111.
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