Influencing factor analysis of rill erosion section morphology development on slope and its dynamic characteristic experiment

被引：0
|
作者：
Ma X. [1 ]
Zhang K. [1 ,2 ]
Yang F. [1 ]
Yang M. [2 ]
Dong X. [1 ]
机构：
[1] College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling
[2] State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling
来源：
Zhang, Kuandi (zhangkuandi428@126.com) | 1600年 / Chinese Society of Agricultural Engineering卷 / 33期
关键词：
Drop pit; Energy dissipation efficiency; Erosion; Experiment; Form index coefficient; Rill morphology; Soils;
D O I：
10.11975/j.issn.1002-6819.2017.04.029
中图分类号：
学科分类号：
摘要：
Rill erosion is the process of soil particles separating in the groove and handling by rill flow, and it is one type of surface corrosion, and the rill formed can be completely filled by normal farming activities. In the loess plateau region, rill erosion of slope accounts for more than 70% of the total erosion, and rill erosion is a major erosion in the loess plateau hilly land, and is also an important part of mechanism of slope erosion prediction. Rills are small channels which function as both sediment sources and sediment transport vehicles on hill slopes. It is a quantum leap during the process of soil erosion on slopes, and is also the beginning of qualitative changes in the process of soil erosion. The rill morphology development plays an important role in the understanding of rill erosion. Rill morphology changes have many influence factors in the process of rill erosion, so systematically studying the relationship between rill shape coefficient and influencing factors can make us better understand the process of rill erosion and erosion mechanism. For the study of rill morphological development process, the combination scouring tests of 6 slopes (2°, 4°, 6°, 8°, 10°, and 12°) and 5 discharges (8, 16, 24, 32, and 40 L/min) were carried out, and the effect mechanism of rill transverse profile morphological development on the loess slope surface was investigated, as well as the dynamic characteristics of the impact. The results showed that rill width-depth ratio ranged from 3.006 to 4.841, and according to the hydraulic optimum section, the rill flow was far from steady state. In rill erosion, downward erosion and lateral erosion gradually transited to downward erosion. Because of incised and lateral erosion, rill cross-sectional shape was gradually widened and deepened with the increase of slope and time. Along with the change of slope, cross-sectional shape coefficient varied within the range of 0.36-0.522. Research showed that: The rill cross-sectional shape was approximating to the trapezoidal hydraulic best section with the increase of the flow, slope and scour lasted time, namely the section with the least resistance. With the increase of water flow length, cross section shape changed gradually from wide and deep to narrow, and the cross-sectional shape coefficient was reduced. Through calculation, the groove profile form ranged within 0.6-11.26, and increased with the increase of slope, but had no significant correlation with discharge. With the increase of slope, the average spacing of drop pit on bed face decreased, the depth of drop pit increased, and the groove profile shape coefficient increased. Comprehensive resistance coefficient and energy dissipation showed a good power function relationship with groove profile shape coefficient, and with the increase of profile shape coefficient, the slope shape resistance increased. Rill hydraulic characteristics and groove shape showed the role of mutual connection and restriction and reaction system. Groove profile shape coefficient was larger, the bed surface shape resistance increased, and drop pit also would be developed more maturely. The water in drop pit had strong turbulence and aeration, which had significant effect on energy dissipation. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
引用
下载
收藏
页码：209 / 216
页数：7
相关论文
共 28 条
  • [1] Zhang L., Li Z., Wang S., Impect of runoff regimes on sediment yield and sediment flow behavior at slope scale, Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 31, 20, pp. 124-131, (2015)
  • [2] Dong Y.Q., Zhuang X.H., Lei T.W., Et al., A method for measuring erosive flow velocity with simulated rill, Geoderma, 232, 11, pp. 556-562, (2014)
  • [3] Wu P., Zhou P., Wu C., Et al., Research on the spatial distribution characters of slope rill erosion, Research of Soil and Water Conservation, 4, 2, pp. 47-56, (1997)
  • [4] Bruno C., Stefano C.D., Ferro V., Field investigation on rilling in the experimental Sparacia area, South Italy, Earth Surface Processes and Landforms, 33, 2, pp. 263-279, (2008)
  • [5] He J., Gong H., Li X., Et al., Effects of rill development on runoff and yielding processes, Advances in Water Science, 25, 1, pp. 90-97, (2014)
  • [6] Shen H., Zheng F., Wen L., Et al., The intensity of rainfall and slope comprehensive effects of rill morphological characteristics, Transactions of the Chinese Society for Agricultural Machinery, 46, 7, pp. 162-170, (2015)
  • [7] Cai Q., A study on critical condition about rill taken place on slope, Journal of Sediment Research, 1, pp. 52-59, (1998)
  • [8] Yan D., Wen A., Shi Z., Et al., Purple soil water flow down pit morphological characteristics and its causes, Journal of Mountain Research, 30, 1, pp. 30-35, (2001)
  • [9] Alin L., Keli T., Retrospect and prospect of soil erosion research slope gully system, Journal of soil and water conservation bulletin, 17, 3, pp. 37-43, (1997)
  • [10] Li Z., Heavy rain Erosion Slope Gully Loess Region System Test and Small Watershed Sediment Yield Model Research, (1991)
123