[1]Rui Maogang,Zhou Yanchen.Study on the Dynamic Hydrodynamic Characteristics of Runoff on the Slope of Red Soil Engineering Accumulation[J].Research of Soil and Water Conservation,2024,31(03):143-152,159.[doi:10.13869/j.cnki.rswc.2024.03.043]
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
31
Number of periods:
2024 03
Page number:
143-152,159
Column:
Public date:
2024-04-30
- Title:
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Study on the Dynamic Hydrodynamic Characteristics of Runoff on the Slope of Red Soil Engineering Accumulation
- Author(s):
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Rui Maogang1, Zhou Yanchen1,2
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(1.Yunnan Institute of Water Resources and Hydropower Research, Kunming 650228, China; 2.Changjiang River Scientific Research Institute of Changjiang Water Resources Commission, Wuhan 430010, China)
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- Keywords:
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soil and water conservation; red soil accumulation; rainfall test; dynamic hydrodynamic; erosion
- CLC:
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S157.1
- DOI:
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10.13869/j.cnki.rswc.2024.03.043
- Abstract:
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[Objective] The aim of this study are to explore the characteristics of hydrodynamic parameters on the slope runoff of two typical artificial disturbance engineering accumulations, bare slope and soil rock mixture under rainfall conditions, to quantify the critical conditions for erosion dynamics of accumulations, and to lie the foundation for elucidating the erosion dynamics mechanism of accumulations. [Methods] This study focused on the loose red soil engineering accumulation as the research object. The runoff dynamic hydrodynamic characteristics of bare slope and mixed soil and rock accumulation(20% gravel content)under different rainfall intensity conditions through simulated rainfall experiments were analyzed. The critical dynamic conditions for erosion of different accumulations were quantified. The research on the internal mechanisms of accumulation erosion was conducted. [Results] The runoff of accumulations changed from laminar slow flow to laminar jet flow, and Darcy-Weisbach increased by 1.40~3.54 times, with the increase of rainfall intensity from 1.0 mm/min to 2.0 mm/min. The runoff shear stress and runoff power of the accumulation showed an overall increasing trend with the increase of rainfall intensity. When the rainfall intensity was 1.0 mm/min, the average runoff shear stress of the soil rock mixed accumulation decreased by 44.99% compared to the bare slope. However, when the rainfall intensity was more than 1.5 mm/min, it increased by 2.90%~18.50%. The gravel action reduced the average runoff power by 10.38%~68.13% compared to bare slopes under three rainfall intensities. The gravel action also reduced the unit runoff power and the unit energy of the water flow section by 20.11%~40.45% and 21.06%~37.57%, respectively. The runoff power parameter was used to characterize the dynamic changes of slope erosion in accumulations. When the rainfall intensity was less than 1.5 mm/min, gravel could inhibit accumulation erosion, and the critical runoff power increased by 19.38%~138.12%, resulting in a decrease of 79.87%~83.51% in soil erodibility. When the rainfall intensity reached up to 2.0 mm/min, the critical runoff power decreased by 97.87%, and the soil erodibility increased by 347.43%. [Conclusion] Rainfall intensity has a significant impact on the hydrodynamic parameters of both bare slopes and mixed soil and rock accumulations. However, as rainfall intensity increases, the role of gravel in regulating erosion of the accumulations will change, a critical rainfall intensity can be indentified.