[1]TIAN Pei,QIU Haoran,FENG Yu,et al.Effects of Rainfall Intensity and Slope Gradient on Runoff and Sediment Production and Erosion Dynamic Process on Red Soil Slope[J].Research of Soil and Water Conservation,2020,27(06):1-8.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
27
Number of periods:
2020 06
Page number:
1-8
Column:
目次
Public date:
2020-10-20
- Title:
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Effects of Rainfall Intensity and Slope Gradient on Runoff and Sediment Production and Erosion Dynamic Process on Red Soil Slope
- Author(s):
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TIAN Pei1,2, QIU Haoran1,2, FENG Yu1,2, WU Haoyan1,2, WU Tieniu1,2, LIU Muxing1,2
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(1.Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Wuhan 430079, China; 2.College of Urban and Environmental Sciences, Central China Normal University, Wuhan 430079, China)
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- Keywords:
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red soil sloping land; rainfall intensity; slope gradient; runoff and sediment yield; hydrodynamic parameters; temporal and spatial variation
- CLC:
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S157.1
- DOI:
-
-
- Abstract:
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The overland flow velocity, temporal and spatial variations of runoff and sediment yield, and hydrodynamic processes on the red soil slope in Caidian, Wuhan, Hubei Province were studied under different simulated rainfall intensities(40 mm/h, 66 mm/h, 80 mm/h)and slope gradients(5°, 10° and 15°). The soil sample was filled in a steel trough(2.5 m in length, 0.5 m in width, and 0.3 m in height)with adjustable slope gradient. Each rainfall simulation lasted for 60 minutes after the generation of runoff at the outlet of the trough, and runoff and sediment samples were collected every 3 minutes. The results showed that under the same slope gradient, the average runoff and sediment yield increased with the increase of rainfall intensity; the runoff increased with fluctuation in the early stage of the rainfall, and gradually became stable, while the sediment yield rate increased sharply at the beginning of the rainfall, then decreased slightly, and gradually stabilized; with the slope gradient increasing from 5° to 15°, the average runoff rates at rainfall intensities of 40 mm/h, 66 mm/h and 80 mm/h increased by 24%, 22% and 15%, and the mean sediment yields increased by 89%, 60% and 84%, respectively; with the increase of rainfall intensity or slope, runoff velocity increased, and the effect of rainfall intensity on velocity was greater than that of slope gradient; mean flow velocity increased along the downslope direction, and the velocity in rills was 1.33~2.10 times of that in the interrill; under the condition of 66 mm/h and 10°, rills formed on the slope surface and obvious downcutting erosion and headward erosion occurred; under the same rainfall intensity, the runoff shear force increased and the Darcy-Weisbach resistance coefficient decreased with increase of slope gradient. Under the experimental conditions, the overland flow belonged to laminar flow and supercritical flow. The fitting equation of hydrodynamic parameters and sediment yield rate indicates that Froude number and flow velocity can well simulate the sediment production rate. The results of this study can provide the reference for the control of soil erosion in the red soil area of southern China.