Effect of soil stratification on the development and migration of headcuts in upland concentrated flows

Gordon, Lee M.; Bennett, Sean J.; Wells, Robert R.; Alonso, Carlos

doi:10.1029/2006wr005659

Cited by 30 publications

(33 citation statements)

References 30 publications

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“…Accordingly, gully soil erodibility, and in particular its critical shear stress and erodibility coefficient, would be affected by such weathering processes (Knapen et al 2007). Previous studies (Alonso et al 2002;Gordon et al 2007;Hanson et al 2001) have also shown that headcuts migrate upstream due to hydraulic stress at the overfall, weathering processes, and seepage at the base of headcuts as well as gravitational forces on soil mass. Therefore, these weathering processes would result in obvious changes to gully erosion processes.…”

Section: Discussionmentioning

confidence: 92%

Influence of bare soil and cultivated land use types upstream of a bank gully on soil erosion rates and energy consumption for different gully erosion zones in the dry-hot valley region, Southwest China

Xiong

Dong

et al. 2015

Nat Hazards

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This study assessed temporal variation in soil erosion rates in response to energy consumption of flow (DE). It employed an in situ bank gully field flume experiment with upstream catchment areas with bare (BLG) or cultivated land (CLG) that drained down to bare gully headcuts. Water discharge treatments ranged from 30 to 120 L Min -1 . Concentrated flow discharge clearly affected bank gully soil erosion rates. Excluding minimal discharge in the CLG upstream catchment area (30 L min -1 ), a declining power function trend (p B 0.1) was observed with time in soil erosion rates for both BLG and CLG upstream catchment areas and downstream gully beds. Non-steady state soil erosion rates were observed after an abrupt collapse along the headcut slope after prolonged scouring treatments. However, as the experiment progressed, DE and energy consumption of flow per unit soil loss (DEu) exhibited a logarithmic growth trend (p \ 0.1) at each BLG and CLG position. Although similar temporal trends in soil erosion and infiltration rates were observed, values clearly differed between BLG and CLG upstream catchment areas. Furthermore, Darcy-Weisbach friction factor (f) values in the CLG upstream catchment area were higher than the corresponding BLG area. In contrast to the BLG upstream catchment area, lower DEu and higher soil erosion rates were observed in the CLG upstream catchment area as a result of soil disturbances. This indicated that intensive land use changes accelerate soil erosion rates in upstream catchment areas of bank gullies and & Donghong Xiong increase soil sediment transport to downstream gullies. Accordingly, reducing tillage disturbances and increasing vegetation cover in upstream catchment areas of bank gullies are essential in the dry-hot valley region of Southwest China.

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Section: Discussionmentioning

confidence: 92%

Influence of bare soil and cultivated land use types upstream of a bank gully on soil erosion rates and energy consumption for different gully erosion zones in the dry-hot valley region, Southwest China

Xiong

Dong

et al. 2015

Nat Hazards

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“…This trend was caused by the high flow discharge generating more overland flow, which then influenced the flow hydraulic characteristics by increasing the local turbulence (Guy, Dickinson, & Rudra, 1987). On the one hand, the increasing flow discharge increased the depth of the scour hole on the gully head, thus increasing the collapse frequency of the overhanging layers of the gully heads (Chen et al, 2013;Gordon, Bennett, Wells, & Alonso, 2007) and increasing the undercut sediment. The runoff that dropped from the border of the catchment area was divided into the wall pressing flow and the jet flow (Flores-Cervantes, Istanbulluoglu, & Bras, 2006).…”

Section: Sediment Characteristics Of Headcut Erosionmentioning

confidence: 99%

The impact of flow discharge on the hydraulic characteristics of headcut erosion processes in the gully region of the Loess Plateau

Shi

Wang

Chen

et al. 2019

Hydrological Processes

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Headcut erosion is associated with major hydraulic changes induced by the gully head of concentrated flow. However, the variation in the hydraulic characteristics of the headcut erosion process is still not clear in the gully region of the Loess Plateau.A series of rainfall combined scouring experiments (flow discharges ranging from 3.6 to 7.2 m 3 hr −1 , with 0.8 mm min −1 rainfall intensity) were conducted on experimental plots to clarify the variation in the hydraulic parameters induced by gully head and erosion processes under different flow discharges. The results showed that concentrated flows in the catchment area and gully bed were turbulent (Reynolds number ranging from 1,876 to 6,693) and transformed between supercritical and subcritical (Froude number ranging from 0.96 to 3.73). The hydraulic parameters, such as the flow velocity, Reynolds number, shear stress, stream power, Darcy-Weisbach friction factor, and unit stream power in the catchment area were 0.45-0.59 m s −1 , 2086-6693, 1.96-5.33 Pa, 0.89-2.86 W m −2 , 0.08-0.16, and 0.023-0.031 m s −1 ,respectively. When the concentrated flows dropped from the gully head, the hydraulic parameters in the gully bed decreased by 3., respectively, which contributed to the flow energy consumption at the gully head. As flow discharge increased, Reynolds number, shear stress, and stream power increased, while flow velocity, Froude number, unit stream power, and Darcy-Weisbach friction factor did not. The flow energy consumption at the gully head was 9. 66-10.13, 13.25-13.74, 15.68-16.41, and 19.28-20.25 J s −1 , respectively, under different flow discharges and accounted for 60.58-68.50% of the flow energy consumption of the experimental plots. Generally, the sediment discharges increased rapidly at the initial stage, then increased slowly, and finally reached a steady state condition, which showed a significant declining logarithmic trend with experimental duration (P<.01) and increased with increasing flow discharge. Accordingly, the flow energy consumption was significantly correlated with the sediment yield. These findings could improve our understanding of the hydraulic properties and flow energy characteristics of headcut erosion.

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“…The experimental facility utilized packed soil beds, applied rainfall and overland fl ow, and a pre-formed step to trigger headcut development. The following observations were made (refer to Bennett, 1999;Bennett et al, 2000a;Bennett and Casalí, 2001;Gordon et al, 2007b): (1) After an initial period of bed adjustment, steady-state soil erosion conditions were observed where a scour hole (headcut) migrated upstream at a constant rate, its scour depth S D (the vertical distance from the brinkpoint to the maximum scour depth) and scour length S L (the horizontal distance from the brinkpoint to the maximum scour depth) remained nearly invariant with distance, and the sediment discharge Q s exiting the fl ume remained nearly invariant with time. (2) Larger, steady-state headcut scour holes with higher sediment discharges were observed for higher overland fl ow rates, higher bed slopes, and larger initial step heights.…”

Section: Introductionmentioning

confidence: 99%

Effect of soil texture, tailwater height, and pore‐water pressure on the morphodynamics of migrating headcuts in upland concentrated flows

Wells

Bennett

Alonso

2009

Earth Surf Processes Landf

Self Cite

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Rill and gully erosion in upland and agricultural areas can result in signifi cant soil degradation worldwide, and headcuts are the primary mechanism by which this landscape dissection occurs. Experiments were conducted to further examine the morphodynamic behavior of actively migrating headcuts in upland concentrated fl ows with varying boundary conditions. The effect of soil texture greatly modifi ed the erodibility of the select soils, and headcut migration rates, scour depths, and sediment discharges were correlated to the critical shear stress and erodibility of the select soils. The effect of increasing tailwater height greatly reduced the nappe entry angle at the brink of the headcut, completely arresting the soil erosion processes. Altering subsurface pore-water pressures markedly changed the erodibility coeffi cients of the select soil, which caused greater headcut migration rates and sediment discharges, yet shallower scour holes, in the presence of a subsurface water table. Current analytic formulations based on jet impingement theory successfully predicted these experimental observations, further demonstrating the utility of such analytic formulations in advancing watershed management technology.

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Effect of soil stratification on the development and migration of headcuts in upland concentrated flows

Cited by 30 publications

References 30 publications

Influence of bare soil and cultivated land use types upstream of a bank gully on soil erosion rates and energy consumption for different gully erosion zones in the dry-hot valley region, Southwest China

Influence of bare soil and cultivated land use types upstream of a bank gully on soil erosion rates and energy consumption for different gully erosion zones in the dry-hot valley region, Southwest China

The impact of flow discharge on the hydraulic characteristics of headcut erosion processes in the gully region of the Loess Plateau

Effect of soil texture, tailwater height, and pore‐water pressure on the morphodynamics of migrating headcuts in upland concentrated flows

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