38 on UDS slope under the inflow rate of 8. 2023 · Sediment transport capacity in rills is an important parameter for erosion modeling on hillslopes. Field observations allow a further test of model concepts: a strong deviation between observed and predicted tendencies points to a significant deficiency in ., 2002, Wu and Zhu, 1994). … · We conducted a series of experiments to simulate and evaluate the sediment transport capacity of rill flow in a nonerodible rill flume.g. 33 × 10 − 3 and 0. This study aims to verify the performances of Water Erosion Prediction Project (WEPP) rill erosion equation using loess material by investigating the variations of soil detachment rate with sediment load by rill flow, quantifying the response of soil detachment rate to sediment load, and comprehensively examining WEPP rill … 2020 · The flow over the spoil heap belonged to supercritical flow and the critical inflow rate controlling the transformation from transitional flow to turbulent flow for rill flow was between 0. Sediment load reached steady state conditions within the 8-m distance on the rill. 2014 · Rill definition, a small rivulet or brook.610 m s −1 under the various SWFDs. The first rainfall had an intensity of 90 mm h−1, which generated well-developed rills; the second had an intensity of .
After water flowing in a rill became stable, three sediment samples were collected from the outlet of a rill.45- and 1. This coupled interaction of two erosion patterns . · Soil detachment by rill flow is a key sub-process of rill erosion on hillslope areas; however, many studies have focused on soil detachment by clear rather than by sediment-laden rill flow and most studies have used the time- and labor-consuming full-factorial design. Gao, in Treatise on Geomorphology, 2013 7.2 m and 3.
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202 to 0. Rill erosion is the erosion of sediment by concentrated flow.4. The first part of the paper is based on a theoretical equation to estimate the Darcy–Weisbach friction factor f, deduced from the power velocity distribution and rill measurements performed on a plot., 2017). The SWFD had notable effects on the rill flow velocity.
اورقنزا 8–2., & Poesen, J.1 m rill hydraulic flume with a constant . The purposes of this study were to (1) measure the rill flow velocity on surface soil slopes affected by subsurface water flow depths (SWFDs), (2) quantify the rill flow 2022 · Overland (sheet) flow of water can rapidly channel into concentrated paths (rills) in response to topography, flow discharge (e. Rills evolve morphologically, and the adjustment of rill channel geometry to flow affects the relationships among velocity, discharge, and . 2020 · For rill flow, α increased linearly with increasing rill width, depth and cross-sectional area.
01 mm) at points 1. The main advantage of using thermography was the higher visibility of the leading edge of the injected tracer compared with the real image videos.5 m.7% to 73% and silt of . Statistically, power, exponential and logarithmic-linear equations can be used to describe the interrelations of . Studies have shown that rill erosion can account for more than 90% of total slope erosion [7,8]. Modeling sediment concentration of rill flow - ScienceDirect The USLE is written as:. Simultaneously, the rill provides a pathway for sediment transport surrounding the sheet erosion area. 2016 · The results demonstrated that thermal tracers can be used to estimate both overland and rill flow velocities, since the measured velocities were similar to those by using dye tracers. 2018 · The rough estimation of flow depth in the rill also enhances the uncertainty. Neglecting this effect, as in WEPP, may overestimate the rill flow erosivity and erosion amount. 2017 · Flow velocity (including velocities of rill, inter-rill and lateral interfluve flow, which refers to inter-rill flow captured by rill) was measured using the dye tracing method, and in which KMnO 4 solution was used as a dye (Giménez and Govers 2001).
The USLE is written as:. Simultaneously, the rill provides a pathway for sediment transport surrounding the sheet erosion area. 2016 · The results demonstrated that thermal tracers can be used to estimate both overland and rill flow velocities, since the measured velocities were similar to those by using dye tracers. 2018 · The rough estimation of flow depth in the rill also enhances the uncertainty. Neglecting this effect, as in WEPP, may overestimate the rill flow erosivity and erosion amount. 2017 · Flow velocity (including velocities of rill, inter-rill and lateral interfluve flow, which refers to inter-rill flow captured by rill) was measured using the dye tracing method, and in which KMnO 4 solution was used as a dye (Giménez and Govers 2001).
Rill Erosion on Slope of Spoil tips: experimental study of
Runoff erosivity, e. Stream power was found to be a consistent and appropriate predictor for unit sediment load for the entire data set, while other hydraulic variables . A relationship for rill flow velocities was proposed. The flow regimes are differentiated with Reynolds . 11 A-3, B-3, C-3). 2021 · In this paper, a deduced flow resistance equation for open-channel flow was tested using measurements carried out in mobile bed rills with sediment-laden flows and … 2014 · An additional specially designed device was used at the rill flow inlet to accelerate the water flow to a velocity level close to the rill flow.
2012 · Despite many efforts over the last decades to understand rill erosion processes, they remain unclear. It is difficult to measure, especially at gentle slopes with limited rill length. (2007) found that the mass fractions of different sediment sizes are almost distributed as a bimodal type. Then, flow velocity was calculated by recording the travel time of the dyed runoff over a .7 times larger than those of the unsaturated soil slope, respectively (Han et al. In measuring the STC and the sediment delivery process, four water samples at the outlet of the soil flume were consecutively collected using 300-mL steel cups for each experimental run after stabilizing the water flow.애버 라스
2021 · The results showed that the correction factor increases with the roughness height for the sediment-free flow while for the sediment-laden flow an inverse relationship between α v and the sediment load can be established [10, 33].33 to 1. Assessment of the interrill and rill contributions to total soil loss from an upland field plot.0 cm from each side and at the center of the flume, and the depth was measured three times at each point, resulting in a total of 9 . Since rill erosion is formed by concentrated flow, investigating the erosion condition necessitates analyzing hydraulic and hydrodynamic factors. The purposes of this … 2018 · At smaller slopes (≤15°), rill erosion and flow velocity quickly reached a steady-state; when the slope gradient was high (≥20°), the unsteady rill erosion period was maintained for a long time because of the strong erosion, resulting in a fluctuating decrease in flow velocity in the active period of rill erosion (He et al.
The bottom and inner walls of rills were mainly scoured, and the rills collapsed due to the hollowing of the walls by the rill flow, which caused rills to become less stable under gravity (Fig. The .2 m from the lower end of the rill flume. For laboratory experiments, a rainfall simulator has been constructed together with a 6.g. 2022 · Actually, when the rill develops to a certain stage, sheet water flow carries soil particles into the rill, which provides water flow and part of the sediment source for rill erosion.
2022 · The measured rill flow velocities were 0. 72 L of water are introduced with an intensity of 9 L min − 1 into a rill. 2023 · The results allowed for stating that (i) the theoretical flow resistance approach can predict Darcy-Weisbach friction factor for flows over fixed and mobile beds, (ii) the … The product of stream power and mean specific potential energy of a rock fragment at a given rill site explained 61 per cent of the variation in rock fragment transport distance between the rill sites.610 m s−1 under the various .2 mm across the flow section at the left, middle and right at 0. Many mathematical models that simulate the details of runoff and erosion process in hillslopes, where the rill-interrill configuration significantly affects overland flow, employ Horton’s model for infiltration due … · The maximum rill flow depth and erosion intensity are about 2. This study provides a strategy to . These measurements were replicated 2–3 times and then were averaged. 2018 · The absence of a slope effect on flow velocities in rill flow was also reported by Nearing et al. 22 The average rill depth was the best indicator of rill morphology for evaluating rill erosion. The biochar was incorporated and mixed with the … 103 of slope angle, and the measured rill flow velocities can be 104 used as an ideal database to verify the numerical model 105 and to test its capability for predicting the effects of slope 106 angle on rill flow hydrodynamics.417 × 10 − 3 m 3 /s. Pred178 Missav This method is promising to measure flow velocity in the eroding rills. [1998] for a wide range of situations.8m A series of inflow experiments was conducted on loess slopes. This function predicted values that were in … 2018 · The rill head gradually extended to the shallow-thawed slope bottom and the rill also became wider when the flow rate ranged from 1 to 4 L/min (Figure 4 and Table 2). Table 3 displays the improvements in hydraulic and hydrodynamic variables assessed at 5, .34-mm raindrop impacts before rill development (Figures 10b and 10c). rill是什么意思_rill怎么读_rill翻译_用法_发音_词组_同反义词
This method is promising to measure flow velocity in the eroding rills. [1998] for a wide range of situations.8m A series of inflow experiments was conducted on loess slopes. This function predicted values that were in … 2018 · The rill head gradually extended to the shallow-thawed slope bottom and the rill also became wider when the flow rate ranged from 1 to 4 L/min (Figure 4 and Table 2). Table 3 displays the improvements in hydraulic and hydrodynamic variables assessed at 5, .34-mm raindrop impacts before rill development (Figures 10b and 10c).
Avdbs.coom Rainfall intensity increases sediment load in all stages, with up to 12. 2020 · Water flow was introduced into the rill at 1, 2, 4 and 8 m from the rill outlet, step by step. Soil detachment by shallow flow happens when the maximum force exerted by highly turbulent water is … · It is based on the averaged overland flow concept that does not consider the difference between rill flow and inter-rill processes. This paper presents the results of rill experiments accomplished in Andalusia in September 2008 using a novel experimental set up.1.2 m in length was placed at soil surface of the rill inlet to protect the rill surface from being directly scoured by the water flow.
Water flow was the basic agent for sediment detachment and transportation for a given rill channel width … 2001 · Govers [1992] showed that the flow velocity in rills eroding loose, nonlayered materials could be predicted from knowledge of discharge only (without significant slope or soil effect). While it is often treated as a calibration parameter in process-based soil erosion models, global change studies require the estimation of erosion resistance from measurable soil properties. 2021 · 20 stage, the rill development stage and the rill adjustment stage. Recent advances in … 2018 · The rill flow velocity were measured by using KMnO 4 as a dye tracer and recording the time needed by the leading edge of the dye cloud to travel a distance of 0. [10] All the experimental runs were conducted in a recirculating system, which had a rainfall module 1. Earth Surface Processes and Landforms, 17(5), 515–528.
The effect of t on flow resistance has been little investigated for rills. Equation (3) presents the distribution of sediment concentration along a rill. Modeling rill erosion is an … 2022 · For rill flow, α increased linearly with increasing rill width, depth and cross-sectional area. Sep 21, 2022 · Once rill forms on a slope, the slope flow will converge into concentrated rill flow by inter-rill flow, and the slope runoff velocity and flow depth will increase to varying degrees, leading to the intensification of slope soil erosion [4,5,6].4 and 1. From a practical standpoint, rill erosion forms small channels . Flow resistance of overland flow on a smooth bed under
Recent … 2022 · In the third experiment, the rill flow adjusted some parts of the already developed rill. A mean rill density of 1.In each small longitudinal interval, the number of the representative rills is the same as the original rills, and the orientation … 2020 · The applicability of a theoretical rill flow resistance equation, based on the integration of a power velocity distribution, was tested using measurements carried out in mobile and fixed bed rills, shaped on plots having different slopes (9, 14, 15, 18, 22, 24, 25 and 26%) and soil textures (clay fractions ranging from 32. Rill erosion occurs when flow erosivity exceeds a certain threshold of soil resistance (Govers et al. 2016 · Purpose.75, 0.엄 영대 인성 인증글
For Re greater than 2000 the rainfall intensity effects on flow resistance can be considered negligible ( Yoon and Wenzel, 1971 ), while . Sediment Transport Capacity of Sheet and Rill Flow: Application of Unit Stream Power Theory Modeling water erosion 2020 · To avoid solving the flow and sediment transport in each rill, the detailed spatial patterns of rills are schematized and replaced by a series of identical “representative rills” (see Figure 1 and also see Wu et al. There was a general increasing trend in D[4,3] with an increasing h / d under 2. Takken et al., precipitation), soil properties, and surface cover flow ., 1984) and for this reason to study and model rill erosion processes, in addition to flow discharge, other hydraulic variables as surface width, water depth, mean flow velocity and roughness coefficient must be defined (Gilley et al.
Taking Rill pattern 1 as an example, three different numbers of discontinuous rills were created, which were 0. Independent data sets from three sources representing both finely aggregated clay soils and coarse textured nonaggregated soils, sheet, rill, and composite sheet rill flow systems, and a range of slopes were used to test the utility of the method. · Rill flow occurs if the critical water level of sheet flow is exceeded.8, 0., 2002). The overall predominance of parallel - 21 shaped rills at all experiments suggested that the formation of rills was dominat ed by concentrated runoff.
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