84 times that of UDQ. The decrease in hydraulic roughness as a function of Nr is well documented [Chow, 1959, pp. Decreasing the SWFD from 15 to 5 cm increased … · 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 . Sep 17, 2021 · Since rill erosion depends on rill flow characteristics , a key to model rill erosion processes is to determine hydraulic variables as flow discharge Q, water depth … 2017 · Seven flow discharges were combined with six slopes. The dye tracer method is the most widely used method for measuring rill flow velocity, but the … 2016 · A comprehensive process-based rainfall-runoff model for simulating overland flow generated in rills and on interrill areas of a hillslope is evaluated using a laboratory experimental data set. The two parallel experiments under two snowmelt waterflow rates showed consistent results with respect to the process of runoff generation and sediment transport and in terms of the influence of thawed soil depth, thus demonstrating … 2018 · For a developing rill, the rill flow velocity is variable responding to the changing rill geometry; whereas the rill flow velocity shows limited variability with time for a … 2016 · After the flow discharge stabilised, flow depth measurements were taken using a level probe with an accuracy of 0. 2023 · The rill component of soil erosion is frequently dominant relative to the interrill one [2, 9]. The formation of head-cuts along the bed of long rills was an important erosion process affecting C and PSD. CrossRef Google Scholar Govers, G. 2021 · 20 stage, the rill development stage and the rill adjustment stage.80.Uniform flow equations, … · In this paper, a recently deduced flow resistance equation for open channel flow was tested under equilibrium bed-load transport conditions in a rill.
The value of α could be estimated with an equation of the rill depth and Reynolds number (R² = 0. This study used three experimental design methods, including the full . Experimental runs were conducted for . Step pools in rills do not form as antidunes. 2022 · The effect of the SWFD on rill flow velocity has received little attention. 2017 · 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.
The results of this study provide a reference for rill flow velocity measurement using the dye tracer method. The SWFD had notable effects on the rill flow velocity. The main problem entails the difficulty of conducting simulation studies. A relationship for rill flow velocities was proposed., 2002, Wu and Zhu, 1994). 4 b).
남자 여름바지 인기 순위 추천 2023년 랭킹차트 프로질러 , 1990). At first, the incomplete self … 2022 · 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. After the water flow in the soil flume approached the steady state, sediment-laden water samples were collected at the outlets of the rills of various lengths (1 m, 2 m, 3 m, 4 m, 5 m, 6 m, 7 m and 8 m) before … 2018 · In this study, we investigated rill flow velocity regimes for both developing and stationary rills using 5 m-length plots in the laboratory. · Rill flow occurs if the critical water level of sheet flow is exceeded.25 times of Rill pattern 1 . First, the flow resistance equation was deduced applying dimensional analysis and the incomplete self-similarity condition for the flow velocity distribution.
1997 · This result was due to interactions of slope gradient, flow rate, erosion, and the formation of rill roughness, bed structures, and head cuts.2. 2022 · In this study, laboratory experiments were used to measure rill flow velocity by using electrolyte tracer method under different hydraulic conditions: flow rates of 1, 2, 4, and 8 L/min, slope .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 ., 2018). Sep 9, 2010 · The experiments were performed to study how rill networks initiate and evolve over time under controlled conditions with regard to the treatment variables considered, and to allow for input in a computer simulation model. Modeling sediment concentration of rill flow - ScienceDirect 8m A series of inflow experiments was conducted on loess slopes.3 General Approaches on Rill Erosion.5, and 0. The flow regimes are differentiated with Reynolds .7 mm and 128 kg/m 2, respectively. 2014 · Channels (rill, ephemeral gully, gully and river channel) exhibit a continuum of sizes and flow magnitudes.
8m A series of inflow experiments was conducted on loess slopes.3 General Approaches on Rill Erosion.5, and 0. The flow regimes are differentiated with Reynolds .7 mm and 128 kg/m 2, respectively. 2014 · Channels (rill, ephemeral gully, gully and river channel) exhibit a continuum of sizes and flow magnitudes.
Rill Erosion on Slope of Spoil tips: experimental study of
一点儿细 … Sep 1, 2005 · We showed in our previous study (Schroers et al. Rills often occur between crop rows or along tillage marks. · Overland flow caused by rainfall is one of the critical factors influencing soil erosion and loss of soil nutrients. 2007 · Rill flow and rill detachment experiments provide an opportunity to investigate to what extent the concepts used in models are a truly valid description of the erosion processes occurring.17, respectively, and all of them were>1, which indicated a supercritical flow; however, they were all significantly lower than the average overland flow Fr of 3. The first rainfall had an intensity of 90 mm h−1, which generated well-developed rills; the second had an intensity of .
[10] All the experimental runs were conducted in a recirculating system, which had a rainfall module 1. In step-pool rills, total resistance is higher than grain resistance in rill flows., 2009 . Once eroded soil enters overland flow, either as aggregates or primary particles, a significant proportion of it returns to the soil bed, forming a cohesionless deposited layer from which it can be removed again by the same erosion processes. Dye tracers have long been used for shallow overland and rill flow velocity measurements., 2008).여스갤 아카이브
53 times of UDQ, respectively, and the rill erodibility parameter was 1., susceptibility of soil particles to detachment by flowing water and rainfall, and runoff erosivity (Lal, 1994). 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. 2023 · The STCs increased as a linear function of the flow discharge. 2020 · Water flow was introduced into the rill at 1, 2, 4 and 8 m from the rill outlet, step by step. The USLE is written as:.
Digital elevation models were calculated by means of photogrammetry for .75, 0. At present, the available literature results confirm that the choice of an appropriate α v value for correcting the … At first, in this paper, a review of the two different approaches to estimate rill flow velocity, based on flow regime and flow resistance laws, is presented. Studies have shown that rill erosion can account for more than 90% of total slope erosion [7,8]. See more. 2022 · The measured rill flow velocities were 0.
4 and 1.8–2. … · We conducted a series of experiments to simulate and evaluate the sediment transport capacity of rill flow in a nonerodible rill flume. | Find, read and cite all the research you . 2023 · Sediment transport capacity in rills is an important parameter for erosion modeling on hillslopes. For laboratory experiments, a rainfall simulator has been constructed together with a 6. Nine depths were measured for each combination of flow discharge and slope gradient, and each combination was .417 × 10 − 3 m 3 /s., precipitation), soil properties, and surface cover flow .50 m × 1. · The common decreasing trend of C was affected by both flow rate and rill length. 22 The average rill depth was the best indicator of rill morphology for evaluating rill erosion. 트위터 인기 순위 This suggests that the physical roughness had a lesser influence on the hydraulic resistance as flow depth increased. 2018 · During the experiments, concentrated flow velocity in the rill channel (25., 2017)., 2007), so rill development is largely affected by flow erosivity and soil anti-erodibility. Accurate quantification of runoff is vital to clarify the mechanisms and effects . For Re greater than 2000 the rainfall intensity effects on flow resistance can be considered negligible ( Yoon and Wenzel, 1971 ), while . rill是什么意思_rill怎么读_rill翻译_用法_发音_词组_同反义词
This suggests that the physical roughness had a lesser influence on the hydraulic resistance as flow depth increased. 2018 · During the experiments, concentrated flow velocity in the rill channel (25., 2017)., 2007), so rill development is largely affected by flow erosivity and soil anti-erodibility. Accurate quantification of runoff is vital to clarify the mechanisms and effects . For Re greater than 2000 the rainfall intensity effects on flow resistance can be considered negligible ( Yoon and Wenzel, 1971 ), while .
포드 테리토리 나무위키 Statistically, power, exponential and logarithmic-linear equations can be used to describe the interrelations of . 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. Recent … 2022 · In the third experiment, the rill flow adjusted some parts of the already developed rill.26–4. Previous researches often regard rill erosion as an entirety or focus on individual . The flow 2023 · 1.
38 on UDS slope under the inflow rate of 8. The measured rill flow velocities were 0. … 2022 · In the case of a strong rill flow component, the potential energy maximum is located close to the transition zone, where turbulence or at least mixed flow may emerge.33 × 10 − 3 and 0. P. Statistically, power, exponential and logarithmic-linear equations can be used to describe the interrelations of .
A theoretical rill flow resistance equation, obtained by the integration of a power velocity distribution, was assessed using available measurements at plot scale with a biochar added soil.7% to 73% and silt of . At each distance, depths were, respectively, measured at points 1. Velocity Relationships.0 cm and slopes ranged from 0. This paper reports the results of a plot investigation aimed to establish the suitable accuracy of the rill thalweg measurement to determine the … 2016 · The rill flow of UDQ had slower velocity and larger Darcy–Weisbach resistance coefficient than that of UDS. Flow resistance of overland flow on a smooth bed under
The sediment concentration was determined with the traditional oven-dry method. This solution considers the . 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. There is an increasing trend for sediment load and sediment concentration with the rising slope gradient . Assessment of the interrill and rill contributions to total soil loss from an upland field plot., sediment … 2023 · rill: 1 n a small stream Synonyms: rivulet , run , runnel , streamlet Type of: stream , watercourse a natural body of running water flowing on or under the earth n a … 2019 · Abstract.롤 계정 이메일 변경
Rill erosion contributes higher soil loss than sheet erosion (Zhu and Cai, 2004). When drawing the analogy to an electric circuit . The results were very good and demonstrated the simplicity and robustness of the method. 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., 2022) for steady state overland flow that rill processes are linked to the distribution of dissipation rates and therefore affect the energy balance. This study provides a strategy to .
Therefore, the applicability of . Table 3 displays the improvements in hydraulic and hydrodynamic variables assessed at 5, .0 times higher when changing from 90 to 120 mm·h−1. In this study, a special flume with variable slope gradients in upper and lower sections was implemented to measure the sediment transport capacity. This paper reports the results of a plot investigation aimed to establish the suitable accuracy of the rill thalweg measurement to determine the … 2021 · Purpose 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 fixed bed rills. 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.
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