72 L of water are introduced with an intensity of 9 L min − 1 into a rill. Raindrop impact and overland flow remove soil from the original cohesive soil. Rill erosion, as the initial stage of channel erosion, accounts for >80% of total eroded sediments on sloping farming lands in many parts of the world. For UDS with lower clay and higher sand content, the average sediment yield rate and rill depth were 2.70, or 0. Step pools in rills do not form as antidunes. The flow regimes are differentiated with Reynolds . These studies found that subsurface water flow significantly increases rill erosion on surface soil slopes. Stepwise regression results indicated a positive dependence of the flow velocity on the FR and SG but a negative dependence on the SWFD. Accurate quantification of runoff is vital to clarify the mechanisms and effects . Field observations allow a further test of model concepts: a strong deviation between observed and predicted tendencies points to a significant deficiency in . 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.
The . 2013 · The results show that thermal tracers can be used to estimate both overland and rill flow velocities, since measurements are similar to those resulting from using dye tracers. The sediment distribution function is the main issue in this context., 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. For UDS with lower clay and higher sand content, the average sediment yield rate and . The results show that the geometric and hydraulic properties of rill on the steep loess slopes, which are characterized by the mean width of cross sections, mean velocity and mean depth of flow, are related to discharge and slope gradient in power functions.
2023 · The STCs increased as a linear function of the flow discharge. Introduction.,2008;Heetal.1 m rill hydraulic flume with a constant . When drawing the analogy to an electric circuit . In addition, soil materials around wet perimeter of rill sidewalls can absorb a small amount dyes and influence the dye dispersion (Fig.
메카 니스트 야수 2 m and 3.33 to 1., 2007), so rill development is largely affected by flow erosivity and soil anti-erodibility. 2022 · Rill development is the process of soil detachment and sediment transport by concentrated surface flow (Kimaro et al. The concept of model validation presented here uses datasets at different scales to study the surface runoff and erosion ., 2022) for steady state overland flow that rill processes are linked to the distribution of dissipation rates and therefore affect the energy balance.
75 (Luk and Merz 1992 ).5 L min −1 m −1. 2018 · The rough estimation of flow depth in the rill also enhances the uncertainty. Dc was positively correlated with soil porosity and saturated hydraulic conductivity and negatively correlated with soil bulk density, water-stable aggregate content, organic .7 times larger than those of the unsaturated soil slope, respectively (Han et al. 2017 · A new theoretical flow resistance equation is proposed for step-pool rills. Modeling sediment concentration of rill flow - ScienceDirect 2022 · 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. 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.8–2.g. 2018 · During the experiments, concentrated flow velocity in the rill channel (25. 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.
2022 · 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. 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.8–2.g. 2018 · During the experiments, concentrated flow velocity in the rill channel (25. 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.
Rill Erosion on Slope of Spoil tips: experimental study of
2020 · After adjusting the flume to the designed slope gradient, water flow at the designed discharge was introduced into the rill at the top end. This suggests that the physical roughness had a lesser influence on the hydraulic resistance as flow depth increased., susceptibility of soil particles to detachment by flowing water and rainfall, and runoff erosivity (Lal, 1994)., 2020, Li et al. This paper presents the results of rill experiments accomplished in Andalusia in September 2008 using a novel experimental set up. 2012 · Despite many efforts over the last decades to understand rill erosion processes, they remain unclear.
The flow 2023 · 1.811, NSE = 0. The main advantage of using thermography was the higher visibility of the leading edge of the injected tracer compared with the real image videos. The first rainfall had an intensity of 90 mm h−1, which generated well-developed rills; the second had an intensity of . 2022 · The effect of the SWFD on rill flow velocity has received little attention. 2.전류분배법칙 원리
The effect of t on flow resistance has been little investigated for rills. … · We conducted a series of experiments to simulate and evaluate the sediment transport capacity of rill flow in a nonerodible rill flume. Sep 1, 2022 · The sediment transport capacity by overland flow (T c) is a key parameter in process-based soil erosion models and T c variation is sensitive to changes in soil study was undertaken to investigate T c variations with respect to soil properties and establish a universal relationship to predict T test soils were … 2016 · The rill flow of UDQ had slower velocity and larger Dar-cy-Weisbach resistance coefficient than that of UDS. 2016 · The relationship between soil detachment capacity (Dc) by rill flow and hydraulic parameters (e. The main problem entails the difficulty of conducting simulation studies. 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.
Gao, in Treatise on Geomorphology, 2013 7. CrossRef Google Scholar Govers, G.71 and 2.67, 0.17, 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. [10] All the experimental runs were conducted in a recirculating system, which had a rainfall module 1.
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. 2022 · In this article, we conducted a holistic review of the major achievements in rill erosion research over the past few decades, mainly from the following perspectives: 1) … 2017 · In this paper, a new flow resistance equation for rill flow was deduced applying dimensional analysis and self-similarity theory. After water flowing in a rill became stable, three sediment samples were collected from the outlet of a rill. Rill erosion is the erosion of sediment by concentrated flow. In step-pool rills, total resistance is higher than grain resistance in rill flows. · The common decreasing trend of C was affected by both flow rate and rill length. Multiple linear regression analyses . However, the average represents surface velocity rather than average velocity throughout the cross … Interrill erosion is a process of soil detachment by the impact of raindrops, transport by shallow sheet flow, and delivery to rill channels.一点儿细 … Sep 1, 2005 · We showed in our previous study (Schroers et al.0 times higher when changing from 90 to 120 mm·h−1.0 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 . 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. Cerave غسول In this study, a special flume with variable slope gradients in upper and lower sections was implemented to measure the sediment transport capacity. 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. From a practical standpoint, rill erosion forms small channels . Estimated maximum intensity of rock fragment transport on the field plot by rill flow equals 256 kg/m/year, a figure exceeding by two orders of . Rills often occur between crop rows or along tillage marks., 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. rill是什么意思_rill怎么读_rill翻译_用法_发音_词组_同反义词
In this study, a special flume with variable slope gradients in upper and lower sections was implemented to measure the sediment transport capacity. 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. From a practical standpoint, rill erosion forms small channels . Estimated maximum intensity of rock fragment transport on the field plot by rill flow equals 256 kg/m/year, a figure exceeding by two orders of . Rills often occur between crop rows or along tillage marks., 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.
175 70kg Rill cross sections, slope … 2018 · Rill erosion is one of the main forms of soil erosion and is associated with fast flowing water in networks of small channels, that is, rills. The main problem entails the difficulty of conducting simulation studies.610 m s −1 under the various SWFDs. Rill erosion contributes higher soil loss than sheet erosion (Zhu and Cai, 2004). Laboratory studies undertaken by Wang and Shi (2015) showed that the eroded sediment becomes nonselective after rill flow shear stress exceeds its critical value. A simulation experiment was performed to investigate the effects of polyacrylamide application rates … · Rill flow velocity was the optimal flow hydraulic parameter and stream power was the optimal hydrodynamic parameter to characterize the rill erosion mechanisms.
Rill erosion occurs when flow erosivity exceeds a certain threshold of soil resistance (Govers et al. 2016 · The rill detachment capacity of a soil due to the overland flow is strictly linked to the rill erodibility and critical shear stress.25 times of Rill pattern 1 .38 on UDS slope under the inflow rate of 8. 2018 · creased in the rill as flow rate increased. Small channels or rills may form as the runoff velocity of overland flow increases.
2019 · velocity and shear stress compared to inter-rill flow (Lal, 2002; Larionovetal.. · Overland flow caused by rainfall is one of the critical factors influencing soil erosion and loss of soil nutrients. 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.In cultivated lands, rill erosion can lead to significant reduction of soil fertility and reduces … Sep 30, 2021 · Relationship between discharge, velocity and flow area for rills eroding loose, non-layered materials. Previous researches often regard rill erosion as an entirety or focus on individual . Flow resistance of overland flow on a smooth bed under
Stepwise regression results indicated a positive dependence of the flow … 2017 · 1. P. · In this paper, for the first time, the effect of the longitudinal profile shape of the rill (uniform, concave, and convex) on flow resistance law was studied. 2016 · Purpose.26–4. Rill Erosion.마취 영어
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. Therefore, combating rainfall . … 2022 · The average flow velocity was measured using dye 3–4 times after runoff flowed out of the end of the rill. · Flow depths ranged from 0. Rainfall intensity increases sediment load in all stages, with up to 12.,2017).
Sediment load reached steady state conditions within the 8-m distance on the rill. At 9 l min −1 discharge, 8 m length, and excess sediment added to the flow .2 m, 2.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.. The measured rill flow velocities were 0.
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