Correction factor for rill flow velocity measured by the dye tracer method under varying rill morphologies and hydraulic characteristics

2020 ◽  
Vol 591 ◽  
pp. 125560
Author(s):  
D.M. Yang ◽  
N.F. Fang ◽  
Z.H. Shi
Keyword(s):  
Flow Velocity ◽  
Correction Factor ◽  
Hydraulic Characteristics ◽  
Tracer Method ◽  
Dye Tracer ◽  
Rill Flow

Comparison of rill flow velocity over frozen and thawed slopes with electrolyte tracer method

2016 ◽  
Vol 534 ◽  
pp. 630-637 ◽  
Author(s):  
Yunyun Ban ◽  
Tingwu Lei ◽  
Zhiqiang Liu ◽  
Chao Chen
Keyword(s):  
Flow Velocity ◽  
Tracer Method ◽  
Rill Flow

Assessing dye-tracer technique for rill flow velocity measurements

CATENA ◽  
2018 ◽  
Vol 171 ◽  
pp. 523-532 ◽  
Author(s):  
Costanza Di Stefano ◽  
Vito Ferro ◽  
Vincenzo Palmeri ◽  
Vincenzo Pampalone
Keyword(s):  
Flow Velocity ◽  
Tracer Technique ◽  
Velocity Measurements ◽  
Dye Tracer ◽  
Rill Flow

scholarly journals Application of digital image processing in slope surface runoff velocity analysis under simulated rainfall conditions

2017 ◽  
Vol 49 (4) ◽  
pp. 1304-1312
Author(s):  
Tiexiong Gong ◽  
Yuanjun Zhu
Keyword(s):  
Image Processing ◽  
Surface Runoff ◽  
Lateral Diffusion ◽  
Ease Of Use ◽  
Velocity Analysis ◽  
Slope Gradient ◽  
Tracer Method ◽  
Dye Tracer ◽  
The Mean ◽  
High Runoff

Abstract To have accurate runoff velocity, there is need to improve dye tracer method for estimating surface runoff velocity. This can enhance the calculations of relevant hydrologic parameters that will lead to a better understanding of hydrological processes and soil erosion. In this study, an integrated dye tracer and image processing method (IPV) and dye tracer method (AOV), respectively, were used to estimate runoff velocity under three slope gradients (5°, 10°, and 15°) and three slope positions (up-slope, mid-slope, and down-slope). The results showed more variation in runoff velocity under IPV than AOV. Both IPV and AOV were positively correlated with slope gradient. IPV values were close to AOV ones for slope gradients ≤5°, but were significantly different for slope gradients ≥10°. The mean AOV value was 10.6% higher than that of IPV. Regression analysis showed that compared with AOV, IPV overestimated and underestimated runoff under low and high runoff velocity conditions, respectively. The use of image processing in IPV was advantageous because of its ease of use with fewer artificial errors and its suitability for lateral diffusion of runoff. Irrespectively, additional studies are needed to verify and/or improve further the use of this method in runoff velocity analysis.

scholarly journals Debris-flow velocities and superelevation in a curved laboratory channel

2015 ◽  
Vol 52 (3) ◽  
pp. 305-317 ◽  
Author(s):  
Christian Scheidl ◽  
Brian W. McArdell ◽  
Dieter Rickenmann
Keyword(s):  
Debris Flow ◽  
Flow Velocity ◽  
Correction Factor ◽  
Debris Flows ◽  
Laboratory Experiments ◽  
Flow Conditions ◽  
Vortex Equation ◽  
Flow Surface ◽  
Sediment Mixture ◽  
Sediment Mixtures

The vortex equation is often used to estimate the front velocity of debris flows using the lateral slope of the flow surface through a channel bend of a given radius. Here we report on laboratory experiments evaluating the application of the vortex equation to channelized debris flows. Systematic laboratory experiments were conducted in a 8 m long laboratory flume with a roughened bed, semi-circular cross section (top width 17 cm), and two different bend radii (1.0 and 1.5 m) with a common bend angle of 60°, and two channel inclinations (15° and 20°). Four sediment mixtures were used with systematic variations in the amount of fine sediment. In the experiments, 12 kg of water-saturated debris were released in a dam-break fashion, and multiple experiments were conducted to verify the repeatability for a given sediment mixture. Data are available for 69 experimental releases at a channel inclination of 20° and 16 releases at an inclination of 15°. Flow velocity was determined with high-speed video, and flow depth and the lateral inclination of the flow surface (superelevation) were measured using laser sensors. In general, the results from an individual sediment mixture are repeatable. We found that the channel slope as well as centerline radius have a significant influence on the correction factor k used in the vortex equation. Relatively coarse-grained sediment mixtures have larger superelevation angles than finer-grained mixtures. We found a statistically significant relation between the correction factor and Froude number. Correction factors of 1 < k < 5 were found for supercritical flow conditions. However, for subcritical flow conditions the correction factor shows a larger value as a function of the Froude number, which leads to an adaption of the forced vortex formula considering active and passive earth pressures. Finally, based on our experimental results, we present a forced vortex equation for debris-flow velocity estimation without a correction factor.

Measuring flow velocity under straw mulch using the improved electrolyte tracer method

2013 ◽  
Vol 495 ◽  
pp. 121-125 ◽  
Author(s):  
Abbas E. Rahma ◽  
Tingwu Lei ◽  
Xiaonan Shi ◽  
Yuequn Dong ◽  
Shumei Zhou ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Tracer Method ◽  
Straw Mulch

Nitrogen removal during summer and winter in a primary facultative waste stabilization pond: preliminary findings from 15N-labelled ammonium tracking techniques

2010 ◽  
Vol 61 (4) ◽  
pp. 979-984 ◽  
Author(s):  
E. R. C. van der Linde ◽  
D. D. Mara
Keyword(s):  
Nitrogen Removal ◽  
Organic Nitrogen ◽  
Pilot Scale ◽  
Hydraulic Characteristics ◽  
Dye Tracer ◽  
Waste Stabilization ◽  
Rhodamine Wt ◽  
The Uk ◽  
Initial Results ◽  
Experimental Runs

Nitrogen removal mechanisms and pathways within WSP have been the focus of much research over the last 30 years. Debates and theories postulated continue to refine our knowledge regarding the cycling and removal pathways for this important nutrient, but a succinct answer has yet to be provided for holistic nitrogen removal. In this study, two experimental runs using labelled 15N as a stable isotope tracking technique were conducted on a pilot-scale primary facultative WSP in the UK; one in the summer of 2006, and the other in the winter of 2007. An ammonium chloride (15NH4Cl) spike was prepared as the slug for each experimental run, which also contained rhodamine WT to act as a dye tracer enabling the hydraulic characteristics of the pond to be mapped. Initial results from the study are reported here, and findings are compared and contrasted. Preliminary findings reveal that a greater proportion of 15N is incorporated into the algal biomass by assimilation and subsequent release as soluble organic nitrogen in summer than in winter. 15N ammonium passes out of the system much sooner and in a much higher proportion in the winter than in summer.

scholarly journals The Error in Measuring an Accelerated Flow Velocity by a Spark Tracer Method

1981 ◽  
Vol 24 (193) ◽  
pp. 1168-1175 ◽  
Author(s):  
Kazuyasu MATSUO ◽  
Toshiaki SETOGUCHI ◽  
Yoshihisa YAMAMOTO
Keyword(s):  
Flow Velocity ◽  
Tracer Method ◽  
Accelerated Flow

Influence of Waterproof Wall in Approach Channel of Double-Line Ship Lock on Flow Condition

2014 ◽  
Vol 716-717 ◽  
pp. 347-350
Author(s):  
Jun Tao Li ◽  
Wei Peng
Keyword(s):  
Flow Velocity ◽  
Flow Condition ◽  
Second Line ◽  
Hydraulic Characteristics ◽  
Xiangjiang River ◽  
Double Line ◽  
Approach Channel ◽  
Lock In ◽  
Transverse Flow Velocity ◽  
Ship Lock

Unsteady flow during lock filling and emptying in approach channel of double-line ship lock is more complicated than that of single line ship lock. In this paper, by a 3-D numerical model, the water fluctuation inside approach channel under different arrangement types of waterproof wall and the hydraulic characteristics such as longitudinal flow velocity and transverse flow velocity were analyzed on the basis of the 2000t second-line ship lock construction project of Zhuzhou navigation power junction in Xiangjiang River. According to the separate arrangement scheme and the completely-connected arrangement scheme of approach channel, the flow condition problem may exist in the scheme was analyzed. In order to improve the ship navigation and berthing condition, it was proposed that the waterproof wall should be set between the approach channels of the second-line ship lock.

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