Three-Dimensional Hole Size (3DHS) Approach for Water Flow Turbulence Analysis over Emerging Sand Bars: Flume-Scale Experiments
, Nayan Sharma 2, Giuseppe Francesco Cesare Lama 3,*, Murtaza Hasan 4, Rishav Garg 1, Gianluigi Busico 5 and Raied Saad Alharbi 6
Round 1
Reviewer 1 Report
The author has revised the article and suggested the author to improve the clarity of the graph.
Author Response
REVIEWER 1
R = Reviewer; A = Answer to the reviewer
R = The author has revised the article and suggested the author to improve the clarity of the graph.
A = Thank you very much for your suggestion. The quality of all figures has been properly improved, and the legends were re-arranged in order to satisfy the valuable suggestion of the reviewer.
Reviewer 2 Report
The present paper entitled ” Three-Dimensional Hole Size (3DHS) Approach for Water Flow Turbulence Analysis over Emerging Sand Bars: Flume- Scale Experiment” deals with the measurement 3D velocity fields were measured through an acoustic Doppler velocimeter during flume-scale laboratory experimental runs over an emerging sand bar model, to reproduce the hydrodynamic conditions of real braided.
The document is interesting, but some appreciations are made by this reviewer.
Abstract. This section is well described, particularly the novelty of the project is well presented
Introduction. A review of the state of the art is depicted in this session, together with the main objectives of the research.
Materials and Methods section is well presented, with the description of the experiment and main results. In a formal aspect, legend of the figures are too long, in this reviewer opinion, they should be part of the text.
In this reviewer opinion, authors should indicate if the main objectives have been accomplished.
Conclusions. In this reviewer opinion, conclusions should not be only a resume, but also some clear statements with the main achievements and novelty of the research.
Author Response
REVIEWER 2
R = Reviewer; A = Answer to the reviewer
R = The present paper entitled “Three-Dimensional Hole Size (3DHS) Approach for Water Flow Turbulence Analysis over Emerging Sand Bars: Flume- Scale Experiment” deals with the measurement 3D velocity fields were measured through an acoustic Doppler velocimeter during flume-scale laboratory experimental runs over an emerging sand bar model, to reproduce the hydrodynamic conditions of real braided.
The document is interesting, but some appreciations are made by this reviewer.
A = Thank you very much for your suggestion.
R = Abstract. This section is well described, particularly the novelty of the project is well presented
A = Thank you very much for your suggestion.
R = Introduction. A review of the state of the art is depicted in this section, together with the main objectives of the research.
A = Thank you very much for your suggestion.
R = Materials and Methods section is well presented, with the description of the experiment and main results. In a formal aspect, legend of the figures is too long, in this reviewer opinion, they should be part of the text.
A = Thank you very much for your suggestion. The quality of all figures has been properly improved, and the legends were re-arranged in order to satisfy the valuable suggestion of the reviewer.
R = In this reviewer opinion, authors should indicate if the main objectives have been accomplished.
A = Thank you very much for your suggestion. As reported in the text “The main goal of furnishing a useful and simple tool for both hydrodynamic and environmental researchers for the analysis of 3D turbulence over braided rivers was accomplished through the present flume-scale experimental study.”
R = Conclusions. In this reviewer opinion, conclusions should not be only a resume, but also some clear statements with the main achievements and novelty of the research.
A = Thank you very much for your suggestion. As reported in the text “The main goal of furnishing a useful and simple tool for both hydrodynamic and environmental researchers for the analysis of 3D turbulence over braided rivers was accomplished through the present flume-scale experimental study.”
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The study is valuable in addressing the issue of how braided streams originate and develop.
However, this study is limited to presenting the measurement results of turbulence intensities and octagonal bursting events. Therefore, further examination of the reliability of the measurement results, together with the hydrodynamic considerations, is necessary.
The present referee would like to raise the following questions and comments.
1. Line 59
The reference, Kirchner et al. [38], is missing. Instead, another paper by the present authors is introduced.
2. Figure 1
Figure 1 gives the emerging bar and the measuring grid. But the figure is not prepared to clearly show their positional relationship. It is necessary to show the origin of and the coordinate axes.
3. Line 79
Adjustment of the x-direction of the ADV device to the main flow direction is vital to ensure the accuracy of ADV. The explanation of how the authors minimize the influence of the installation error of ADV on the y- and z-direction components is welcome.
4. Lines 92 and 93, Figure 1, and Table 1
The measuring grid has a 10 cm spacing. However, in Table 1, the major dimension of the sandbar is 130 cm. Therefore, the grid shown in Figure 1 cannot cover the entire sandbar. Thus, the sizes of the sandbars listed in Table 1 seem to be incorrect. Also, the symbols l and b are listed interchangeably.
5. Figure 2
The classification P1 to P8 is more understandable in the form of a table, not a figure.
6. Line 148
The root-mean-square of velocity fluctuation should be written correctly.
7. Figure 3 to Figure 7
The definition of the symbol L is missing. It is essential to clarify the positional relationship between the origins of the x-axis and y-axis and the model bar. The scale and color of the legend bars should be the same for all figures in order to facilitate comparisons among figures (a), (b), and (c), as well as between Figure 4 and Figure 5.
8. Figure 3
Why does Figure 3 show complicated distributions of the turbulent intensities in the absence of a bar? The reliability of the experiment is questionable. The present referee would like to confirm the mean velocity distributions and the river bed topography.
9. Figure 4
Is the island-like pattern in Figure 4 (c) reasonable? Explain how the island-like shape can be produced.
10. Figure 8 to Figure 11
The scale and color of the legend should be the same for all figures. What value of 3DHS is best to analyze the bursting phenomenon based on this study?
11. Line 235 to Line 238
The hydrodynamic meaning of the relation between the probabilities of octagonal bursting events and the measurement position around the bar is unexplained.
12. Overall
During the experiment, local scouring around the bar and sediment deposition may have occurred. How do you tell the influence of the bar's existence and the river bed change on the bursting events?
Author Response
REVIEWER 1
R = Reviewer; A = Answer to the reviewer
R = The study is valuable in addressing the issue of how braided streams originate and develop However, this study is limited to presenting the measurement results of turbulence intensities and octagonal bursting events. Therefore, further examination of the reliability of the measurement results, together with the hydrodynamic considerations, is necessary. The present referee would like to raise the following questions and comments.
A = Thank you very much for your precious suggestion. We really appreciate that the scientific message of the article was well acknowledged by the reviewer.
R = Line 59: The reference, Kirchner et al. [38], is missing. Instead, another paper by the present authors is introduced.
A = Thank you very much for your precious suggestion. The issue has been fixed in the text.
R = Figure 1 gives the emerging bar and the measuring grid. But the figure is not prepared to clearly show their positional relationship. It is necessary to show the origin of and the coordinate axes.
A = Thank you very much for your precious suggestion. The issues have been fixed in the text:
“The depth-averaged contour maps of TKE components over x, y, and z directions are shown in detail in Figure 3, Figure 4, Figure 5, Figure 6, and Figure 7 for the experimental runs 1R, 2R, 4R, 6R, and 10R, respectively. In all Figures, L is the total extension of the reference grid, while the origin of the x and y axes is located at the bar bottom, at its centre”.
R = Line 79: Adjustment of the x-direction of the ADV device to the main flow direction is vital to ensure the accuracy of ADV. The explanation of how the authors minimize the influence of the installation error of ADV on the y- and z-direction components is welcome.
A = Thank you very much for your precious suggestion. The issues have been fixed in the text:
“As shown in Figure 1, the experimental runs were carried out in a 3 m wide, 1 m deep, and 12 m long concrete flume located in the River Engineering Laboratory of the Department of Water Resources Development and Management at the Roorkee Indian Institute of Technology (India), under constant bed slope and discharge values of 0.005 and 0.25 m3 s-1, respectively. The x direction corresponds to the water flow direction”.
R = Lines 92 and 93, Figure 1, and Table 1: The measuring grid has a 10 cm spacing. However, in Table 1, the major dimension of the sandbar is 130 cm. Therefore, the grid shown in Figure 1 cannot cover the entire sandbar. Thus, the sizes of the sandbars listed in Table 1 seem to be incorrect. Also, the symbols l and b are listed interchangeably.
A = Thank you very much for your precious suggestion. The issues have been fixed in the text.
R = Figure 2: The classification P1 to P8 is more understandable in the form of a table, not a figure.
A = Thank you very much for your precious suggestion. Too many articles with tables on P1 to P8 have been already published in WATER JOURNAL MDPI, then the Figure is undoubtedly more appropriate.
R = Figure 3 to Figure 7: The definition of the symbol L is missing. It is essential to clarify the positional relationship between the origins of the x-axis and y-axis and the model bar. The scale and color of the legend bars should be the same for all figures to facilitate comparisons among figures (a), (b), and (c), as well as between Figure 4 and Figure 5.
A = Thank you very much for your precious suggestion. The issues have been fixed in the text:
“The depth-averaged contour maps of TKE components over x, y, and z directions are shown in detail in Figure 3, Figure 4, Figure 5, Figure 6, and Figure 7 for the experimental runs 1R, 2R, 4R, 6R, and 10R, respectively. In all Figures, L is total extension of the reference grid, while the origin of the x and y axes is located at the bar bottom, at its centre”.
The scale and colour of the legends are obtained directly from the Origin freeware software.
R = Why does Figure 3 show complicated distributions of the turbulent intensities in the absence of a bar? The reliability of the experiment is questionable. The present referee would like to confirm the mean velocity distributions and the riverbed topography.
A = Thank you very much for your precious suggestion. All the results have been double-checked, and we can confirm that the cross-sectional turbulence distributions are correct.
R = Is the island-like pattern in Figure 4 (c) reasonable? Explain how the island-like shape can be produced.
A = Thank you very much for your precious suggestion. All the contour maps have been obtained by employing the freeware Origin software. Thus, they have been discussed starting from the interpolation results.
R = Figure 8 to Figure 11 - The scale and color of the legend should be the same for all figures. What value of 3DHS is best to analyze the bursting phenomenon based on this study?
A = Thank you very much for your precious suggestion. The scale and colour of the legends are obtained directly from the Origin freeware software. The 3DHS analysis was proposed to understand if it could be considered as a useful tool for the analysis of 3D turbulence at emerging sand bars. Further analyses will focus on more detailed studies on advanced CFD approaches.
R = Line 235 to Line 238 - The hydrodynamic meaning of the relation between the probabilities of octagonal bursting events and the measurement position around the bar is unexplained.
A = Thank you very much for your precious suggestion. The 3D octagonal analysis was proposed to understand if it could be considered as a useful tool for the analysis of 3D turbulence at emerging sand bars. Further analyses will focus on more detailed studies on advanced CFD approaches.
R = Overall: During the experiment, local scouring around the bar and sediment deposition may have occurred. How do you tell the influence of the bar's existence and the riverbed change on the bursting events?
A = Thank you very much for your precious suggestion. These findings will be discussed in more detail in further advanced studies.
Reviewer 2 Report
The authors have presented a three dimensional hole size approach for analyzing the turbulent water flow over emerging sand bars. The paper is relevant to the journal. It is interesting and reasonably well written. I can recommend publication of the paper after a minor revision.
(1) The introduction is very weak. The authors could bring in some more discussion on the novelty of the present work.
(2) The authors should include a nomenclature with all the symbols and abbreviation used in the paper. It will be very useful to the reviewers and readers.
Author Response
REVIEWER 2
R = Reviewer; A = Answer to the reviewer
The authors have presented a three-dimensional hole size approach for analyzing the turbulent water flow over emerging sand bars. The paper is relevant to the journal. It is interesting and reasonably well written. I can recommend the publication of the paper after a minor revision.
A = Thank you very much for your precious suggestion. We really appreciate that the scientific message of the article was well acknowledged by the reviewer.
R = The introduction is very weak. The authors could bring in some more discussion on the novelty of the present work.
A = Thank you very much for your precious suggestion. The article presents a new approach for the analysis of the 3D turbulence structures. For this reason, the introduction was not pompous.
Reviewer 3 Report
The present paper “Three-Dimensional Hole Size (3DHS) Approach for Water Flow Turbulence Analysis over Emerging Sand Bars: Flume- Scale Experiments” deals with , the 3D velocity fields were measured through an acoustic Doppler velocimeter during flume-scale laboratory experimental runs over an emerging sand bar model, to reproduce the hydrodynamic conditions of real braided river.
This is an interesting topic and related to the scope of the Journal. Nevertheless, some observations are proposed by this reviewer.
Abstract. This part is well presented, depicting the main achievements of the described research. Even the novelty of the work is here described. In this reviewer opinion, abstract is adequate as it is.
- This section is also well presented, introducing the state of the art with adequate references, and indicating the main objectives (goals) presented in the document
- Materials and Methods. Laboratory experiments are described in this section, including laboratory description and instrumentation. Methods, equations and probability proposals are well described in this section
- . Results and discussion. Results are well presented in the figures at the different experimental runs provided in the research, together with the three dimensional hole size in different cases. In general terms, results are adequate to the experimental research, but in this reviewer opinon, legend of figures are too long (this information should be part of the text) and some more comments to the huge information provided in the analysis would be also welcome in this section.
- Section 4 is missing
- This section is well stated, indicating the achievement of objectives, resume and novelty of the research
Author Response
REVIEWER 3
R = Reviewer; A = Answer to the reviewer
R = The present paper “Three-Dimensional Hole Size (3DHS) Approach for Water Flow Turbulence Analysis over Emerging Sand Bars: Flume-Scale Experiments” deals with the 3D velocity fields were measured through an acoustic Doppler velocimeter during flume-scale laboratory experimental runs over an emerging sand bar model, to reproduce the hydrodynamic conditions of real braided river. This is an interesting topic and related to the scope of the Journal. Nevertheless, some observations are proposed by this reviewer.
A = Thank you very much for your precious suggestion. We really appreciate that the scientific message of the article was well acknowledged by the reviewer.
R = Abstract: This part is well presented, depicting the main achievements of the described research. Even the novelty of the work is here described. In this reviewer's opinion, the abstract is adequate as it is.
A = Thank you very much for your precious suggestion. We really appreciate that the scientific message of the abstract was well acknowledged by the reviewer.
R = This section is also well presented, introducing the state of the art with adequate references, and indicating the main objectives (goals) presented in the document.
A = Thank you very much for your precious suggestion. We really appreciate that the scientific message of the INTRODUCTION was well acknowledged by the reviewer.
R = Materials and Methods: Laboratory experiments are described in this section, including laboratory description and instrumentation. Methods, equations, and probability proposals are well described in this section.
A = Thank you very much for your precious suggestion. We really appreciate that the scientific message of the MATERIAL AND METHODS was well acknowledged by the reviewer.
R = Results and discussion. Results are well presented in the figures at the different experimental runs provided in the research, together with the three-dimensional hole size in different cases. In general terms, the results are adequate for the experimental research, but in this reviewer's opinion, the legends of figures are too long (this information should be part of the text) and some more comments on the huge information provided in the analysis would be also welcome in this section.
A = Thank you very much for your precious suggestion. This section has been improved by furnishing more references:
- Yunping, Y.; Jinhai, Z.; Mingjin, Z.; Lingling, Z.; Yude, Z.; Jianjun, W.; Weiyang, Z. Sandy riverbed shoal under anthro-pogenic activities: The sandy reach of the Yangtze River, China. J. Hydrol. 2021, 603, 126861, https://doi.org/10.1016/j.jhydrol.2021.126861.
- Manna, M.; Vacca, A.; Verzicco, R. Reverse transition of a turbulent spiral Poiseuille flow at $Ta=1500$. J. Fluid Mech. 2022, 941, A6, doi:10.1017/jfm.2022.273.
- Yunping, Y.; Jinhai, Z.; Huaqing, Z.; Yuanfang, C.; Yude, Z.; Chenyang, W. Impact of the Three Gorges Dam on riverbed scour and siltation of the middle reaches of the Yangtze River. Earth Surf. Process. Landf. 2022, 209, 1–18, https://doi.org/10.1002/esp.5332.
R = Section 4 is missing.
A = Thank you very much for your precious suggestion. This issue has been fixed in the current version of the manuscript.
R = This section is well stated, indicating the achievement of objectives, resume, and novelty of the research.
A = Thank you very much for your precious suggestion. We really appreciate that the scientific message of the CONCLUSIONS was well acknowledged by the reviewer.
Reviewer 4 Report
- The author's research is of great significance and value, but the summary of the preface is still insufficient.
- It is suggested to add corresponding references: 1. Yang Yunping, Zheng Jinhai, Zhang Mingjin, Zhu Lingling, Zhhu Yude, Wang Jianjun, Zhao Weiyang. Sandy riverbed shoal under anthropogenic activities: The sandy reach of the Yangtze River, China [J]. Journal of Hydrology, 2021, 603: 2. Yang Yunping, Zheng Jinhai, Zhang Huaqing, Chai Yuanfang, Zhu Yude, Wang Chenyang. Impact of the Three Gorges Dam on riverbed scour and siltation of the middle reaches of the Yangtze River [J]. Earth Surface Processes and Landforms, 209:1-18.It could be another research paper.
- It is suggested that the author add a section to supplement the relationship between the results of this study and the evolution of braided rivers.
Author Response
REVIEWER 4
R = Reviewer; A = Answer to the reviewer
R = The authors’ research is of great significance and value, but the summary of the preface is still insufficient. It is suggested to add corresponding references:
Yang Yunping, Zheng Jinhai, Zhang Mingjin, Zhu Lingling, Zhhu Yude, Wang Jianjun, Zhao Weiyang. Sandy riverbed shoal under anthropogenic activities: The sandy reach of the Yangtze River, China [J]. Journal of Hydrology, 2021, 603, 126861.
Yang Yunping, Zheng Jinhai, Zhang Huaqing, Chai Yuanfang, Zhu Yude, Wang Chenyang. Impact of the Three Gorges Dam on riverbed scour and siltation of the middle reaches of the Yangtze River [J]. Earth Surface Processes and Landforms, 209, 1-18.
A = Thank you very much for your precious suggestion. Both references have been added in the revised version of the manuscript.
R = It is suggested that the author add a section to supplement the relationship between the results of this study and the evolution of braided rivers.
A = Thank you very much for your precious suggestion. This section has been improved by furnishing more references:
- Yunping, Y.; Jinhai, Z.; Mingjin, Z.; Lingling, Z.; Yude, Z.; Jianjun, W.; Weiyang, Z. Sandy riverbed shoal under anthro-pogenic activities: The sandy reach of the Yangtze River, China. J. Hydrol. 2021, 603, 126861, https://doi.org/10.1016/j.jhydrol.2021.126861.
- Manna, M.; Vacca, A.; Verzicco, R. Reverse transition of a turbulent spiral Poiseuille flow at $Ta=1500$. J. Fluid Mech. 2022, 941, A6, doi:10.1017/jfm.2022.273.
- Yunping, Y.; Jinhai, Z.; Huaqing, Z.; Yuanfang, C.; Yude, Z.; Chenyang, W. Impact of the Three Gorges Dam on riverbed scour and siltation of the middle reaches of the Yangtze River. Earth Surf. Process. Landf. 2022, 209, 1–18, https://doi.org/10.1002/esp.5332.
Round 2
Reviewer 1 Report
The authors made corrections in notation and additional explanations to make the manuscript legible. However, improvements still need to enhance the quality of the study.
- The classification P1 to P8 is better shown in the form of a table as adopted in many papers．Figure 2 occupies a large space with small amount of information.
- The scale and color of the legend bars should be the same for all figures to facilitate relevant comparisons among the figures. This helps readers efficiently understand the experimental results. The outputs from the software should be processed in a better way for readers.
- Reliability is a crucial point for experiments. The authors should show the obtained results are free from errors relating to the experimental flume and measuring devices. Hence the authors should discuss the interrelations between the turbulence intensities and bursting phenomena with mean velocity fields and bed topography.
4. The effects of sediment transport and the change in bed form on the experimental results cannot be overlooked. However, there is no description about them.
Author Response
Thank you very much for your precious time. Wr really appreciate the reviewers' suggestion, as the support of the three other reviewers that immediately accepted all corrections.
R = Reviewer; A = Answer to the reviewer
R = The classification P1 to P8 is better shown in the form of a table as adopted in many papers．Figure 2 occupies a large space with small amount of information.
A = Thank you very much for your precious suggestion. Too many articles with tables on P1 to P8 have been already published in WATER JOURNAL MDPI, then the Figure is undoubtedly more appropriate. We agree with the other 3 reviewers that the issue has been fixed properly.
R = The scale and color of the legend bars should be the same for all figures to facilitate relevant comparisons among the figures. This helps readers efficiently understand the experimental results. The outputs from the software should be processed in a better way for readers.
A = Thank you very much for your precious suggestion. The scale and colour of the legends are obtained directly from the Origin freeware software. We agree with the other 3 reviewers that the issue has been fixed properly.
R = Reliability is a crucial point for experiments. The authors should show the obtained results are free from errors relating to the experimental flume and measuring devices. Hence the authors should discuss the interrelations between the turbulence intensities and bursting phenomena with mean velocity fields and bed topography.
A = Thank you very much for your precious suggestion. All the results have been double-checked, and we can confirm that the cross-sectional turbulence distributions are correct. We agree with the other 3 reviewers that the issue has been fixed properly.
R = The effects of sediment transport and the change in bed form on the experimental results cannot be overlooked. However, there is no description about them.
A = Thank you very much for your precious suggestion. These findings will be discussed in more detail in further advanced studies. We agree with the other 3 reviewers that the issue has been fixed properly.
Author Response File: 
Author Response.docx
