Numerical Modeling of the Dispersion Characteristics of Pollutants in the Confluence Area of an Asymmetrical River

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this paper, the pollutant transport and diffusion characteristics of asymmetric river channel intersection area are calculated by numerical simulation, and the pollutant mixing characteristics are analyzed in depth. The transport and diffusion of pollutants were studied in detail from the aspects of transverse, longitudinal and vertical. The objective of the article is clear and the research method is reasonable. The research results have practical guiding significance for the application of pollutant control and computational fluid dynamics in pollutant transport diffusion flow field. The manuscript, however, needs some additional revision.

1.In the summary section, lines 11-12, the discharge ratio and wide-depth ratio are hydrodynamic characteristics, but the concentration difference is not a hydrodynamic characteristic. It is recommended to remove hydrodynamic and directly use discharge ratio,wide-depth ratio, and concentration difference.

There is ambiguity in the description of the "differences in pollutants" in lines 18-19 of the abstract. Should it be the "difference in pollutant concentration"?

2. In the discussion part, the research object, research method and data analysis have been discussed in depth. In the data analysis discussion, some detailed data support can be added.

3.In addition, it is suggested to improve the quality of the pictures in the article.

4.There are instances of incorrect citation sources in some chapters of the article, and it is recommended to modify them.

 

Comments on the Quality of English Language

It is noted that your manuscript needs careful editing paying particular attention to English grammar, spelling, and sentence structure so that the goals and results of the study are clear to the reader.

Author Response

Dear Reviewer:

Thank you for your letter and for the comments concerning our manuscript entitled “Numerical modeling of the dispersion characteristics of pollutants in the confluence area of an asymmetrical river”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have to made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the comments are as flowing:

1.In the summary section, lines 11-12, the discharge ratio and wide-depth ratio are hydrodynamic characteristics, but the concentration difference is not a hydrodynamic characteristic. It is recommended to remove hydrodynamic and directly use discharge ratio, wide-depth ratio, and concentration difference.

There is ambiguity in the description of the "differences in pollutants" in lines 18-19 of the abstract. Should it be the "difference in pollutant concentration"?

Response: Thank you for your valuable comments. In the summary section, lines 11-12, combined with your suggestions, it is found that the discharge ratio and the width-depth ratio are hydrodynamic characteristics, and the concentration difference is not hydrodynamic characteristics. For this reason, we changed the “hydrodynamic condition” to the “inflow condition” according to your suggestion.

In lines 18-19, the “difference in pollutant” concentration is replaced by the “difference in pollutant concentration”.

2. In the discussion part, the research object, research method and data analysis have been discussed in depth. In the data analysis discussion, some detailed data support can be added.

Response: Thank you for your suggestion. In the discussion part, some detailed data support was added, specifically in lines 462-468

3.In addition, it is suggested to improve the quality of the pictures in the article.

Response: We apologize for the quality of the pictures submitted before. And all the pictures in the article have been re-exported from the original data. The figure quality has been significantly improved.

4.There are instances of incorrect citation sources in some chapters of the article, and it is recommended to modify them.

Response: We carefully examined the article citation sources and modified the incorrect citation sources. For example, individual reference sources such as 3 and 7 have been modified.

To sum up, we have carefully revised it according to the valuable opinions of experts. Please feel free to contact us if there are any question. Thanks again to the reviewer for your hard work! Best wishes to you!

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor

 

Comments on manuscript titled: “Numerical Modeling of the dispersion characteristics of pollutants in the confluence area of an asymmetrical river”

 

1.      Give gap analysis of this research and explain innovation of this research

2.      Check grammatically the text

3.      Number of Figs is unclear in the text, please check.

4.      Please explain about effect of the pollutants type on model results.

5.      How did you investigate the degradation, adsorption and absorption processes on the model?  

 

Comments on the Quality of English Language

Dear Editor

 

Comments on manuscript titled: “Numerical Modeling of the dispersion characteristics of pollutants in the confluence area of an asymmetrical river”

 

1.      Give gap analysis of this research and explain innovation of this research

2.      Check grammatically the text

3.      Number of Figs is unclear in the text, please check.

4.      Please explain about effect of the pollutants type on model results.

5.      How did you investigate the degradation, adsorption and absorption processes on the model?  

 

Author Response

Dear Reviewer:

Thank you for your letter and for the comments concerning our manuscript entitled “Numerical modeling of the dispersion characteristics of pollutants in the confluence area of an asymmetrical river”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have to made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the comments are as flowing:

1.Give gap analysis of this research and explain innovation of this research

Response: Thank you for your valuable comments. In the analysis of Chapter 5, we explain the innovation of this study, specifically in lines 445-453. The main conclusions are as follows: In this paper, a three-dimensional hydrodynamic water quality model is used to analyze the mixing law of vertical pollutants on the basis of predecessors. At the same time, the transport of pollutants under different flow conditions is analyzed more comprehensively.

2.Check grammatically the text

Response: The article has made major changes to English grammar, spelling, and sentence structure.

3.Number of Figs is unclear in the text, please check.

Response: This article carefully checked the serial number of graphics, and made changes.

4.Please explain about effect of the pollutants type on model results.

Response: This paper mainly examines persistent pollutants, which have little effect on the model results. Specifically, it is pointed out in line 204-206 in the text.

5. How did you investigate the degradation, adsorption and absorption processes on the model?

Response: This paper mainly examines the persistent pollutants, so this paper does not consider the degradation and adsorption process of the model for the time being. Illustrated in section 3.3.1, specifically in lines 206-207.

To sum up, we have carefully revised it according to the valuable opinions of experts. Please feel free to contact us if there are any question. Thanks again to the reviewer for your hard work! Best wishes to you!

Reviewer 3 Report

Comments and Suggestions for Authors

The paper is interesting but there are some rooms to improve

1. I can not see a methodology part to explain why these mathematical calcukations and formulas? It means that, after an introduction we can see control part and calculation. I can see as a reader you explained calculations and plots based on them. But why this method?

2. In design part authors try to provide some information but again the question is why this kind of design? 

3. I believe that some plots are redundant and you can combine some parts in just one table.

4. Conclusion part can not support your massive calculations. Even your discussion has not enough references about previous researches.

Author Response

Dear Reviewer:

Thank you for your letter and for the comments concerning our manuscript entitled “Numerical modeling of the dispersion characteristics of pollutants in the confluence area of an asymmetrical river”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have to made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the comments are as flowing:

1. I can not see a methodology part to explain why these mathematical calculations and formulas? It means that, after an introduction we can see control part and calculation. I can see as a reader you explained calculations and plots based on them. But why this method?

Response: Thank you for your valuable suggestions. The explanation of why to use this method is added in Chapter 2, specifically in lines 78-87. The main reason is that compared with the traditional physical model, the use of numerical simulation can save manpower and reduce the time cost.

2. In design part authors try to provide some information but again the question is why this kind of design?

Response: Thank you for your proposal. The reason for this design is added in Section 3.1, specifically in lines 207-212. The main reason is to investigate the influence of incoming flow factors on the diffusion of pollutants, and the incoming flow factors include confluence ratio, width-depth ratio and concentration difference. Therefore, this paper uses the control variable method to analyze and study.

3. I believe that some plots are redundant and you can combine some parts in just one table.

Response: Thank you for this suggestion. The structure of Section 4.1 is adjusted. Only a new schematic diagram is retained, redundant graphics are deleted, and some contents are merged into a table.

4. Conclusion part can not support your massive calculations. Even your discussion has not enough references about previous researches.

Response: Thank you for your valuable suggestions. In Chapter 5, specific data are added to analyze and discuss. Specifically in lines 462-468.

To sum up, we have carefully revised it according to the valuable opinions of experts. Please feel free to contact us if there are any question. Thanks again to the reviewer for your hard work! Best wishes to you!

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor,

All comments have been amended.

Regards

Reviewer 3 Report

Comments and Suggestions for Authors

The paper is accepted in current version.