Review Reports - A Multigrid Dynamic Bidirectional Coupled Surface Flow Routing Model for Flood Simulation

Round 1

Reviewer 1 Report

The authors developed a surface flow routing technique for simulating floods. The authors have developed a pretty good draft manuscript, providing a good technical write-up. Most of my comments are of an editorial nature. My comments addressing the technical and editorial of the revised paper are summarized in the attachement.

Comments for author File: Comments.pdf

Author Response

Responds to the reviewer’s comments:

First of all, sincerely thank you very much for your valuable comments. All your suggestions are very important, which have important guiding significance for our writing and scientific research work. When revising the article, we considered thoughtfully what you have said.

1.Comment: The reference citations are cited sequentially, in accordance with the author guidelines for the journal. However, the citations should be uniquely separated in their citation, and provide in brackets.

Response to comment: Thank you very much for your valuable suggestions earnestly.

We are so sorry that many references do not conform to the specifications of the Journal.

After reading your valuable suggestions carefully, we have revised the format of references, in accordance with the author guidelines for the journal.

Comment: p.2, par.1: This paragraph is very lengthy; I suggest breaking this paragraph into several shorter paragraphs.

Response to comment: Thank you for reading this article carefully and making valuable suggestions, and we learned a lot from your valuable comments. We have broken the paragraph 2 in p2 into two shorter paragraphs, in order to better help readers understand our manuscript. Thank you very much again.

Comment: The authors also describe various software models, which need to be briefly described. Examples are listed below:

(a) p.2, par.1: TOPMODEL; Mike Flood, SWAT, GEMESS, SHE

(b) p.2, par.2: TRIBS-OFM

(d) p.5, par.3: HLLC

(e) p.9, par.8: CCFV

(f) p.15, par.1: SWE

Response to comment: Thank you very much for your valuable comments. You're really careful. Your thoughtful suggestions have greatly improved our manuscript. We are sorry that some software models have not been described briefly in the original manuscript, and some software names have only abbreviations but not full names. After reading your comments, we have described the software models in the revised manuscript, which were also marked using red bold.

Moreover, more attention will be paid to similar problems in our future writing. And we hope that there won't be any similar problems next time. According to your valuable suggestions, we will greatly improve the abilities of scientific research and make more achievements in the future work.

Comment: Several of the numbers and their units need spacing between the numbers and the units.

Response to comment: Thank you very much for your valuable comments. You're really careful. Your suggestions have greatly improved our manuscript. We have revised the manuscript after reading the valuable comments, have left space between numbers and their units. And we have also used one of the editing services listed at https://www.mdpi.com/authors/english to check our manuscript, and the problems were also revised by the services of a good technical editor in MDPI. Thank you again for your valuable comments.

Comment: p.11, Figure 5 caption: The caption should be listed on the same page as the figure.

Response to comment: Thank you very much for your valuable suggestions earnestly. After reading your valuable comments, we have revised the manuscript. The caption was listed on the same page as the figure on the revised manuscript.

Comment: p.13, Figure 8 caption: The caption should be listed on the same page as the figure.

Response to comment: Thank you for reading this article carefully and making valuable suggestions. After reading your valuable comments, we have revised the manuscript. The caption was listed on the same page as the figure on the revised manuscript.

What’s more, we have also checked other figures and tables in the original manuscript to ensure that the caption was listed on the same page as the figure or table.

Comment: p.11, par.1: The authors provide some of the characteristics in the domain. So what? Significance? Implications?

Response to comment: Thank you for reading this article carefully and making valuable suggestions, which greatly improved and perfected our manuscript. When simulating rainfall runoff over a watershed using M-DBCM, a lot of data information was needed, such as Manning’s coefficient, bed slope, the length and width of the watershed and so on. And therefore, we have described the characteristics of the domain in order to simulate the rainfall runoff using the proposed model. We will be really grateful that if you give us more valuable advices again. Look forward to hear from you.

Comment: (8) p.14, par.1: The authors provide some of the characteristics in the domain. So what? Significance? Implications?

Comment: There are line spacing problems in the discussions following equations. Examples include:

(a) p.4, par.5, lines 6 – 8

(b) p.5, par.1, lines 2 – 4

(d) p.6, par.1, lines 7 – 10

(e) p.6, par.2, lines 11 – 13

(f) p.7, par.2, lines 9 – 12

(g) p.8, par.1, lines 3 – 5

(h) p.10, par.6, lines 9 – 12

Response to comment: Sincerely thank you for your careful reading and valuable comments. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. The line spacing in equations in the original manuscript was rearranged in the revised manuscript.

Comment: There are a number of minor editorial revisions that need to be corrected/revised.

Response to comment: Thank you for reading this article carefully and making valuable suggestions. We are so sorry that our English was not well. We have employed the services of a good technical editor in MDPI to improve the use of English and grammar in the manuscript.

Comment: The authors would be well advised to employ the services of a good technical editor to improve the use of English and grammar in the manuscript.

Response to comment: As you pointed, English revision was necessary. There are a number of problems that need to be corrected/revised. After reading your valuable comments, we have employed the services of a good technical editor in MDPI to improve the use of English and grammar in the manuscript.

Comment: There are several issues related to the reference citations on pages 26–27 that require clarification:

(a) Be consistent in the citing of article titles; only capitalize the first word of the article, or capitalize all important words.

(b) Several references only list one page in the citation; see reference Nos.1, 16, and 21.

Response to comment: Thank you for reading this article carefully and making valuable suggestions. We modified the citing of article titles in references, and made the titles of all cited references consistent. What’s more, we are really sorry that several references only list one page in the citation. After reading your valuable comments, we have consulted these references again and the page numbers of these references have been revised. Furthermore, Reference Nos. 31 and 22 were cited in the body of the manuscript.

And we have also revised the format of other references and whether they were cited in the manuscript. We promise not to make such mistakes next time.

Sincerely special thanks to you for your good comments again. All your comments are very important, which have important guiding significance for our writing and scientific research work. Because of your valuable suggestions, we found some shortcomings in our current work. We will improve the abilities of scientific research and make more achievements according to your valuable suggestions in the future work. And we devotedly wish that we can learn more from you.

Once again, thank the respected editors and reviewers for their patient reading and valuable comments. We have learned a lot from your valuable suggestions. If you have any question about this paper, please don’t hesitate to let us know. Thank you very much for all your help and looking forward to hearing from you soon.

Best regards.

Yours sincerely,

Yanxia Shen

Reviewer 2 Report

The study makes use of a multigrid dynamic bidirectional coupled surface flow routing model to improve calculation efficiency while trying at the same time to maintain accuracy. The study is characterized by a solid scientific soundness and quality of presentation. It is obvious that the authors are doing in-depth work characterized by maturity on the subject. The background is adequately described. The objective is very clear .
Only minor amendments/improvements are in order in my opinion:

- The authors although they do a good job in describing their objective in the last paragraph of Introduction section, they have not described clearly for the reader why this study has added value. I would suggest to add 1-2 sentences in the last part of Introduction to highlight the merits of their approach.
- The authors present the results and conclusions in a complete and very clear / high quality manner. However, there is no discussion of the results whatsoever. I would suggest that adding a discussion, comparing the results with the ones of other studies, other approaches or other efforts in the same field would benefit the manuscript. In addition, I would suggest to discuss the findings in terms of added value and practical implications.

Author Response

1. Comment: The authors although they do a good job in describing their objective in the last paragraph of Introduction section, they have not described clearly for the reader why this study has added value. I would suggest to add 1-2 sentences in the last part of Introduction to highlight the merits of their approach.

Response to comment: Thank you very much for your valuable suggestions earnestly. As you pointed, the merits of our research were not described clearly in Introduction section of the original manuscript. We can’t agree with you more. After reading your valuable suggestions carefully, we have revised the Introduction, and the limitations of each existing study mentioned in the references and the merits of this study to overcome them have also been emphasized. If you want to learn more about the merits of the method proposed in our study, you can review this in the section Introduction of the revised manuscript, which were marked using red bold.

2. Comment: The authors present the results and conclusions in a complete and very clear / high quality manner. However, there is no discussion of the results whatsoever. I would suggest that adding a discussion, comparing the results with the ones of other studies, other approaches or other efforts in the same field would benefit the manuscript. In addition, I would suggest to discuss the findings in terms of added value and practical implications.

Response to comment: Thank you for reading this article carefully and making valuable suggestions, and we learned a lot from your valuable comments. In order to verify the performance of the M-DBCM and highlight the added value of the proposed model, the Section 3 (Applications and discussions) have been divided into “Applications” and “Discussions” in the revised manuscript, and the results were further analyzed. Moreover, to quantify the performance of the model, the Root Mean Square Error (RMSE) was used to measure the error of the proposed model, and the results were also compared with the CASC2D and the model proposed by Yu and Duan. If you want to learn more about this, you can review this in the section of Discussions of the revised manuscript, which were marked using red bold in the revised manuscript. We will be really grateful that if you give us valuable advices again. Your valuable suggestions can not only improve our original manuscript, but also facilitate our future research and writing. Thank you very much again.

Finally, special thanks to you for your good comments again. Because of your valuable suggestions, we found some shortcomings in our original manuscript. Through your comments, we identified the shortcomings of our original paper and further perfected our research. We will improve the abilities of scientific research and make more achievements according to your suggestions in the future work. And we sincerely hope that we can learn more from you.

Reviewer 3 Report

The title of this paper is “A multigrid dynamic bidirectional coupled surface flow routing model for flood simulation”. The title of this paper is interesting. However, the contents of this paper needs a revision for publication in Water.

Comments for author File: Comments.pdf

Author Response

First of all, thank you very much for your valuable comments. All your suggestions are very important, which have important guiding significance for our writing and scientific research work. When revising the original manuscript, we considered carefully what you have said. After reading your considerable comments, we have made a major revision based on the original manuscript, especially the introduction and discussions, which we hope meet with approval. Next, we will give you one by one response to your comments.

1. Comment: In Introduction, the format of the references should be modified to match the format of Water.

Response to comment: Thank you very much for your valuable comments. You're really careful. Your thoughtful suggestions have greatly improved our manuscript. We are not cognizant of the problem before reading your considerable suggestions. We have modified the format of the references to match the format of Water.

2. Comment: In Introduction, one paragraph is too long. Paragraph division is required to increase readability.

Response to comment: Thank you very much for your valuable comments. You're really careful. Your suggestions have greatly improved our manuscript. As you pointed, one paragraph is too long in Introduction of the original manuscript. After reading your careful comments, we have divided the Introduction into several paragraphs to increase readability. And different contents were described in each paragraph, which can help readers better understand the value of our study.

3. Comment: In Introduction, the limitations of each existing study mentioned in the references and the merits of this study to overcome them should be emphasized.

Response to comment: Thank you very much for your valuable suggestions earnestly. We are really sorry that the limitations of the existing model were not described clearly in the original manuscript. After reading your valuable comments carefully, we have reviewed a lot of literatures about flood simulation model, and the disadvantage of each existing study mentioned in the references were demonstrated, and furthermore, the methods applied in this study were compared with previous research to justify the value of this new method. If you are interested, you can review it in the Section of Introduction in the revised manuscript, which were highlighted in red bold. We will really appreciate it if you give us more considerable comments again. We are glad to hear from you.

4. Comment: Section 3 (Applications and discussions) should be divided into “Applications” and “Discussions”.

Response to comment: Thank you for reading this article carefully and making valuable suggestions. The Section 3 (Applications and discussions) have been divided into “Applications” and “Discussions” in the revised manuscript to help readers better understand the paper, according to your considerable suggestions. If you want to learn more about this, you can review this in the Sections 3 and 4 of the revised manuscript, which was also highlighted using red bold. And we will really appreciate it if you give us more considerable comments again.

5. Comment: In Figure 13, the differences between methods are not clear, so it is necessary to enlarge the main parts.

Response to comment: Thank you for reading this article carefully and making valuable suggestions, which greatly improved and perfected our manuscript. In our research, the M-DBCM, DBCM and 2D full hydrodynamic model were all used to simulate the runoff over the V-shaped catchment under same conditions, and the discharge hydrographs obtained from different models were really close, which indicates that the M-DBCM proposed in this paper has good performance. However, there is a slight difference in the discharge receding limb and rising limb, so the discharge receding limb and rising limb obtained from different models were enlarged in the revised manuscript. If you are interested about this, you can review this in Figures 13(b) and 13(c). We will be really grateful that if you give us more valuable advices again. Look forward to hear from you.

6. Comment: The title of Table 1 is written twice.

Response to comment: Thank you very much for your valuable comments. You're really careful. Your thoughtful suggestions have greatly improved our manuscript. We are so sorry that the title of Table 1 was written twice because of our carelessness. We have modified the title of Table 1 in the revised manuscript. Besides, we also checked other tables in original manuscript to determine whether other tables have the same problem.

7. Comment: In Figure 20, to quantify the error by each method, it is necessary to apply error measurement methods such as MAE based on absolute values and RMSE based on square values.

Response to comment: Sincerely thank you for your careful reading and valuable comments. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. As you mentioned, it is necessary to apply error measurement methods to quantify the error of each method. We have calculated the RMSE of M-DBCM and 2D full hydrodynamic model, and the results were compared with the CASC2D and a model proposed by Yu and Duan. If you interested, you can learn it from lines 615 to 636 in revised manuscript, which were also highlighted using red bold. We will be really grateful that if you give us valuable advices again.

8. Comment: In Conclusion, it is necessary to mention the limitations of this study and subsequent studies to overcome them.

Response to comment: Thank you for reading this article carefully and making valuable suggestions. It is well-known that each method has its advantages and disadvantages, and there is no perfect model. We are so sorry that we have not described the limitations of the model proposed in this paper clearly. After reading your considerable comments, the shortcomings of the model proposed were described, and the follow-up research direction was also identified in Conclusions of the revised manuscript. If you want to learn more about this, you can review this from lines 761 to 767 in the revised manuscript. Thank you very much for your valuable comments again. We learn more from your valuable suggestions, which is very helpful for our future writing and research.

Round 2

Reviewer 3 Report

The title of this paper is “A multigrid dynamic bidirectional coupled surface flow routing model for flood simulation”. All the comments I pointed out were faithfully revised in this paper. Therefore, I recommend an acceptance in this paper.

Comments for author File: Comments.pdf

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.