3D Hydrodynamic Modelling Enhances the Design of Tendaho Dam Spillway, Ethiopia

Round 1

Reviewer 1 Report

Please find my comments in the attached PDF.

Comments for author File: Comments.pdf

Author Response

Dear Reviewers

Thank you very much for your valuable comments. We have addressed all the comments and responded accordingly below each comment. We have also indicated where in the manuscript the changes are made. We have added one new Figure which show location map. Since the manuscript is modified, we have added also the modified file.

The review comments have helped us improve our manuscript.

Thank you very much

Authors

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors and Editor,

Thanks for your kind invitation to review the manuscript entitled “Cheek of Spillway Safety Using State of the Art 3D Model a Case Study of Tendaho Dam Spillway, Ethiopia” by Getnet Kebede Demeke, Dereje Hailu Asfaw and Yilma Seleshi Shiferaw.

In this document, a three-dimensional model of the spillway of the Tendaho Dam in Ethiopia is established. The software (Flow 3D) is used, which solves the Navier-Stockes equations by finite volumes, and it is also compared with a classic 1D model (HEC-RAS) that solve the Saint-Venant equations based on integrating the velocity profile and the cross sections, resulting in a one-dimensional model

In my opinion there is a good background work, but I think there are important voids in how this research is presented. There are lacks of substance, mainly of methodological presentation, and formal, especially in the conclusions part. Finally I recommend the publication of this paper once the above issues have been resolved. Below are my suggestions that can be addressed as a Major Revision:

1. It is not clear what are the objectives of the work, an exclusive research for this spillway or broader objectives of how to define, calibrate, validate and compare a three-dimensional model through software. In the final part of the introduction, the objectives of the work must be established very explicitly and clearly. A brief summary of the structure and content of the document should also be presented.

2. The introduction should give a broader view of the state of the art at the present time. For example, this research uses Eulerian methods that are fixed in control sections, but currently, the research of hydraulic structures are having great success Lagrangian models that are fixed in the movement of fluid particles.

3. In my opinion, the main content of the "2.Background" section is a description of a case study. Therefore I think it should be the last subsection of the Materials and Methods section.

4. The methodological section describes the equations on which the 3D model is based, but another subsection describing the mathematical model 1D and the simplification of the equations that integrates the velocity profile would be necessary.

5. In the methodological section or in discussion it should comment on the differences that exist between the three dimensions of space. In this case, the longitudinal dimension (x) is much larger than the other two. What effects does it have on the numerical calculation by comparing the 3D and 1D models.

6. An explanatory figure with 3D discretization would be good to better understand the 3D model with respect to the cross-sectional 1D profiles.

7. It is expected that in the bend stretch there are relevant differences between the two models. More information about this section would be needed, with a cross-sectional comparison between the two models.

8. Regarding the hydraulic jump, nothing is said. For example, where is it located for different flow rates, how much energy dissipates, differences between models, etc.

9. There is no conclusions section. I wonder about the recommendations section to whom it is addressed? It looks like a project. I think there should be a section of clear and concise conclusions not of local scope. They should be useful for any case of spillways, and also focus on methodological conclusions useful to a broad sector of readers interested in hydraulic.

10. You must pass the dictionary tool and a language revision. e.g. “turbulunce”, “practicaly”

Kind regards

Author Response

Dear Reviewers

Thank you very much for your valuable comments. We have addressed all the comments and responded accordingly below each comment. We have also indicated where in the manuscript the changes are made. We have added one new Figure which show location map. Since the manuscript is modified, we have added also the modified file.

The review comments have helped us improve our manuscript.

Thank you very much

Authors

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Please find my comments in the PDF.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer

Thank you very much for your valuable comments. We have addressed all the comments and responded accordingly below each comment. We have also indicated where in the manuscript the changes are made. We have added supporting documents

The review comments have helped us improve our manuscript.

Thank you very much

Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors have solved all the raised questions with solvency. I recommend publishing. Congratulations

Author Response

Dear Reviewer

Thank you very much for your valuable comments. 

The review comments have helped us improve our manuscript.

Thank you very much

Authors

Round 3

Reviewer 1 Report

The manuscript “3D Hydrodynamic Modelling Enhances the Design of Tendaho Dam Spillway, Ethiopia” by Demeke et al. has again improved since the last version, but the issues regarding the methodology as well as the coherence of the results, discussion, and conclusions are not resolved at all. In particular, it is still not clear how the structure optimization process was done – there is one bullet point in L146 that mentions optimization, but there are no technical explanations in the Methodology section. Neither the Results, nor the Discussion section comment on, or mention structural optimization. The “Recommendations & Conclusions” section states that optimization was done and that 3D modeling was helpful in this procedure, but these conclusions and recommendations are not supported by the results/discussion sections.

I read the supplemental file and the model is well described there. However, the Authors write in their conclusions about an optimization of the structure based on 3D modelling. There should be some decision tree, followed by a description of procedures about how the structure was actually optimized and how the model results were used to perform this optimization. I can't find any hint on this important part, which in my point of view is the most interesting issue of the manuscript: In which way does modelling constructively aid to improve hydraulic structures? Demeke et al. have used a procedure for this and this procedure should be clearly stated, followed up in the results, and intelligibly summarized in the conclusions.

Authors mention improvements of the language, but there are still many issues to be resolved. I strongly recommend engaging a third party for revising the language.

The Figures are still poorly organized and difficult to understand, not because the technique is complex, but because of the presentation style. Some more comments on the Figures:

-          Remove the 3D representation in Figs. 6-9.

-          Adapt the Color of information points (Figs. 5-9) to the color legends.

-          Verify that “Crust” is the correct term in the figures.

-          Do not put bullet point text in any Figure (these should be part of the text and summarized in figure captions).

-          Fig. 9.3: Where does the water outside of the channel come from? Can such a 3D model be correct?

I hope these new remarks will help to improve the manuscript further.

Author Response

Dear Reviewer 

 Thank you very much for your valuable comments. We have addressed all the comments and responded accordingly below each comment. We have also indicated where in the manuscript the changes are made. We have added supporting document. Also the reply is also attached. The review comments have helped us improve our manuscript. Thank you very much Authors 

Author Response File: Author Response.docx

Round 4

Reviewer 1 Report

BROAD COMMENTS

The manuscript was improved and the new table in the supplemental file is theoretically useful; “theoretically”, because the design improvement procedure is still not described (see specific comments L263 + L321). Moreover, the language remains poor (eye-catching wording/formatting issues: Sillway, Tedaho, AutoCAD/AUTO CAD / Auto CAD, and more).

SPECIFIC COMMENTS

L12: Delete “-” (much more wording, grammar, and formatting issues)

L263: What decision tree leads to this modification?

L321: Old concrete blocks were mobilized by the previous flood; just replacing the blocks, in conclusion, is hardly understandable. Design adjustments are required – how was that addressed in this study and how are these supported by the results? Authors, please note that just changing the conclusions is not sufficient; they need to be supported by the results.

L323/325/328/330: These bullet points transfer basically the same message; thus, merge the four points into 1-2 and simplify.

Figures: Remove bullet points and other issues (see the last review).

Author Response

Dear Reviewer

Thank you very much for your valuable comments. We have addressed all the comments and responded accordingly below each comment. We have also indicated where in the manuscript the changes are made.

The review comments have helped us improves our manuscript.

Please the attachment also.

Thank you very much

Authors

Author Response File: Author Response.docx

Round 5

Reviewer 1 Report

The manuscript “3D Hydrodynamic Modelling Enhances the Design of Tendaho Dam Spillway, Ethiopia” by Demeke et al. has gained coherence since the last version. With the changes made, it is clear that this manuscript corresponds to a project summary. Therefore, the word “enhances” since the design is only verified, not enhanced. In linguistic terms, fundamental improvements are still needed, with external support seemingly necessary. Authors may consider 2D surface or contour plots to increase the intelligibility of their figures.

Some specific remarks:

L363-365: Delete lines, including empty bullet point and last bullet point.

Fig. 3: Add units/explain numbers 0-367.77 (stations?) at the channel side; moreover, the flow direction on this figure indicates that this figure is oriented in the opposite sense as in Fig. 2 and results-figures. Unify figure (channel) orientation.

Fig. 10: Bullet points still in figure. Delete and integrate into text; Replace “Before/After” with “Upstream/Downstream”, respectively and where applies.

Fig. 11: Bullet points still in figure. Delete and integrate into text.

I hope these new remarks will help to improve the manuscript further -- Happy New Year.

Author Response

Dear Reviewer

Thank you very much for your valuable comments. We have addressed all the comments and responded accordingly below each comment. We have also indicated where in the manuscript the changes are made.

The review comments have helped us improves our manuscript.

Thank you very much. Happy New year.

Authors

Comment and reply

1.     . Authors may consider 2D surface or contour plots to increase the intelligibility of their figures.

2D plot with contour has been added

2.     L363-365: Delete lines, including empty bullet point and last bullet point.

Done

3.     Fig. 3: Add units/explain numbers 0-367.77 (stations?) at the channel side; moreover, the flow direction on this figure indicates that this figure is oriented in the opposite sense as in Fig. 2 and results-figures. Unify figure (channel) orientation.

Additional information is added. However, the distance or measurement is from the outlet to the reservoir. Explanation is already given in L 199. The orientation of flow is also correct.

4.     Fig. 10: Bullet points still in figure. Delete and integrate into text; Replace “Before/After” with “Upstream/Downstream”, respectively and where applies.

     Done

5.     Fig. 11: Bullet points still in figure. Delete and integrate into text.

     Done