Comparing Depth-Integrated Models to Compute Overland Flow in Steep-Sloped Watersheds

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The present study examines different depth-integrated model solvers applied to artificial watersheds 24 and compares results produced by different solver types. Overall, the paper is good and focus on interesting topics. However, there are some issues that needs authors attention and clarification. I suggest to return this work as moderate revision to authors: 

1- Almost all the results are too qualitative! Especially, in abstract no clear out can be noted. I propose to make  the comparison various model quantitative.  

2- The quality of fig 1 and 3 are too low and needs improvement. 

3- The conclusions needs improvement. It is not reasonable to to have or refer to a table in conclusions and abstract. 

4- In introduction, the aim of study has not been properly defined. 

Author Response

Additions, changes, and responses to reviewer comments

This revision included a significant number of changes, most notably

1. Replacing the qualitative “rating tables” with quantitative evaluations of error as the final section of the results. Additional comments on the relative merits of the solutions methods are included in the Results sections where appropriate, and summarized in the Conclusion section
2. A section on Hydraulic Depths was added to illustrate the movement of overland flow across the watersheds at critical times. These illustrated the value of 2d modelling but required additional post processing beyond HEC-RAS.
3. More focused introduction with elimination of redundancies. A better structure where results are presented on a consitent basis.
4. Thorough review of grammar, structure, punctuation, etc..using the editing of a native-language writer.
5. Re-drawing figures to make them clearer.

 

Reviewer 1

The present study examines different depth-integrated model solvers applied to artificial watersheds 24 and compares results produced by different solver types. Overall, the paper is good and focus on interesting topics. However, there are some issues that needs authors attention and clarification. I suggest to return this work as moderate revision to authors: 

1- Almost all the results are too qualitative! Especially, in abstract no clear out can be noted. I propose to make  the comparison various model quantitative.  

Answer:We have added a significant amount of quantitative comparison. The outflow hydrographs were compared numerically using KGE, Nash-Sutcliff and Pearson.

 

2- The quality of fig 1 and 3 are too low and needs improvement. 

The figures have been redrawn and should now be clearer.

3- The conclusions needs improvement. It is not reasonable to to have or refer to a table in conclusions and abstract.

We have improved the conclusions.

4- In introduction, the aim of study has not been properly defined. 

We have stated the aim of the study more clealy

Reviewer 2 Report

Comments and Suggestions for Authors

It is well-written but lack of novelty found. 

Figures are not up to the mark. It has been suggested that higher-resolution figures be reinserted. 

Minor formatting issues, such as inconsistent figures and table captions, can detract from the manuscript's overall readability.

This journal needs submissions that push the boundaries of current knowledge and offer new theoretical or methodological contributions.

 

 

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Additions, changes, and responses to reviewer comments

This revision included a significant number of changes, most notably

1. Replacing the qualitative “rating tables” with quantitative evaluations of error as the final section of the results. Additional comments on the relative merits of the solutions methods are included in the Results sections where appropriate, and summarized in the Conclusion section
2. A section on Hydraulic Depths was added to illustrate the movement of overland flow across the watersheds at critical times. These illustrated the value of 2d modelling but required additional post processing beyond HEC-RAS.
3. More focused introduction with elimination of redundancies. A better structure where results are presented on a consitent basis.
4. Thorough review of grammar, structure, punctuation, etc..using the editing of a native-language writer.
5. Re-drawing figures to make them clearer.

Reviewer 2

It is well-written but lack of novelty found.

This is a novel application of a well-tested software package. It was a result of difficulties we have experienced in the field using other Hydrological models, including HEC-HMS. This work is a “between step” to develop a more comprehensive (for steep watersheds) distributed flow modeling approach. The next step involves the incorporation of more specific vegetative cover, soil infiltration, and other features common to hydrological analysis of a watershed.

Figures are not up to the mark. It has been suggested that higher-resolution figures be reinserted. 

We have improved all the figures

Minor formatting issues, such as inconsistent figures and table captions, can detract from the manuscript's overall readability.

Figures, tables, equations and refereces have been cross-checked for consistency..

This journal needs submissions that push the boundaries of current knowledge and offer new theoretical or methodological contributions.

As stated previously we consider this a step toward an improved modeling approach for hydrological conditions that often defy prediction.

 

Reviewer 3 Report

Comments and Suggestions for Authors

This study focuses on analyzing overland flow in steep-sloped watersheds, where high-intensity rainfall triggers flash floods. The investigation compares depth-integrated hydrodynamic model solvers, revealing that Shallow Water Equation solutions are the most stable and consistent, while Diffuse Wave Equation solutions fail under steep slope conditions. Large Eddy Simulation improves modeling accuracy for turbulent flows but complicates Shallow Water solutions. Overall, the paper needs more clarification and work; here are the major comments:

*The introduction section could be improved by clearly stating and explaining the focus of the research, the conceptual and theoretical framework, and the relevant literature review studies that were utilized in conducting this research study.

*How can model complexity and accuracy be balanced for overland flow simulations in steep watersheds?

*What level of mesh refinement is necessary to optimize simulation accuracy without excessive computational demand?

*Which turbulent flow parameters are most influential in predicting accurate overland flow behavior?

*How generalizable are the findings for natural watersheds with variable terrain and hydrological characteristics?

*Conduct Further Validation on natural watersheds to confirm the general applicability of findings beyond artificial models.

*Overall, the discussion and caveats part is weak. The Discussion should summarize the manuscript's main finding(s) in the context of the broader scientific literature and address any study limitations or results that conflict with other published work.

*The conclusion section should summarize your results and outline future work. Please revise accordingly.

*Language editing is recommended.

*Grammar editing is recommended.

Comments on the Quality of English Language

*Language editing is recommended.

*Grammar editing is recommended.

Author Response

Additions, changes, and responses to reviewer comments

This revision included a significant number of changes, most notably

1. Replacing the qualitative “rating tables” with quantitative evaluations of error as the final section of the results. Additional comments on the relative merits of the solutions methods are included in the Results sections where appropriate, and summarized in the Conclusion section
2. A section on Hydraulic Depths was added to illustrate the movement of overland flow across the watersheds at critical times. These illustrated the value of 2d modelling but required additional post processing beyond HEC-RAS.
3. More focused introduction with elimination of redundancies. A better structure where results are presented on a consitent basis.
4. Thorough review of grammar, structure, punctuation, etc..using the editing of a native-language writer.
5. Re-drawing figures to make them clearer.

Reviewer 3

This study focuses on analyzing overland flow in steep-sloped watersheds, where high-intensity rainfall triggers flash floods. The investigation compares depth-integrated hydrodynamic model solvers, revealing that Shallow Water Equation solutions are the most stable and consistent, while Diffuse Wave Equation solutions fail under steep slope conditions. Large Eddy Simulation improves modeling accuracy for turbulent flows but complicates Shallow Water solutions. Overall, the paper needs more clarification and work; here are the major comments:

*The introduction section could be improved by clearly stating and explaining the focus of the research, the conceptual and theoretical framework, and the relevant literature review studies that were utilized in conducting this research study.

We believe we have clarified the introduction and literature reviews

*How can model complexity and accuracy be balanced for overland flow simulations in steep watersheds?

We feel we are demonstrating just that.

*What level of mesh refinement is necessary to optimize simulation accuracy without excessive computational demand?

There is no simple answer to this question, therefore the motivation for this study. As we pointed out in the paper, solution methods provide varying levels of accuracy on a case by case basis. There is no direct, simple extrapolation or trend you can follow.

*Which turbulent flow parameters are most influential in predicting accurate overland flow behavior?

This has been highlighted in the results section

*How generalizable are the findings for natural watersheds with variable terrain and hydrological characteristics?

These are all good questions. We  have been able to give some insight into these questions. As stated earlier, this has been our intial work into adapting this approach. As part of ongoing research we are doing just that.

*Conduct Further Validation on natural watersheds to confirm the general applicability of findings beyond artificial models.

This is obviously a future step in our research.

*Overall, the discussion and caveats part is weak. The Discussion should summarize the manuscript's main finding(s) in the context of the broader scientific literature and address any study limitations or results that conflict with other published work.

We have improved this section

We have addressed much of this. It is a judgement call as to how broad to discuss the context of scientific literature.

*The conclusion section should summarize your results and outline future work. Please revise accordingly.

This has been done

*Language editing is recommended.

*Grammar editing is recommended.

The manuscript has been thoroughly reviewed by a native English speaker/writer.

 

 

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors The paper is in a better shape with all the revision. The authors integrated all reviewers' comments in their paper and presented an improved version. The paper is ready to be published, I have no further comments.