Modeling and Risk Analysis of Dam-Break Flooding in a Semi-Arid Montane Watershed: A Case Study of the Yabous Dam, Northeastern Algeria

Round 1

Reviewer 1 Report

Dear authors.

Thank you for the provided responses that addressed my comments. 

Author Response

We want to express our sincere gratitude to Reviewer #1 for the time dedicated to the review and the comprehensive, profound, and constructive remarks, which allowed us to improve the quality of our manuscript. Please see the attachment.

Author Response File: Author Response.doc

Reviewer 2 Report

Review of: "Modeling and Risk Analysis of Dam-Break Flooding in a Semi‐Arid Montane Watershed: Case study of Yabous Dam, Northeastern Algeria" by Gaagai et al.

The authors use a HEC-RAS hydraulic model in five sites selected downstream the embankment dam. The paper covers various interesting topics, including dam-break flooding, risk analysis , and flood hazards. In addition, they provided useful insights into the uncertainty for the input parameters selection, for any dam design and dam feature of future works.

I have various minor comments that should be addressed.

• Line 128: Add benefits of “HEC-RAS" model and also most important limitation of other models.
• Line 132-135: Show aims of study in more clear way. For example: This study aimed to evaluate: 1)..., 2),...3).
• Section 2.1.1: add information about evapotranspiration and air temperature of study area. 
• Try to improve the quality of figure 4. 
• Line 273: In total, 122 cross-sections were implemented. Randomly?
• Line 489-499: Move this part in a section about the statistical analysis.
• It would be helpful to show some implication of your study (according to your results) for water resources management, at the end of conclusions.

 

Author Response

We want to express our sincere gratitude to Reviewer #2 for the time dedicated to the review and the comprehensive, profound, and constructive remarks, which allowed us to improve the quality of our manuscript. Please see the attachement.

Author Response File: Author Response.doc

Round 2

Reviewer 2 Report

Great job! 

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 paper presents a well-documented case study, with detailed description of literature, study site, method, parameter analysis and discussions. It is certainly a large amount of work that lies behind the paper. 

However, besides the very well documentation of the project, I do no find anything new or useful to the reader and it writes merely a state of the practice. Parameter analysis showing breach time is dominant is nothing new either (similar results published 20 years ago). Any publication of a study should provide some useful aspects to the reader. 

Reviewer 2 Report

Dear Editor.

I have finished my review on the proposed paper “Modeling and Risk Analysis of Dam-Break Flooding in a Semi‐Arid Montane Watershed.” water-1548126-peer-review-v1.

 

Summary of the manuscript:

In the proposed paper, the authors’ goal is to simulate dam-breach failure scenario of Yabous dam (NE Algeria) and analyze its influence on areas (urban and natural environments) downstream the dam. They applied the one-dimensional HEC-RAS hydraulic model and sensitivity analysis and the results showed that an emergency alarm is mandatory in area with reservoirs.

 

General review:

1. Generally, the manuscript presents a very interesting topic and the specific research seems to include some significant points for the research community of this field.
2. The proposed paper is very well written with very good use of English language. Except some minor grammatical mistakes and word errors, this paper is written with a very good scientific style. The authors should check again the paper to correct these minor mistakes.
3. The proposed paper is very well structured. It begins with an analytical Introduction with the appropriate references that helps the reader to get into the subject immediately. In Introduction there is an effort to provide previous studies with similar scientific content, which took place in the research area and in some cases in other countries. Authors describe and set very well the scientific problem and how other researchers have approached. At the end of Introduction, authors clearly state the goals of the research.
4. The methodology is generally very interesting, and well explained, so other researchers could easily repeat it. Every aspect of methodology is well documented with the use of the appropriate literature.
5. The results scientifically explained with the use of the appropriate scientific literature.
6. The quality of the work in Discussion section is very high and qualitative.
7. Conclusions are appropriate for this paper.

 

Points for revision:

In my opinion, the proposed paper could be characterized as a high-quality research work, complies with aims of Water. 

Nevertheless, I have some minor points for revision.

Lines 187-202: Here you use 2 decimal digits, but they are both zero. Remove the two decimals.

Figure 6: Here you depict the cross sections. Also, we can see that two bridges are built perpendicular to stream. However, very few (almost nothing) information we know about these lateral structures. Did you follow the standard procedure of HEC-RAS to simulate the flood discharge from these structures? Or you simply ignore them taking into account only the DEM morphology. You should add some information about these bridges. And eventually, these bridges will be destroyed in an event of dam failure?

Line 299: “….flood hydrograms….”. Maybe you mean hydrographs? You should check again the text for minor mistakes.

2.3. Estimation of Dam-Breach Parameters: You should add in your paper the equation that you use for the calculation of the sediment load that was produced by the dam eroded construction materials and by the stream erosion.

Table1 and in all the text: The discharges are huge. For that reason, two decimal digits are not necessary. Keep one decimal.

Figure 14: I searched the study area in google earth. However, I can’t understand how much residential area is under flood risk. Most of the city is out of the flood passage. You can add some polygons in figure 14 to highlight the urban areas that are in high risk.

Lines 584-586: Here you say again about the flood event during the construction of the dam. In most countries the flood design for dams is the 1000 years return period and for other works the 500 years or 100 years. For various reasons, dams (and other works) failed to discharge the flood discharge with devastating results. One common problem is the known uncertainties of the hydrological models (to calculate the hydrographs), and a second is that many times the storm event exceeded the 1000 (or 500, 100…) years return period. For those reasons, some researchers propose to increase the calculated maximum discharge (for the selected return period) by 20%, as a security option (Kastridis et al. 2021, Andreadakis et al. 2020). I think that you should add a small paragraph highlighting the above mentioned, adding the proposed literature.

 

Andreadakis, E.; Diakakis, M.; Vassilakis, E.; Deligiannakis, G.; Antoniadis, A.; Andriopoulos, P.; Spyrou, N.I.; Nikolopoulos, E.I. Unmanned Aerial Systems-Aided Post-Flood Peak Discharge Estimation in Ephemeral Streams. Remote Sens. 2020, 12, 4183.

Kastridis, A.; Theodosiou, G.; Fotiadis, G. Investigation of Flood Management and Mitigation Measures in Ungauged NATURA Protected Watersheds. Hydrology 2021, 8, 170. https://doi.org/10.3390/hydrology8040170.