Instability of Embankment Slopes Due to Overflow and Drawdown

Round 1

Reviewer 1 Report

This manuscript presented an interesting study on the stability analysis for levee overflow failure due to water level fluctuation. In general, the manuscript is well-organized and revision is suggested. Some technical issues can be addressed or clarified to improve the quality of the manuscript:

(1)  Lines 103-104: ‘Table 2 presents the multivariate probability distribution equations of commonly known copula functions’. Until recently, several copula functions have been developed, such as the Gaussian copula, t copula, and Vine copula. In practical applications, how to select an appropriate copula function when using the proposed approach.

(2)  Lines 108-109: ‘Figure 2 shows the results of modeling water levels based on observed antecedent rainfall and water level data using the Copula function’. Please specify which Copula function was used herein. Furthermore, What’s the impact of Copula function selection on the initial water level modeling and embankment slope stability analysis.

(3)  Lines 123-125: ‘The risk assessment of dams commonly used in South Korea assumes that the initial water level is set as either the designed flood water level or the seasonal flood limit water level. This assumption neglects the consideration of water levels caused by antecedent rainfall’. Whether the approaches developed in previous studies are unable to consider the case of antecedent rainfall. Please simply summarize the differences between them.

(4)  Lines 140-141: ‘The red line in Figure 4 represents the dam crest, and the simulation was performed 10,000 times’. Please provide more details on how to determine the simulation times in this study.

(5)  Figure 5 presents the results of the analysis, assuming the initial water levels derived from antecedent rainfall using the Copula function. Please specify which Copula function was used herein.

(6)  Table 5 lists the physical and hydraulic parameters of the soil materials used in this study. Although the SWCC parameters were presented, the SWCC model applied in this study is unclear, please specify it in the main text.

(7)  Lines 200-203: ‘The results indicate that the upstream slope exhibits a relatively low risk at the initial 90% water level due to the existence of the water pressure acting on the slope surface. However, when the water pressure on the slope surface is absent under drawdown conditions, the slope presents a high risk of instability’. Please explain the potential reasons underlying this observation.

(8)  Figures 8, 10, 12, 15, and 17 plotted the stability of the embankment under different scenarios. It is well-recognized that several limit equilibrium methods have been embedded in the Geostudio software (e.g., Bishop and Morgenstern-Price method). Please specify which LEM method was used in this study.

(9)  As reported in the introduction, ‘various hydraulic and hydrological variables contributing to the embankment collapse are being determined and incorporated into the risk analysis’. Some latest research may provide a better understanding for readers, such as ‘Point estimation method: Validation, efficiency improvement, and application to embankment slope stability reliability analysis’, ‘Probabilistic stability analysis of earth dam slope under transient seepage using multivariate adaptive regression splines’ and ‘Kriging based reliability and sensitivity analysis – Application to the stability of an earth dam’.

Minor editing of English language required.

Author Response

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Reviewer 2 Report

This paper is an interesting and necessary topic as it analyzes the effect on the stability of levee according to the change in water level. Numerical analysis was also applied and analyzed appropriately to achieve the research goal.

However, since research on recent research trends is considered insufficient, it is recommended to add recent literature studies. Also, please modify the citation method according to the format of the publisher of MDPI.

If the minor content is appropriately addressed in revision, it is considered suitable for publication.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

I read the manuscript titled "Stability analysis for levee overflow failure due to water level fluctuation". The comments are as follows, which the dear authors should response them. In my opinion, the manuscript needs minor revision.

1- Several formatting errors were observed throughout the text.

2- Improve abstract part. The abstract should contain Objectives, Methods/Analysis, Findings, and Novelty /Improvement.

3- At the end of the introduction, introduce the novelty of your study and mention the organization of your paper.

4- Could the authors provide better quality of Figures 4 and 5?

5- The conclusion needs revision.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The manuscript has been revised according to the comments.

 Minor editing of English language required.