The Variation in Boulder Bars Triggered by the 2018 Sedongpu Natural Dam Failure in the Yarlung Tsangpo River

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript studied the geomorphological changes in a river reach located 173 km downstream of the Sedongpu natural dam on the Yarlung Tsangpo River to quantitatively evaluate the impact of outburst floods on the topographical and landform variations in downstream channels. The manuscript has clear logic and substantial content, but there are still some problems that need further discussion and revision. The specific recommendations are listed as follows:

 

1. Formatting errors. Variables in the manuscript should be italicized, while numbers should not be, such as Eq. (3), Eq. (6) and so on. There should be a space between numbers and units. The labeling in Figure 2 is unclear.

 

2. The expression in Lines 207-209 is confusing. What dose “the numbers of boulder bars with perimeters greater than P and P” mean?

 

3. The two subgraphs in Figure 5 can be combined into one image, which will be more conducive to analysis.

 

4. In Section 3.5, the conclusion of “the numbers of boulder bars per 17.3 km of river length increase first and then decrease with increasing distances from the dam” is not rigorous, as well as the conclusion of “the farther away from the dam, the weaker the impact of floods on the number”.

 

5. More relevant references can improve the introduction section, such as the articles titled “The geomorphic impact of outburst floods: Integrating observations and numerical simulations of the 2000 Yigong flood, eastern Himalaya”, “Experimental investigations on the spillway section shape of the breaching process of landslide dams” and so on.

Author Response

Comments 1: Formatting errors. Variables in the manuscript should be italicized, while numbers should not be, such as Eq. (3), Eq. (6) and so on. There should be a space between numbers and units. The labeling in Figure 2 is unclear.

Response 1: Thank you for your valuable feedback. I have checked the format of the full text according to your comments and corrected the errors. This includes the issue of variables being italicized, numbers not being italicized, and there should be Spaces between numbers and units. The markup page in Figure 2 has been modified in response to your comments, enlarging the markup that is not clear in Figure 2.

 

Comments 2: The expression in Lines 207-209 is confusing. What dose “the numbers of boulder bars with perimeters greater than P and P” mean?

Response 2: The authors have revised the sentence. Please see Lines 240-242.

 

Comments 3: The two subgraphs in Figure 5 can be combined into one image, which will be more conducive to analysis.

Response 3: Thank you for the valuable feedback from the reviewer. I have merged the two subgraphs in Figure 5 according to your comments.

 

Comments 4: In Section 3.5, the conclusion of “the numbers of boulder bars per 17.3 km of river length increase first and then decrease with increasing distances from the dam” is not rigorous, as well as the conclusion of “the farther away from the dam, the weaker the impact of floods on the number”.

Response 4: Thank you for your valuable opinion. I have deleted the imprecise conclusion in Section 3.5 that you mentioned.

 

Comments 5: More relevant references can improve the introduction section, such as the articles titled “The geomorphic impact of outburst floods: Integrating observations and numerical simulations of the 2000 Yigong flood, eastern Himalaya”, “Experimental investigations on the spillway section shape of the breaching process of landslide dams” and so on.

Response 5: Thanks a lot for the editor's valuable suggestion, which is helpful to

revise and improve our paper. I have added relevant references according to your comments. And improved the introduction part. For details, please see lines 36-37 in the introduction part.

Reviewer 2 Report

Comments and Suggestions for Authors

This subject is very long, and it would be preferable to use a shorter topic.

Abstarct is not well-written. This is a similar introduction. The attention should be mainly on the results.

What is the manuscript's novelty? Please include some sentences in the last paragraph of the introduction.

Line 91: What is LT?

Please add the study area's neighbours in A section of Figure 1.

Line 126. Equation 5. There are several errors in the equation. Revise it.

Please provide more information regarding the graphs and plots within Figure 2.

Line 287. What image? Please provide more information regarding the satellite images.

Please include some geomorphological parameters in your results. This manuscript requires further explanation of the geology and dam condition. 

Comments on the Quality of English Language

Extensive english editing required.

Author Response

Comments 1: This subject is very long, and it would be preferable to use a shorter topic.

Response 1: Thank you for the reviewer's comments. I have changed the title to “The variation of boulder bars triggered by the 2018 Sedongpu natural dam failure in the Yarlung Tsangpo River”.

 

Comments 2: Abstarct is not well-written. This is a similar introduction. The attention should be mainly on the results.

Response 2: Thanks a lot for the suggestion. We have modified the abstract according to your comments. Please refer to the abstract section for details.

 

Comments 3: What is the manuscript's novelty? Please include some sentences in the last paragraph of the introduction.

Response 3: Thanks very much for the reviewer’s comment. We have revised the Introduction section according to your comments and pointed out the novelty of the manuscript. Please see lines 103-106 for details.

 

Comments 4: Line 91: What is LT?

Response 4: Thank you for the reviewer’s question. L_T is the distance from the natural dam. We have fixed this issue at line 200.

 

Comments 5: Please add the study area's neighbours in A section of Figure 1.

Response 5: Thank you very much for the reviewer's feedback. We have modified Figure 1 according to your comments.

 

Comments 6: Line 126. Equation 5. There are several errors in the equation. Revise it.

Response 6: Thank you for the reviewer's comments. We have modified Equation 5 according to your comments.

 

Comments 7: Please provide more information regarding the graphs and plots within Figure 2.

Response 7: Thank you very much for the valuable feedback from the reviewer. We have revised Figure 2 according to your comments and added more detailed information in the figure.

 

Comments 8: Line 287. What image? Please provide more information regarding the satellite images.

Response 8: Thank you for the valuable feedback from the reviewer. We have added more detailed information of satellite images in line 315-316.

 

Comments 9: Please include some geomorphological parameters in your results. This manuscript requires further explanation of the geology and dam condition.

Response 9: Thanks a lot for the reviewer’s valuable suggestion, which is helpful to revise and improve our paper. We added some relevant parameters to the results section. For example, the range of length, width and flattening of the gravel bar of the river. Please see lines 159-168 for details.

Reviewer 3 Report

Comments and Suggestions for Authors

The paper analyses the effects on the geometry and distribution of the boulder bars induced by the flood following the collapse of a natural dam (landslide dam).

The methodology used is rigorous and based on the definition of original and effective morphological indices regarding the results obtained, which are convincing.

I have only one suggestion: I think it is interesting to add a brief description of the event that produced the landslide dam - in particular the type of landslide that caused the barrier and above all the type of material that constituted the collapsed barrier - highlighting the influence that this collapsed material may have had in the distribution and variation of geometry of the boulders bars.

A few very modest typos are indicated in the attached PDF file.

Comments for author File: Comments.pdf

Author Response

Comments 1: I think it is interesting to add a brief description of the event that produced the landslide dam - in particular the type of landslide that caused the barrier and above all the type of material that constituted the collapsed barrier - highlighting the influence that this collapsed material may have had in the distribution and variation of geometry of the boulder bars.

Response 1: Thanks for your suggestion. The authors have added related contents about the landslide dam events in Paragraph 3 of Page 2 as your suggestion.

 

Comments 2: A few very modest typos are indicated in the attached PDF file.

Response 2: Thanks a lot for your suggestion. We have made modifications to the issue you mentioned in the attached PDF.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I think the manuscript can be accepted as it is.