GIS-Based Landslide Susceptibility Mapping of the Circum-Baikal Railway in Russia Using UAV Data

Round 1

Reviewer 1 Report

In recent years, remote sensing technology, especially UAV data acquisition technology, has been widely used in geological hazard assessment. Based on UAV, this study collected the images and DEM of a small area slope, and carried out the landslide susceptibility assessment in this small area. On the whole, the quality of this study is low, and it is still far from being published on RS. The specific problems are as follows: (1) The data in this study have great defects, only UAV data and DEM in a very small area, but the regional method is used to evaluate the landslide susceptibility. Obviously, this method is not scientific and the results obtained are not of great significance; (2) The regional landslide evaluation method adopted in this study, namely AHP method, is a very backward method. This method will be affected by great human factors, and the result will deviate greatly from the actual situation. (3) There are major problems in the technological route of this study, and the results obtained are of little value. Therefore, it is recommended to reject the manuscript.

Author Response

Dear Reviewer,

Thanks for your feedback on the submitted article “GIS-based landslide susceptibility mapping of The Circum-Baikal Railway in Russia using UAV data”.

We agree that further elaborating on innovative methods of geological hazard assessment using UAV data acquisition technology would be of great significance. We will improve our study by adding an explanation on method choice and revise the structure. We would greatly appreciate it if you could recommend any relevant literature that we shall go through for greater understanding, for this and future manuscripts. Thank you for highlighting issues that we took into consideration for improving our study.

Sincerely,

Svetlana Gantimurova, Alexander Parshin and Vladimir Erofeev.

Reviewer 2 Report

The manuscript presents a landslide susceptibility analysis along a small railway in Russia. The analysis is based on morphometric parameters derivable from digital elevation models in a GIS environment. The approach benefits from UAV high-resolution surveys and uses a simple heuristic approach to map susceptibility to landslide occurrence. Even if there is not a particular novelty in the work, the manuscript has some point of interest for Remote Sensing readers and after a major revision could form a good contribution for the journal.

The main problem of the manuscript is related to the lack of structure since most of the text in the methods is more suitable in the introduction whereas some methods are presented in the results section. Another major concern is the validation of the approach. Currently, it is addressed only qualitatively by inviting the reader to observe and compare figures 8 and 9. It would be more useful if the authors could apply a more quantitative approach based on mapped existing landslides. In general, in the methods, more details should be provided to allow fully understand the choice of the parameters for the susceptibility analysis. Also, the English need to be carefully checked.

More detailed comments and suggestions are reported in the attached pdf.

 

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

 

Thank you very much for the review of our manuscript entitled: “GIS-based landslide susceptibility mapping of The Circum-Baikal Railway in Russia using UAV data”.

 

We sincerely appreciate the time and effort you dedicated to providing feedback on our manuscript and are grateful for the insightful comments and valuable improvements to our paper. Appropriated changes have been introduced to the manuscript. Please, find our responses described below in a point-to-point manner.

 

1. The main problem of the manuscript is related to the lack of structure since most of the text in the methods is more suitable in the introduction whereas some methods are presented in the results section.

 

We have enhanced the structure of the paper according to your suggestions. Thus, we have relocated the methodology background to the introduction and reorganised the overall structure. We have introduced the “Materials and methods” section and divided it into three subsections: Study Area, UAV data acquisition, pre-processing, and LS parameters. We have tried to clearly segregate the methods section and the results part.

 

2. Another major concern is the validation of the approach. Currently, it is addressed only qualitatively by inviting the reader to observe and compare figures 8 and 9. It would be more useful if the authors could apply a more quantitative approach based on mapped existing landslides.

 

We have improved figure 9 and specified the landslides that occurred during the study, confirming the forecasting correctness. As for validation, we strongly agree that the quantitative approach would be a more scientific and demonstrative way to assess the results. However, long-term observations are required, no reliable detailed data are available for the study site.  The discussion of this point is provided in the conclusion.

 

3. In general, in the methods, more details should be provided to allow fully understand the choice of the parameters for the susceptibility analysis.

 

The part of the article describing the choice of the parameters was augmented.

 

4. Also, the English need to be carefully checked.

 

The paper has been carefully revised by a professional language editing service to improve grammar and readability.

 

Thank you for the extensive feedback provided in the attached pdf. We have corrected all the marked issues. We have added more detailed information on used terms clarification. All comments on the text are taken into account.

 

Sincerely,

Svetlana Gantimurova, Alexander Parshin and Vladimir Erofeev.

 

Reviewer 3 Report

The authors presented a technical note regarding the creation of landslide susceptibility map using UAV data and an an analytical hierarchy process in a GIS environment. 

I think that the article has a good idea, but needs more technical details since it a technical note and the significant advances of the research should be highlighted. This is my main concern about the specific manuscript. The authors should explain in a better and more detailed way the scientific value of their research and its main assets. 

Other suggestions-recommendations are:

1) Introduction: Please add some international references regarding landslide detection using UAVs or the generation of landslide susceptibility maps using UAVs. 

2) In figures 1, 3, 4(a,b): please add viewing angle

3) Please add details concerning the processing of UAV data through SfM technique (camera calibration values, processing settings, did you use GCPs? what was the GCP accuracy, tie points accuracy etc).

4) In figure 9: lines, which surround the existing landslides, could be integrated in order to improve the visualisation.

Author Response

Dear Reviewer,

 

Thank you very much for the review of our manuscript entitled: “GIS-based landslide susceptibility mapping of The Circum-Baikal Railway in Russia using UAV data”.

 

• I think that the article has a good idea, but needs more technical details since it a technical note and the significant advances of the research should be highlighted. The authors should explain in a better and more detailed way the scientific value of their research and its main assets

Thank you for your suggestion, corresponding revisions has been done in the revised version. We have added more technical details and background as well tried to better explain scientific novelty of our research.

• Introduction: Please add some international references regarding landslide detection using UAVs or the generation of landslide susceptibility maps using UAVs.

According to your recommendations, we have made extra research regarding landslide detection using UAVs and included more references to the introduction. There are studies about mapping, monitoring and analysis of active landslides.  However, we haven’t found any relevant publications about using UAV-based RS for landslide susceptibility in terms of prediction. If you could recommend some relevant studies, we greatly appreciate it.

• In figures 1, 3, 4(a,b): please add viewing angle

We have added landmarks to understand the location of the site in space.

• Please add details concerning the processing of UAV data through SfM technique (camera calibration values, processing settings, did you use GCPs? what was the GCP accuracy, tie points accuracy etc).

We have added details and expanded the description of the processing of UAV data

• In figure 9: lines, which surround the existing landslides, could be integrated in order to improve the visualisation.

Figure 9 has been improved according to your recommendations

Thank you very much for your crucial comments for our manuscript. We have made a thorough revision based on all of your comments. We hope the revised version can meet the requirement of “Remote Sensing”.

Reviewer 4 Report

This is a valuable study about an interesting topic, but I think major revisions are necessary before the paper is suitable for publication. I have listed specific comments below. I also encourage the authors to carefully edit the grammar throughout the paper.

Abstract:

Page 1, Line 11-12: The phrase "by using remote sensing data as satellite-borne as obtained from unmanned aerial vehicle (UAV)" does not make sense. Please revise for clarity.

Page 1, Line 15-16: Please consider changing the phrase "the first phase of THE long-term study" to "the first phase of A long-term study".

 

Introduction:

Page 1, Line 45: Please consider changing "large-scale mapping" to "fine-scale mapping" or "highly detailed mapping." The use of "large-scale" may cause confusion with some readers, as it could also mean "mapping across a large study area."

Page 2, Line 56: For the same logic listed above, please consider changing "smaller scales" to "coarser scales."

Page 2, Line 61: Please change "Using of" to just "Using."

Page 2, Line 68-69: The sentence that begins "Spatial likelihood" and ends with "triggering factors" is not a complete sentence and does not make sense. Please revise for clarity.

 

Study Area:

Page 2, Line 93: What does "starting populated locality" mean?

Page 3, Line 95: In the caption for Figure 1, please describe what we are looking at in the purple image.

 

Data Acquisition and Preprocessing

Page 3, Line 101: Please change "purpose" to "intend" or "propose."

 

Methodology of Data Processing:

Page 6, Line 170-171: The sentence that begins with "Authors" and ends with "results" does not make sense. Please revise for clarity.

Page 6, Line 173: Please change "a data" to just "data".

Page 8, Line 224-227: Did the authors classify landcover using a NDVI image generated from their UAV imagery? If so, please describe the classification method used.

 

Results and Discussion:

Page 11, Line 277: The authors mention that they verified their results by comparing to images of recent landslides. Did the authors conduct a systematic accuracy assessment of the results?

Page 12, Line 285: I think that Figure 9 can and should be improved. Please provide more context for where these images are located within the study area. Also, I think the authors should consider overlaying the images with the susceptibility map to show whether or not these known landslides were located in the high susceptibility areas.

Conclusions:

Page 12, Line 291: I don't think it is accurate to refer to this methodology as "costless." It requires a UAV, access to GIS and computing power, etc. I think it would be more appropirate to describe this method as "cost-effective" or "lower cost" relative to field survey methods.

 

Author Response

Dear Reviewer,

We greatly appreciate the thorough and thoughtful comments provided on our submitted article “GIS-based landslide susceptibility mapping of The Circum-Baikal Railway in Russia using UAV data”.

Here is a point-by-point response to the comments and concerns.

• Page 1, Line 11-12: The phrase "by using remote sensing data as satellite-borne as obtained from unmanned aerial vehicle (UAV)" does not make sense. Please revise for clarity.

 

Thank you so much for your suggestion. Yes, we have restructured the sentence for better understanding. Hopefully you will find it logical.

 

• Page 1, Line 15-16: Please consider changing the phrase "the first phase of THE long-term study" to "the first phase of A long-term study".

 

Corrected

 

• Page 1, Line 45: Please consider changing "large-scale mapping" to "fine-scale mapping" or "highly detailed mapping." The use of "large-scale" may cause confusion with some readers, as it could also mean "mapping across a large study area."

 

Corrected

 

• Page 2, Line 56: For the same logic listed above, please consider changing "smaller scales" to "coarser scales."

 

Corrected

 

• Page 2, Line 61: Please change "Using of" to just "Using."

 

Corrected

 

• Page 2, Line 68-69: The sentence that begins "Spatial likelihood" and ends with "triggering factors" is not a complete sentence and does not make sense. Please revise for clarity. 

 

Revised

 

• Page 2, Line 93: What does "starting populated locality" mean?

 

Changed to “settlement”

 

• Page 3, Line 95: In the caption for Figure 1, please describe what we are looking at in the purple image.

 

Revised

 

• Page 3, Line 101: Please change "purpose" to "intend" or "propose."

 

Corrected

 

• Page 6, Line 170-171: The sentence that begins with "Authors" and ends with "results" does not make sense. Please revise for clarity.

 

Corrected

 

• Page 6, Line 173: Please change "a data" to just "data".

Corrected

• Page 8, Line 224-227: Did the authors classify landcover using a NDVI image generated from their UAV imagery? If so, please describe the classification method used.

We have added some information regarding land-cover classification technique, based on NDVI generated from our UAV data.

 

• Page 11, Line 277: The authors mention that they verified their results by comparing to images of recent landslides. Did the authors conduct a systematic accuracy assessment of the results? Page 12, Line 285: I think that Figure 9 can and should be improved. Please provide more context for where these images are located within the study area. Also, I think the authors should consider overlaying the images with the susceptibility map to show whether or not these known landslides were located in the high susceptibility areas.

Thank you for your comments. We have improved the figure and pointed out the landslides that occurred during the study, confirming the prognostic constructions' correctness. For a quantitative assessment, the results of long-term observations are required, data are not available. A discussion of this point is provided in the conclusion of the paper.

 

• Page 12, Line 291: I don't think it is accurate to refer to this methodology as "costless." It requires a UAV, access to GIS and computing power, etc. I think it would be more appropriate to describe this method as "cost-effective" or "lower cost" relative to field survey methods.

 

Revised

• I also encourage the authors to carefully edit the grammar throughout the paper.

The paper has been carefully revised by a professional language editing service to improve grammar and readability.

 

We sincerely appreciate the valuable comments and suggestions from the reviewers. The

thorough review helped immensely in the shaping of the manuscript. The suggestions and

comments have been closely followed and revisions have been made accordingly.

 

Best Regards, Svetlana Gantimurova, Alexander Parshin and Vladimir Erofeev.

Round 2

Reviewer 1 Report

There are some major problems in the foundation of the manuscript, and the related contents have little scientific research value and significance. Although the authors have made some modifications to the manuscript, it has not changed the essence of the manuscript, so it is suggested to reject the manuscript.

Author Response

nothing to discuss

Reviewer 2 Report

The authors addressed most of the issues I raised in my previous round of revision. They did not provide a quantitative analysis to validate their approach but they correctly stressed the importance to undertake such analysis in future research when they will have more data. I think that for a technical note this is sufficient. In general, the manuscript quality is increased and it is quite ready for publication. 

I suggest using the term DEM (Digital Elevation Model) for digital models derived from UAV or satellite imagery because they cannot reproduce bare earth surface as Digital Terrain Models (DTM) derived from LiDAR data. In my opinion, is preferable to use DEM in place of DTM throughout all the manuscript.

Author Response

Authors are very grateful to the Reviewer for the precise comments that made it possible to make the correct accents in the article.

In relation to the terms DSM, DTM, DEM, clarifications have been made in the article.

 

Reviewer 3 Report

Thank you for your revisions.

The article is starting to make more sense to me.

I would like to change a few more things:

"1.Introduction", line 44, line 52: please define ERS. What ERS stand for?

"3.3. LS parameters", line 369: change figure 7a into figure 8a

"3.3. LS parameters", line 396: change figure 7e into figure 8e

"4. Results", line 431: change figure 9 into figure 10

Author Response

Authors are grateful to the distinguished Reviewer for working on our article. All noted shortcomings have been eliminated.

Reviewer 4 Report

The authors have done an excellent job of addressing my major concerns about the methods, substance, etc of the paper. However, I still have lingering concerns about the amount of grammatical errors in the paper. Please carefully revise the paper for proper grammar one more time. After this minor grammatical revision, the paper should be suitable for publication.

Author Response

We very thank the reviewer for his work, thanks to this, the article has been significantly improved.

Authors asked a native speaker to read the article, but in the current version of the text, he did not notice any significant problems.