Debris Flow and Rockslide Analysis with Advanced Photogrammetry Techniques Based on High-Resolution RPAS Data. Ponte Formazza Case Study (NW Alps)

Round 1

Reviewer 1 Report

You have done an impressive piece of work using UAV, which must be the way forward in many applications. However, I found your paper very difficult to read. I am afraid I often became 'lost' in the technical detail, much of which I would suggest is either condensed down or is summarised in supplementary material. 

Comments for author File: Comments.pdf

Author Response

We would thank you for your careful revision that helped us to improve the manuscript. 

In the attached file you can find detailed replies point-by-point. 

As you suggested we also summarized in the supplementary materials some technical results about the accuracy analysis providing improved figures of residual analysis. 

Author Response File: Author Response.docx

Reviewer 2 Report

1.in line 31, what is the RPASS. I think it might be PPAS. The similar question appears in line 80,142. Please ensure it consistently.
2.I think the numbers of keywords is too much. You may reduce it to five or six maximum.
3. in Line 61, you might omit the full comma.
4. In line 114, please use a Capital letter when you mentioned the month or year.
5.In table 1, If you can label the location of the meteorological station in the study area map(Figure.2), it would be better.
6.in line 342, dived might be divided
7.line 535,536,546 what is the meaning of di? 
8.In line 532, how you can remove vegetation, manually or automatically? 
9. I think the conclusion is too much. You might concise it and tell the main contributions.
10. In line 480, all the residues represent to northeast direction. Why? Because of the topography variation caused by failure or other?
11. Please notice your format, considering there are two many separated paragraphs in the current manuscript.
Two following questions are just for discussion rather than a suggestion.
1. In terms of the different selecting strategies in Case 3, why don’t you choose 9 (70% of total 13 points) as GCPs, the rest 4 (30%) as CKP?
2. In my experience, if we input all points as GCPs, the derived accuracy is not very high, as we expected. This is more related to the survey topography and distribution of GCP. What do you think? Of course, I agree with your conclusion. Few GCPS , at least 3 points, can improve the accuracy. Just asking, it is not a suggestion. 

Author Response

Dear Reviewer 2, 

We would thank you for your helpful and careful revision.

We provided to reduce the conclusion and to simplify section 3.4.1 as suggested by the revisor 1. We also summarized in supplementary materials the results of accuracy analysis with improved figures that show planar and vertical residuals.

In the attached file you can find the replies point-by-point 

Best Regards

The authors 

 

 

Author Response File: Author Response.docx

Reviewer 3 Report

Dear authors,

I found your paper very interesting, with sound scientific value. The illustrations are of high quality, the presentation and the analysis of the topic was very well documented. I propose the publication of this article in its present form.

Author Response

Thank you very much for your revision. 

We also provided to improve the manuscript according to the comments of others reviewers.

The Authors  

Reviewer 4 Report

The case history is interesting and involves remote sensing over multiple time periods involving different geomorphic processes all within a relatively confined area.

There are many examples where the wrong English word is used (e.g., filed vs field) such that a spell checker may not find the errors.  English editing would improve the paper and ease of understanding for a reader.  Use of a grammar checker is also recommended (e.g., Grammarly).

There are spelling errors on some figures, e.g., Fig. 2 and 6 legends.

As but a few examples, errors occur on the following lines:

72, 100, 114, 130, 178, 342, 380, 535-6, 706, 727

The fieldwork was not conducted with a primary objective to quantify the accuracy and precision of DSMs or for camera calibrations. It was conducted to determine various changes as a result of rockslides and debris flows.  Therefore, the work is missing some experimental control that would be used if the prime purpose was to assess accuracy and precision.  Nevertheless, the paper describes a reasonable workflow to obtain sufficiently accurate DSMs when using RPAS for this type of field investigation.  RPASs have become a very important tool for field investigations in dangerous terrain and readers can benefit from this paper to ensure they obtain the best possible results when a RPAS is used.

Author Response

We would thank you for your helpful and careful revision. We provided a careful reading of the manuscript also using Grammarly to check typos and English mistake.  We also provided to reduce the conclusion and to simplify section 3.4.1 as suggested by Review 1 by adding supplementary materials. We hope that manuscript is now well improved.

In the attached file you can find detailed replies. A manuscript track change wal also made. 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Hello, thank you for including modifications based on my comments on the submitted version. I have marked up a pdf with some suggestions which I attach. There are still some clarifications needed on one or two of the figures. It would significantly improve the paper if your use of the English language could be better, but I can follow it, and I assume that is what matters most.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 1,

Thank you very much for revising again the manuscript and for appreciating our efforts to  improve it 

You can find in the attached files the detailed replies to the comments

Author Response File: Author Response.docx