Quantifying Transgressive Coastal Changes Using UAVs: Dune Migration, Overwash Recovery, and Barrier Flooding Assessment and Interferences with Human and Natural Assets

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Editor and Authors, the paper shows the analysis of drone images for three different purposes, realted to coastal dynamics. There are several parts that are lacking: Introdcution must be improved, especially stating clearly the objectives. References must be definetely updated. Conclusions are missing. Overall it can become a nice work, but the paper needs more work.  

PS In my opinion, black background fro figures is too "heavy", I suggest to convert to whyte

31-36 references are missing

41-44 I suggest to re-phrase. Lidar is not a "common" method for monitoring changes, because sensors and "platform" to mount it are very expensive. In this regard, it is not just the post-processing being expensive, but also the whole system

44-50 can be much improved, both in terms of number of references and explanation of different drones applications in coastal areas. [8-11] are relevant, but dated. There are plenty of publications with different objectives published in the last 3-4 years. I understand that this is an old work with data from 2015, but literature must be revised and updated to nowadays

51-53 please, state clearly and pointly the objectives of the paper. The senteces are too generalized.  It is important to give a clear and detailed explanation of the purpose of the paper. The objective paragraph must also be closed with a statement about the the scientific/practical value of the work.

Fig.1 for global audience, please insert world location. Caption "The three study cases analyzed in this paper:"...it is enough to give the title "Study sites locations". Caption must also specify what the red boxes indicate

section 3. Please, start giving a general overview and intro, describing that drone flights were performed and specify the purpose of the flight at each study site- Technical details can be described after that intro 

179 "The first survey, conducted from November 19 to 24, 2014.." it is weird to read about 5 days for the pre-winter conditions, and just one day for the post-winter. I suggest to simplify. Perhaps," surveys were performed in middle Nov and middle May, dates corresponding to the start of winter and middle spring season, respectiveley"....something like this

182-183 "Each flight was processed as indicated above" no need of these sentences

185  in scientific papers, avoid being vague. "to highlight sand displacement", better "estimate"....Instead of "some profiles", specify the number. I would rather see the area in square meters, it is not very common to report ha in coastal/beach field

Table 1 caption must be detailed. All acronyms must be specified to help the reader (e.g., NT4). Better specify also "Image acquistion Overlaps" and" Image acquisition sidelaps"

178-233 is it necessary to report in the text all singular dates? the reading is quite tedious, and dates are in Table. Perhaps, the text can instead describe the frwquency, for instance "Three UAV surveys were conducted in the Martignano barrier island between 2016 and  2021 (table1), to determine the evolution of a washover which was likely caused by the impact of two severe storms in 2012 and Feb 2013 [64]". ecc.

Section 4. IVerbs must be with past tense

"it reaches from approximately 1.5 m above m.s.l. near the shore to almost 113 m near the southernmost portion of the dune." revise English. mAybe you meant "it rised"

5. Discussion. From my point of view, keeping highlighting the drone potentiality is not necessary, or at least, can be said just once in the text. In Discussion, it is missing also the limitation and potential lacks of the study, along with a fair evaluation of the surveys. Was the monitoring frequency sufficient, or more surveys would have given better info? ecc

5.4 must be Conclusions, which are missing. Conclusions cannot be a resume of the methodology.It must resume the scientific achievements and understanding. In other words, Conclusions is what you understood from dorne images. 

 

Author Response

Dear Reviewer 1,

 

We are grateful for spending your time on reviewing our manuscript “Quantifying transgressive coastal changes using UAVs: dune migration, overwash recovery and barrier flooding assessment and interferences with human and natural assets”. The revised version of the paper has been changed according to your comments and the suggestions provided by the other Reviewer. We re-wrote almost entirely some parts of the work. It is our belief that the manuscript is substantially improved after making the suggested edits.

In synthesis, the most substantial changes are in the paragraphs:

Introduction: We updated the contextualisation with a new structure of this part and by referencing new and more recent references in order to properly outline the scientific framework of our investigation. The aims of the article have been re-written for a more correct focus on the real content of our work.

Results: We increased the clarity of the findings explanation, especially in the sections 4.2 Martignano.

Discussion / Conclusion: As requested we insert two separate section. The Discussion section includes three sub sections, one for each site. It is dealing with the most important coastal changes and process involving each case study and explored thanks to the UAV surveys. We paid attention to a brief discussion for each case study on the limit of our survey and monitoring and to an improvement hypothesis. The Conclusion section is focusing on the meaning of the results of our surveys in the three case studies and getting a wider context to our results.

 

We have transcribed all your comments in this text, with a point by point response, as reported below.

 

We appreciate your time and look forward to your response.

 

Best regards,

 

      Giulia Casagrande

on behalf of all authors

 

• PS In my opinion, black background for figures is too "heavy", I suggest to convert to white

Answer: We understand the suggestion, but we disagree with it. Our intention was to "do something different" in order to bring out the clear images of the sandy surfaces. Clearly, this is an aesthetic judgment, which is entirely subjective. However, if the editor believes that the background should be changed because it is too heavy, we will make the necessary changes.

• 31-36 references are missing
• 41-44 I suggest to re-phrase. Lidar is not a "common" method for monitoring changes, because sensors and "platform" to mount it are very expensive. In this regard, it is not just the post-processing being expensive, but also the whole system
• 44-50 can be much improved, both in terms of number of references and explanation of different drones applications in coastal areas. [8-11] are relevant, but dated. There are plenty of publications with different objectives published in the last 3-4 years. I understand that this is an old work with data from 2015, but literature must be revised and updated to nowadays
• 51-53 please, state clearly and pointly the objectives of the paper. The senteces are too generalized. It is important to give a clear and detailed explanation of the purpose of the paper. The objective paragraph must also be closed with a statement about the scientific/practical value of the work.

Answer from 2 to 5: As recommended in points from 2 to 5, we have significantly changed the introductory section, giving more attention to recent papers regarding UAV applications in coastal environments and citing a series of review works. We also attempted, as asked in point 5, to be more detailed and emphasise the objectives of the work in all of its parts.

• 1 for global audience, please insert world location. We have added more information to the map (Italy and the Mediterranean Sea), which, along with the coordinates along the edge of the study sites, allows you to correctly identify places in the World. Caption "The three study cases analyzed in this paper:"...it is enough to give the title "Study sites locations". Done. Caption must also specify what the red boxes indicate. Done.
• section 3. Please, start giving a general overview and intro, describing that drone flights were performed and specify the purpose of the flight at each study site- Technical details can be described after that intro 

Answer: We have modified these lines as suggested, trying to not anticipate technical details that are presented later. The original idea was to give the technical methods for all sites separately from the rest of the material.

New lines 184-196. Over a seven-year period, UAV surveys were conducted on three distinct environ-ments (Figure 1) that reflect specific sedimentary dynamics in transgressive domains: a parabolic migrating dune in Piscinas, Sardinia; a washover fan in Martignano barrier is-land, MGL; and a prograding spit in Tratauri bank, MGL.

The UAV surveys in Piscinas were meant to assess the migration of the parabolic dune after the winter season and describe its current state; the surveys in Martignano and the Tratauri Bank were designed to evaluate the post-storm evolution of a washover and determine the microtopography to support nesting bird monitoring.

• 179 "The first survey, conducted from November 19 to 24, 2014.." it is weird to read about 5 days for the pre-winter conditions, and just one day for the post-winter. I suggest to simplify. Perhaps," surveys were performed in middle Nov and middle May, dates corresponding to the start of winter and middle spring season, respectiveley"....something like this.

Answer:. We have modified the sentence as suggested. We understand that this difference in timing sounded wired, but there were reasons. To begin with, the battery life we had on the first flight had a significant effect on the entire duration of the survey. Second, we had more batteries and less time to survey in the second campaign, as well as adverse weather circumstances. We have not included these issues in the text to avoid making it too weighty to read.

New lines 218-221 In Piscinas, the first survey, conducted in November 2014, before the beginning of the winter season, covered the entire area of the parabolic dune, while the second, conducted in May 2015, in the middle of the spring season and theoretically after the strong winds period, focused on monitoring the migrating lobes.

• 182-183 "Each flight was processed as indicated above" no need of these sentences.

Answer: Ok, done.

• 185  in scientific papers, avoid being vague. "to highlight sand displacement", better "estimate"....Instead of "some profiles", specify the number. I would rather see the area in square meters, it is not very common to report ha in coastal/beach field.

Answer: We have modified the sentence as suggested.

• Table 1 caption must be detailed. All acronyms must be specified to help the reader (e.g., NT4). Better specify also "Image acquistion Overlaps" and" Image acquisition sidelaps"

Answer: We wrote a more detailed caption and specified the acronyms when possible. Some acronyms are names (for example the NT4 which indicate the aircraft model)

Table 1.  For each study site, the table reports the year of the UAV survey with the main characteristics of the cameras and flight plan, acquisition details, and output resolution.

• 178-233 is it necessary to report in the text all singular dates? the reading is quite tedious, and dates are in Table. Perhaps, the text can instead describe the frequency, for instance "Three UAV surveys were conducted in the Martignano barrier island between 2016 and 2021 (table1), to determine the evolution of a washover which was likely caused by the impact of two severe storms in 2012 and Feb 2013 [64]". ecc.

Answer: we removed the information on the dates from the study areas of Piscinas and Martignano and improved the text as suggested. However, for the Tratauri site, we felt that the dates of the surveys were necessary because they were represented in the results and would cause more confusion if compared at a later time.

• Section 4. I Verbs must be with past tense.

Answer: We have modified as suggested. Furthermore, in some cases, we improved the text to make it clearer.

• "it reaches from approximately 1.5 m above m.s.l. near the shore to almost 113 m near the southernmost portion of the dune." revise English. mAybe you meant "it rised".

Answer: we wish we had written the sentence more clearly. The idea was to provide a range of elevation within which the dune develops.

Lines 271-273: In addition, the landform varied largely in elevation, starting from approximately 1.5 m above m.s.l. near the shore to a maximum height of almost 113 m near the southernmost portion of the dune.

• Discussion. From my point of view, keeping highlighting the drone potentiality is not necessary, or at least, can be said just once in the text. In Discussion, it is missing also the limitation and potential lacks of the study, along with a fair evaluation of the surveys. Was the monitoring frequency sufficient, or more surveys would have given better info? Ecc

Answer: the Discussion section has been improved and separated from the Conclusions. There are still three sub-sections in the discussion, one for each site. It is concerned with the most significant coastal changes and processes affecting each case study, and we focused on a brief discussion on the limitations of our survey and monitoring, as well as an improvement hypothesis.

• 4 must be Conclusions, which are missing. Conclusions cannot be a resume of the methodology.It must resume the scientific achievements and understanding. In other words, Conclusions is what you understood from drone images.

Answer: as request, we wrote the Conclusion section, focusing on the meaning of the results of our surveys and getting a wider context to our results.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The subject of manuscript is interesting but manuscript looks somewhat weaker from perspective of novelty. 

The introduction section needs to be strengthen. 

You can take help of following for it. 

https://link.springer.com/article/10.1007/s12237-021-01001-5

https://www.mdpi.com/2072-4292/15/1/226

https://www.hindawi.com/journals/ace/2023/3544724/

There are many unexplained acronyms in the paper. Please introduce them .

In maps depiction of SI units of meters in scale is wrong. It should never in capital. Use 'metre'.

The study area is nicely introduced.

What are limitations of your study?

Authors can give a methodology flowchart in the paper.

The problem statement needs to be more refined.

 

 

 

Author Response

Dear Reviewer 2,

 

We are grateful for spending your time on reviewing our manuscript “Quantifying transgressive coastal changes using UAVs: dune migration, overwash recovery and barrier flooding assessment and interferences with human and natural assets”. The revised version of the paper has been changed according to your comments and the suggestions provided by the other Reviewer. We re-wrote almost entirely some parts of the work. It is our belief that the manuscript is substantially improved after making the suggested edits.

In synthesis, the most substantial changes are in the paragraphs:

Introduction: We updated the contextualisation with a new structure of this part and by citing new and more recent references in order to properly outline the scientific framework of our investigation. The aims of the article have been re-written for a more correct focus on the real content of our work.

Results: We increased the clarity of the findings explanation, especially in the sections 4.2 Martignano.

Discussion / Conclusion: As requested, we insert two separate section. The Discussion section includes three sub sections, one for each site. It is dealing with the most important coastal changes and process involving each case study and explored thanks to the UAV surveys. We paid attention to a brief discussion for each case study on the limit of our survey and monitoring and to an improvement hypothesis. The Conclusion section is focusing on the meaning of the results of our surveys in the three case studies and getting a wider context to our results.

 

We have transcribed all your comments in this text, with a point by point response, as reported below.

 

We appreciate your time and look forward to your response.

 

Best regards,

 

      Giulia Casagrande

on behalf of all authors

 

 

 

 

 

 

1. The subject of manuscript is interesting but manuscript looks somewhat weaker from perspective of novelty.

Answer: We have clarified the work's purpose. We are conscious that the work lacks novelty from a technology standpoint, but we think that comparing three case studies in transgressive contexts may add a valuable contribution to this research topic. Our cases are exceptional in Italy, where coasts are often developed and engineered. Indeed, the three cases have a high degree of freedom, and as a result, coastal processes can express rapid and significant morphological changes, with important impact on human and ecological assets.

2. The introduction section needs to be strengthen. You can take help of following for it.

https://link.springer.com/article/10.1007/s12237-021-01001-5

https://www.mdpi.com/2072-4292/15/1/226 https://www.hindawi.com/journals/ace/2023/3544724/

Answer: thank you for the suggestions; we improved the framework of our study with a new structure of this section and citing new and most recent references.

3. There are many unexplained acronyms in the paper. Please introduce them.

Answer: we realised we had used a lot of acronyms without defining them. Therefore, we have modified and indicated them in full. However, we have not intervened in some cases because they are names.

4. In maps, depiction of SI units of meters in scale is wrong. It should never in capital. Use 'metre'. Answer: done.
5. The study area is nicely introduced. Answer: Thank you.
6. What are limitations of your study?

Answer: we discussed some limitation in the new discussion section, according to the suggestion of Rev 1.

7. Authors can give a methodology flowchart in the paper.

Answer: the methodological section of the article is quite detailed, and there are already many figures in the manuscript. We attempted a graphical summary of the methodological section, but on our opinion it resulted unnecessary and trivial. We think that a flowchart in our paper is redundant. However, it is a highly subjective suggestion, and we leave it to the editor's discretion.

8. The problem statement needs to be more refined.

Answer: the aims of the article have been re-written and we attempted to be more detailed and emphasise the objectives of the work in all of its parts.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Manuscript:

Quantifying transgressive coastal changes using UAVs: dune migration, overwash recovery and barrier flooding assessment and interferences with human and natural assets

submitted by:

Giulia Casagrande, Annelore Bezzi, Saverio Fracaros, Davide Martinucci, Simone Pillon, Paolo Salvador, Stefano Sponza and Giorgio Fontolan

 

The advantages derived from the use of UAVs are well established, due to their cost-effectiveness and ease of use. In the article the Authors present numerous environmental applications, particularly when monitoring contexts characterized by rapid morphological changes and high rate of sediment transport, such as coastal areas.

 

The structure of the manuscript is considered and clear. In the introduction, the background and comprehensive review of the problem's literature were presented. The Authors present transgressive parabolic dune of Piscinas, and dynamic barrier islands of the Marano and Grado Lagoon. Results of the research have been presented in tabular and graphic form. Conclusions, on the basis of the research.

 

Following suggestions should be taken into consideration: 

Line 46: low-cost should be used rather than cheap cost

Line 81: [23-25] with no brackets

Line 88: [26-28] at the end of the sentence is enough - not (see [26-28])

Line 135: 15.61 m² s² should be corrected

Line 177: Reference source not found

 

Author Response

Dear Reviewer 3,

 

We are grateful for spending your time on reviewing our manuscript “Quantifying transgressive coastal changes using UAVs: dune migration, overwash recovery and barrier flooding assessment and interferences with human and natural assets”. The revised version of the paper has been changed according to your comments and the suggestions provided by the other Reviewer. We re-wrote almost entirely some parts of the work. It is our belief that the manuscript is substantially improved after making the suggested edits.

In synthesis, the most substantial changes are in the paragraphs:

Introduction: We updated the contextualisation with a new structure of this part and by referencing new and more recent references in order to properly outline the scientific framework of our investigation. The aims of the article have been re-written for a more correct focus on the real content of our work.

Results: We increased the clarity of the findings explanation, especially in the sections 4.2 Martignano.

Discussion / Conclusion: As requested we insert two separate section. The Discussion section includes three sub sections, one for each site. It is dealing with the most important coastal changes and process involving each case study and explored thanks to the UAV surveys. We paid attention to a brief discussion for each case study on the limit of our survey and monitoring and to an improvement hypothesis. The Conclusion section is focusing on the meaning of the results of our surveys in the three case studies and getting a wider context to our results.

 

We have transcribed all your comments in this text, with a point by point response, as reported below.

 

We appreciate your time and look forward to your response.

 

Best regards,

 

      Giulia Casagrande

on behalf of all authors

 

• Line 46: low-cost should be used rather than cheap cost.

Answer: This part of the paper is substantially changed.

• Line 81: [23-25] with no brackets.

Answer: ok, Thanks.

• Line 88: [26-28] at the end of the sentence is enough - not (see [26-28]).

Answer: ok, done.

• Line 135: 15.61 m2s2 should be corrected

Answer: We have updated the old bibliographic reported data (which was expressed in the not-so-usual form H²T²), calculating the wave power flux using the available wave data time series (11 years) and reporting the result in the more appropriate unit, kW/m.

• Line 177: Reference source not found.

Answer: ok.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Editor and Authors, the changes in the text were not returned highlighted in the second version. It is therefore quite difficult to evaluate the revised manuscript. I recommend Authors to return also the version with highlighted changes in future works. 

Overall, Objectives and Conclusions were well reworked, so aims and assessments are now clear. In Discussion, comments regarding limitations and possible improvements of the monitoring programs are missing, however the section was well re-structured. 

Finally, reference list was updated in Introduction, unfortunately in Discussion the comparisons with other works were spurious and not much relevant. For future works, I suggest to update the state-of-art.

Congrats on the work 

PS Fig.1 "we have added more information to the map (Italy and the Mediterranean Sea), which, along with the coordinates along the edge of the study sites, allows you to correctly identify places in the World" 

I still suggest to insert World location. Scientific papers have international audience which may not be familiar with european geography.