Evaluating Short-Term Tidal Flat Evolution Through UAV Surveys: A Case Study in the Po Delta (Italy)
Round 1
Reviewer 1 Report
The submission describes an interesting use-case of UAV-based photogrammetry, namely surveying of wetlands for understanding tidal flats and salt marshes. The presented approach is thorough (from an end-user perspective), there are some clear lessons learned, and the article has - in addition to the specific use-case - some interesting guidelines for the use of UAV-based photogrammetry. Among others, there is a very good discussion of the state of the art - at least from the perspective of a non-expert in the particular application domain. In addition to the conclusion for the relevant use-case of surveying of wetlands, the submission presents a very useful accuracy analysis, which should be of interest across many application domains - at least, according considerations are much too often missing in work on UAV-based photogrammetry. Overall, the submission is very pleasant to read. There are a few very minor glitches and typos, e.g.:
"...due to the floods of the 1950s and'60sThe 15 DSM accuracy was tested..." -> missing period '.'
"since the GCP density" -> spell-out GCP once it appears for the first time in the abstract
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
see attachment
Comments for author File: 
Comments.docx
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Review the abstract. Suggest on line 19, remove “resulted” and use “was”.
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
Here are some problems I noticed in the text:
“while Lidars” line 66
It is unclear what the authors mean when using the term “lidars.” I am not familiar with a plural form of the word
Contrast Malaria line 123 probably means combat malaria
Figure 3 is not of sufficient quality (resolution). I cannot read the text. Other figures are lower quality, but the text is readable.
“DJI Phantom Visual 3+” line 163, is not a DJI model I am familiar with. I tried a web search for this term and could not find it. The authors should reverify that the model is correctly named and reported in the article.
The system that the authors used to cite software (line 188, 199) does not seem to meet the journal standard format for citing software.
“crevasse splays structures” should be “crevasse splay structures” (line 321) In English there is no need to pluralize what is effectively the adjective of “structure”.
Figure 7 the subfigures b and c are identical. C is labeled as February 2019 - July 2019 in the figure, but July 2019 and February 2020 in the caption so it is likely just an error.
The term “important” in reference to changes is used throughout the article (435, 441, 487, 490). The authors do not define this term. Is it statistical significance etc?
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors have given a satisfactory response, which emphasizes the scientific of this manuscript. Some more minor changes are suggested：
- It is suggested to add the accuracy of RTK-GPS Trimble R8 in the manuscript (Answer 2.4)
- Please note that 3D reconstruction process （"Agisoft Metashape" software） adopts the built-in GPS and IMU pose data of these images, and the RTK-GPS data is used to correct the geographical deviation (Answer 2.5).
- If possible, please add relevant data proofs in the appendix of the manuscript, which will further improve the morphodynamic explanation (Answer 2.11)
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
