Integration of Earth Observation and Field-Based Monitoring for Morphodynamic Characterisation of Tropical Beach Ecosystems

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Key Issues and Manuscript Deficiencies
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There is no information of the exact dates/hours when the videos used for the analysis of the wave climate in the methodological section. All is mentioned is that “videos where captured for at least 10 wave periods”
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The authors shall refer in their introductory part to this special type of beaches that in bibliography are described as perched beaches (i.e. beaches protected by natural shallow submerged structures like coral reefs, which act similar to breakwaters providing effective protection to the coastal environments they front). Suggest referring to the papers of Shari L. Gallop and other coastal scientists who have significantly contributed on the understanding of these important coastal environments (see lines 60 – 63)
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Figure 1: Suggest to add reference of the coordinates used here. Text shown within the map shall be in english. Also, Figure 2, can be incorporated with Figure 1.
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Figure 1 and Figure 2 can be incorporated into a single Figure. Also, instead of showing just a picture of the beach, it would be interesting to show single frames from the videos used for the wave analysis.
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Lines 181-185: Here, the different satellite datasets used for applying the CoastSat algorithm are poorly mentioned. There is no information about i) which satellite (image) was used for shoreline extraction and at which date; ii) the resolution of each satellite image; and iii) the differences in shoreline extraction for each different satellite when applying the CoastSat algorithm. As this is the “key dataset” of this work. This things should be clearly presented and addressed by the authors.
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Section 2.2 is named as “Secondary Data collection”, whereas section 2.3 is named as “ Primary Data Collection”. This is very confusing for the reader. Section 3.2 is named as “Comparing beaches” and 3.2.1 as “Deriving wave characteristics with OFTV”. The use of english is very poor and in general the structure of manuscript needs to be appropriately re-arranged.
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Table 1. This poor table shall also be excluded and this information could be easily incorporated within the text.
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Lines 222 – 230: As these videos are an important part of this work, an example shall be shown in the manuscript (at least single frames from the two different videos), showing also the incoming waves.
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Table 2: There is no reason to add a table for 14 words. This information shall be included within the text
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There are methodological parts in this work that are not clear or/and sections presented in the results section, which should be in the methodology section. For instance:
o
Lines 280 – 285: This is clearly methodology
o
Lines 345 – 354: This is clearly methodology
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Figure 3: In the results presented here, there is no information about the exact dates of the satellite images used for shoreline detection. The dates used for shoreline detection shall be denoted in the figure as points. A table showing i) the exact dates and time of the satellite images; and ii) the satellite from which each image used for detection was derived and its technical characteristics (resolution).
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Figure 5: Here, the peak wave period derived from the OFTV analysis is compared against the results of the the WWIII model. The point for which data of the WWIII were extracted shall be shown at the study area figure. Also, these key question arise “Why there is no information regarding the wave heights within the manuscript ? “. “What is the effect of the reef(s) in wave attenuation at the nearshore as the videos capture this effect ? “.
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There is a need for substantial improvements regarding the use of english. A few noticable examples are the following:
Line 53
Suggest to replace the following: “ ..linked to erosive geomorphological behavior”
With “ ..linked with erosional behavior”
Line 56
Suggest to replace the following: “ ..especially vulnerable” with “ ..particularly vulnerable”
Lines 59 - 60
“..due to their naturally dynamic conditions”
What is the meaning of this, please specify and re-write appropriately
Line 60 - 63
Replace “….critical natural services” with “ …critical ecosystem services”
Line 109
Suggest to replace
“…due to their closeness to the shoreline” with “ … due to their proximity to the shoreline”

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript presents a compelling and practical multi-platform toolkit integrating Earth Observation data, Optical Flow Tracking Velocimetry (OFTV), and in-situ field measurements to monitor morphodynamic processes of tropical beaches in Panama’s Bocas del Toro Archipelago. The following suggestions are requested to imporve the manuscript

Line-by-Line Comments

L12-13, Briefly specifying the nature of this “novel approach” upfront (e.g., “using low-cost smartphone video and satellite data”) to give immediate clarity.

L17, “Optical Flow Tracking Velocimetry (OFTV) is applied to Smartphone camera footage…”

Comment: Capitalize “smartphone” only if it’s part of a product name. Otherwise, lowercase is standard.

L24, The term “well-sorted” may seem contradictory with “coarser” sediments, please rewrite

L67-69, The authors are requested for citing a specific cost range or operational limitation to better emphasize the barriers in resource-limited settings.

L105-122, (Data and Study Sites):

It is encourgaged to provide a small summary table listing each site, its key characteristics (for example wave energy, beach length), and geographic exposure.

L137-140, “Little to no secondary data is available regarding the morphology of the selected sites…” try to expanding briefly on the implications of this data gap for long-term monitoring and management.

L205-221 (OFTV methodology), This section is well-written. However, a flowchart or diagram showing the OFTV processing pipeline from video capture to velocity analysis would provide more comprehensive thing.

L245-249,  a brief rationale for why this transformation is used and what the slope of these CDFs implies about beach dynamics.

L303-305, Try to provide examples of these “other factors” (e.g., tidal currents, anthropogenic activity) to give readers more context.

L409–411, This point could benefit, perhaps include why the wave period might not align consistently (e.g., limitations of OFTV temporal sampling).

Line 440–441,  Provide some information that future work could incorporate human activity mapping or drone-based 3D models for shoreline structure to address this.

L521, please briefly specify what kind of geomorphological or weather patterns (e.g., offshore reef formations, trade winds) might be responsible.

L543-545, A great closing point. Please try to emphasize its replicability or scalability for other developing nations with similar environments.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors, this new version of the manuscript is significantly improved following the previous comments. However, there are some points that think need to be addressed as follows:

Lines 79 - 93 (Introduction): Here, the limitations of using in-situ data deriving from buoys is mentioned. However, there is no reference to the use of modeling outputs (e.g. Copernicus Marine Service). Such products are freely available and commonly used by many scientists who validated these models against in-situ measurements in several locations around the globe. This should be mentioned as you also make use of the Wavewatch III model output. 

Figure 1: Correct from Playa El Ismito to Playa Ismito (or opposite). Be consistent

Lines 419 - 466 (Coastsat and tidal correction) : Briefly refer how many images were used per satelite (Landsat 7- Sentinel 2), shown in the Appendix.

Table 1: Be cautious with the decimal precision. In estimation of wave velocity through OFV don't think that this method as a two digit precision. The same for Avg RoC estmated from the satelite images. 

Figure 3: Suggest to show the dates of image retreival as scatter points, in the same plot, to help the reader identify the results shown in this graph.

Results and Discussion: As Landsat 7 and Sentinel 2 images have a spatial resolution of 30 m and 10 m, respectively. This logically shall affect the use of CoastSat algorithm in your analysis. How does this affected your analysis and what are the limitations, advantages/misadvantages of the different satelite images used ? This should be described in the results sections and discussed more analytically in the discussion section.

 

 

Author Response

Please see the attachment. The msot recent changes in the manuscript are outlined in green.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The authors successfully response each points

Author Response

We would like to thank the reviewer for taking the time to review our manuscript.