Coastal Dune Restoration: A Checklist Approach to Site Selection

Round 1

Reviewer 1 Report

The paper “Coastal dune restoration: A checklist approach to site selection” provides an application of various metrics/indices to describe the dune state base don the ecology, geomorphology and level of management. Synthesizing multiple metrics/indices allowed for the development of measures to determine recommendations of dune where to invest in dune conservation, restoration, or where dunes have been so degraded that allowing natural processes to rebuild would be more cost effective. Their approach provides a user-friendly approach to translating science into management.

Over all the paper is very well written and easy to read by a broad audience. I have some minor suggestions for the authors. I suggest adding some information in the objectives about the resulting index from this paper being a revision and adaptation of indices from Garcia-Lozano et al. In the methods it is mentioned that this has been tailored to urbanized coasts in the Mediterranean region, but it seems this could this be scaled out to other global systems perhaps with modifications of certain value ranges (i.e., dune crest height for dunes that tend to grow to different heights than in this region). In the methods, a description of how the variables differ from Garcia-Lozano et al. would be useful for readers (or this could be detailed in the supplementary file). Are the groupings of the different variables (StaDun, BeaPot, CoMan) unique to this paper?

This paper discusses the high impact of tourism, development, etc in many areas of the coast (presumably the areas labeled for renaturalisation), but perhaps another term could be applied rather than renaturalising an area, such as investing in other management efforts (grey engineering/active management).  The rationale for this is that an index that identifies the best areas to conserve or places that have a high potential to develop dunes is very useful, but when communicating to the public or policy makes, stating areas of high economic development should be renaturalised may not be taken well and thus, reduce the impact of the index.

Please define TypeIII plants in the table heading (you give a definition later in the methods, but it is not as well known of a term.

Line 469 do you mean renaturalisation?

Author Response

#Reviewer 1: The paper “Coastal dune restoration: A checklist approach to site selection” provides an application of various metrics/indices to describe the dune state base on the ecology, geomorphology and level of management. Synthesizing multiple metrics/indices allowed for the development of measures to determine recommendations of dune where to invest in dune conservation, restoration, or where dunes have been so degraded that allowing natural processes to rebuild would be more cost effective. Their approach provides a user-friendly approach to translating science into management. Overall, the paper is very well written and easy to read by a broad audience. I have some minor suggestions for the authors.

#Authors: We would like to thank the Reviewer for the comments on the manuscript.

I suggest adding some information in the objectives about the resulting index from this paper being a revision and adaptation of indices from Garcia-Lozano et al. In the methods it is mentioned that this has been tailored to urbanized coasts in the Mediterranean region, but it seems this could this be scaled out to other global systems perhaps with modifications of certain value ranges (i.e., dune crest height for dunes that tend to grow to different heights than in this region). In the methods, a description of how the variables differ from Garcia-Lozano et al. would be useful for readers (or this could be detailed in the supplementary file).

#Authors: Thank you for your suggestion. We added a table in the Supplementary to highlight differences with indices from Garcia-Lozano et al. (2020)

Are the groupings of the different variables (StaDun, BeaPot, CoMan) unique to this paper?

#Authors: The partial indices that we considered (StaDun, BeaPot, CoMan) grouped variables according to Garcia-Lozano et al. (2020) in order to separately summarise features of i) the current conservation status of the dune system (StaDun), (ii) the potential of a given beach stretch for a dune system (BeaPot) and (iii) the impact of management practices (CoMan). Although some variables were modified with respect to Garzia-Lozano et al. (2020), these were consistently merged with the features summarised and described by each partial index.

This paper discusses the high impact of tourism, development, etc in many areas of the coast (presumably the areas labeled for renaturalisation), but perhaps another term could be applied rather than renaturalising an area, such as investing in other management efforts (grey engineering/active management). The rationale for this is that an index that identifies the best areas to conserve or places that have a high potential to develop dunes is very useful, but when communicating to the public or policy makes, stating areas of high economic development should be renaturalised may not be taken well and thus, reduce the impact of the index.

#Authors: Thank you for your comment. The class names of the CMR index were defined according to the “Management Framework" proposed by Garcia-Lozano et al. (2020). The sectors labelled “Renaturalisation” are those in which both BeaPot (i.e., the natural potential of a beach to host a dune system) and CoMan (i.e., coastal management practices) need to be improved. While the terms 'Restoration' and 'Recovery' refer specifically to the coastal dunes, “Renaturalisation” refers to the management framework that applies to the entire beach dune system. For this reason, we would prefer maintaining the term “Renaturalisation”, as it is a reminder of the need to 'restore natural processes' in order to sustainably maintain a dune beach system (and tourism).

Please define Type III plants in the table heading (you give a definition later in the methods, but it is not as well known of a term).

#Authors: Thank you for your suggestion. We added the Type III species definition in the Table 1 heading as indicated.

Line 469 do you mean renaturalisation?

#Authors: Thank you for pointing out the error, which we have corrected.

Author Response File: Author Response.docx

Reviewer 2 Report

The authors submitted an interesting manuscript dealing with dune restoration. However, the manuscript should be revised and improve it especially its structure. Below are some comments and suggestions to improve the overall quality of the manuscript:

Line 85: In the section introduction, the authors should provide a brief review of the studies conducted and dealing with the proposed index of “dune restoration potential”. Such information would help readers better understand its improvement and the novelty of this study.

The section 2 Materials and Methods is not well structured. The authors should better describe the section of Material and Methods. On line 121, the authors are mixing the description of methodology and the data. They should have a section of dataset description and provide all the details necessary for such date of acquisition, spatial resolution, spectral resolution for satellite images (lines 155-157) or orthophotos, and other data used and the parameters extracted from them. And after they should provide the subsection of Methods and indicate the methods used to obtain the results by analysing these datasets.  

In the section of the results the authors should put the Figures and the Tables in the text near where they cited in the manuscript. This would help readers better understand the results.

Lines 375-478: The authors should provide two separate sections, one for the discussions and the other one summarizing the main conclusions.

Lines 61-62: Please provide recent references:

please refer to (1) Muzirafuti, A.; Randazzo, G.; Lanza, S. UAV Application for Coastal Area Monitoring: A Case Study of Sant'Alessio Siculo, Sicily. In Proceedings of the IEEE International Workshop on Metrology for the Sea: Learning to Measure Sea Health Parameters, MetroSea 2022, Milazzo, Italy, 3–5 October 2022; pp. 143-147. ISBN: 978-166549942-2. doi: 10.1109/MetroSea55331.2022.9950841. (2) Halls, J.N.; Frishman, M.A.; Hawkes, A.D. An Automated Model to Classify Barrier Island Geomorphology Using Lidar Data and Change Analysis (1998–2014). Remote Sens. 2018, 10, 1109. https://doi.org/10.3390/rs10071109. For beach nourishment and dune movement analyses.

Best regards

Minor editing of English language are required

Author Response

#Reviewer 2: The authors submitted an interesting manuscript dealing with dune restoration. However, the manuscript should be revised and improve it especially its structure. Below are some comments and suggestions to improve the overall quality of the manuscript.

#Authors: We would like to thank the Reviewer for the comments and suggestions on the manuscript.

Line 85: In the section introduction, the authors should provide a brief review of the studies conducted and dealing with the proposed index of “dune restoration potential”. Such information would help readers better understand its improvement and the novelty of this study.

#Authors: Thank you for your suggestion. We have improved the introduction by adding a brief overview of the current “state of the art” on indices and gaps in order to better contextualise our study within the existing literature.

The section 2 Materials and Methods is not well structured. The authors should better describe the section of Material and Methods. On line 121, the authors are mixing the description of methodology and the data. They should have a section of dataset description and provide all the details necessary for such date of acquisition, spatial resolution, spectral resolution for satellite images (lines 155-157) or orthophotos, and other data used and the parameters extracted from them. And after they should provide the subsection of Methods and indicate the methods used to obtain the results by analysing these datasets.

#Authors: Thank you for your comment. We have reorganised section 2 Materials and methods according to your suggestions. In particular, we have further subdivided the section by adding a section for data analysis to separate data collection and analysis. However, because of their length, it was not possible to include all information on data collection for all indicators: Details on the orthophotos (included acquisition date, resolution and reference) were included in the Supplementary tables, as well as all information on the assessment of indicators not based on orthophotos (e.g., those related to vegetation, beach sediments, climate and management).

In the section of the results the authors should put the Figures and the Tables in the text near where they cited in the manuscript. This would help readers better understand the results.

#Authors: Thank you for your observation. We reported results in the form of both images and tables to facilitate the visualisation and interpretation of the results obtained. However, due to the large number of sectors analysed, it was not possible to create different tables (i.e. one for each index). For this reason, we preferred to create different images for each (partial) index, placed near the respective section, while we put all values in a single table to avoid multiple large tables. Particularly, the table showing assessed values for each partial indices and assigned classes for CMR and DEP was moved in Supplementary (Table S7). Moreover, when contacting the journal, we will ask to place the remnant tables of the main text in such a way that they are not split between two different pages and to adapt the size of the images to the width of the paragraphs.

Lines 375-478: The authors should provide two separate sections, one for the discussions and the other one summarizing the main conclusions.

#Authors: Thank you for your suggestion. We created the Conclusions section.

Lines 61-62: Please provide recent references:

please refer to (1) Muzirafuti, A.; Randazzo, G.; Lanza, S. UAV Application for Coastal Area Monitoring: A Case Study of Sant'Alessio Siculo, Sicily. In Proceedings of the IEEE International Workshop on Metrology for the Sea: Learning to Measure Sea Health Parameters, MetroSea 2022, Milazzo, Italy, 3–5 October 2022; pp. 143-147. ISBN: 978-166549942-2. doi: 10.1109/MetroSea55331.2022.9950841. (2) Halls, J.N.; Frishman, M.A.; Hawkes, A.D. An Automated Model to Classify Barrier Island Geomorphology Using Lidar Data and Change Analysis (1998–2014). Remote Sens. 2018, 10, 1109. https://doi.org/10.3390/rs10071109. For beach nourishment and dune movement analyses.

#Authors: Thank you for your suggestion. We added the two studies indicated and updated the References.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

No further comments

Minor editing of English language are required