Capability of Phenology-Based Sentinel-2 Composites for Rubber Plantation Mapping in a Large Area with Complex Vegetation Landscapes

Round 1

Reviewer 1 Report (New Reviewer)

Nice work! Please take the effort to rework and make it even better.  Some detailed comments: 

19 "pan-Hainan composites "--> this is unclear, better to write  "images of the island of Hainan

166: please remove table 1 with the detailed cloud cover statistics: One or a few  numbers is enough to illustrate the high cloud coverage rates. Better to discuss what is the maximal coverage you could still use.

179: Also add a number and comment on the cloud coverage of MODIS (how high, how many useful observations? )

216: the august 2017 data was collected outside the timespan of the images used. please comment on how temporal changes might influence your results. 

270 the J-M distance assumes a normal distribution of your data. Is this valid? 

413 the area weighted accuracy can be  omitted: everybody understands how weighted averages are made;

424: area weighted accuracy is not a percentage ! ( remove it)

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report (Previous Reviewer 1)

The manuscript has been revised and marked based upon the first version, but I do not see your specific responses to the previous review comments/suggestions, which make me difficult to judge whether the revisions have adequately addressed the reviewers' comments/suggestions. In general, the authors have modified the manuscript structure, and improved the introduction and methods. However, there are still two major problems: (1) Too many English writting issues (must improve); (2) the downscaling method for Sentinel-2 20m images to 10m images is not professional and acceptable. Other specific comments are listed below:

 (1)    Language issue: there are still substantial English expression issues throughout the manuscript. I just point out some of them and authors still need to find out and revise the rest. English writing must improve; otherwise, it is difficult to understand the manuscript.

(2)    Line 15: "is still challenged by" should be replaced with "is still challenging in the".

(3)    In the abstract: the classified rubber plantation area should be mentioned as a result.

(4)    Line 36: “Hevea brasiliensis” is a Latin name of a tree species, Italics should be used: “Hevea brasiliensis”

(5)    Line 69: “researches” should be “studies” since research is a countless noun.

(6)    Line 81: “on Hainan Island” should be removed.

(7)    The issue for downscaling 20m band to 10m has not been revised. Since your study emphasizes the 10m resolution, the simple resampling method using nearest neighbor is not acceptable. The SNAP software has specifically designed algorithms to do the downscaling of Sentinel-2 bands, and can be easily applied.

(8)    Line 290: should be Mean Decrease in Accuracy

(9)    Section 3.1: Many references are cited here. Generally, no citations are allowed in the Result. If you want to compare the similarity or dissimilarity, you can move these sentences with citations to the Discussion section. If these citations are for methods, then you should move to the Method section.

(10)Some places use “Hainan Island” while some places use “Hainan Province”. Please keep consistent. “Hainan Province” may be more appropriate.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report (Previous Reviewer 2)

The authors addressed all the comments through an extensive revision.

The revised manuscript has been improved significantly.

The authors must include in the discussion, a statement/references about the implications of independent variables correlation in RF importance in terms of robustness and reliability. This is well know issue and their are plenty of works on this

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report (Previous Reviewer 1)

The authors have addressed most of my comments and suggestions. The manuscript has been greatly improved, but there are still plenty of language issues. So I suggest a minor revision and authors need to continue improving the English writting. 

Author Response

The authors have addressed most of my comments and suggestions. The manuscript has been greatly improved, but there are still plenty of language issues. So I suggest a minor revision and authors need to continue improving the English writing.

Answer:

Thank you for your comments.

The manuscript has been revised carefully to correct the mistakes and improve the English expressions.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Please see the attachment

Comments for author File: Comments.pdf

Reviewer 2 Report

There is a profound need for manuscript proofreading and revision of English language usage

A great part of the introduction deals with the specific characteristics of the study area. Instead, earlier studies, relevant to the topic of the research are not presented in-depth.

Section 2.2.1. Sentinel 2A, already incorporates topographic correction. In addition the authors do not provide any info for the method they employed!

Section 2.2.1. There is no such thing as “vegetation-moisture indices”

Section 2.2.2. The MODIS data has significant coarser resolution, compared to S2 data.

Section 2.2.4 It is not clear, why the statistical yearbook data was used!

Section 2.2.5 Again this section is poorly written. Did the authors visited the field or they extracted samples from Landsat-8 and S2 images?

Section 2.3 Contains both methods and results. The MMU for homogenous samples (0.1 km2) is relatively coarse for the MODIS scale. In addition, how did the authors know, that the whole patch is homogeneous in terms of land cover

Section 2.5  Contains both methods and results.

Section 2.7 If correlation exists in the dependent variables, the RF importance measure is not reliable

Section 2.8.  Statistical data validation is not a robust measure of classification accuracy for RS spatial explicit studies