Vegetation Dynamics Due to Urbanization in the Coastal Cities along the Maritime Silk Road
Round 1
Reviewer 1 Report
This is an interesting paper that assesses an important application of satellite remote sensing for evaluating urban ecological changes at a very broad spatial scale. Your use Landsat to identify patterns of vegetation cover at a close to global scale is meaningful and could provide some useful knowledge and insight into coastal ecosystem response to human related impacts. These are all aspects of the study that I really liked. I also see the challenge of addressing global issues using geospatial tools with a level of accuracy and confidence. Therefore, I feel like you will really need to make this research and manuscript a clear and highly understandable/interpretable presentation of what you did.
I feel like this paper has the potential to be a nice contribution to the science of remote sensing and its application to the human-ecological interface. It uses statistics to justify the results which is good. What I think it lacks is detail in what was done and why. The methods need to be more clearly presented. The results and discussion are pretty good with providing the results, but I feel are more weak in the discussion of its relevance and tie to other research. Finaly, there are many issues with sentence structure, content and grammar. I am happy to help out with this, but this will need to be addressed before this paper can be published.
Here are some specific comments that should be addressed prior to consideration for publication:
Page 1, Line 14: change to “Substantial research indicates the effects of urbanization on vegetation cover, however, a view of this scenario from a regional scale is absent.” I would not include the “coastal area of the Maritime Silk Road” here because that is too specific. Start with the general need for information on scale and then show how you apply it to the study area of the MSR.
Page 1, Line 16: I would recommend inserting here a clear objectives statement before launching into the methods. What exactly are you intending to do with this study and why (overall). Once that is established, then it makes sense to start describing your work in capturing the effects of rapid urbanization on vegetation dynamics within the MSR.
Page 1, Line 16: what do you mean by “attempted”? It sounds like you tried, but possibly failed at accomplishing this. I would recommend rewording this to more clearly express what you did and then portray the results accordingly.
Page 1, Line 17: the way this is written makes it sounds like you are referring to someone else’s research. I would state something like “We calculated spatio-temporal trends of vegetation dynamics along a UDI gradient using MODIS EVI.” Spell this out of course. In line 19, you could then say “We found a significant reduction of EVI in the core area…” I think this would be a more clear way to express your research.
Page 1, Line 25: before you state the need for additional work, I would provide some aspect of what contribution your research makes. What does it do to improve our current understanding or how can we better measure because of this. Then state the value of further work.
Page 1, Line 31: rewrite as “In recent decades, urban centers have developed within coastal zones and cities, becoming an important component of the economy in these coastal states or provinces [1].”
Page 1, Line 33: I am not sure I would use the word hinterland. Its not clear what this means. Also, consider stating it something like this - “Coastal cities constitute critical gates into the hinterland where they serve as economic centers providing amenities and services for human-related activities including tourism, transportation and fishing.”
There are a great number of small grammatical issues that should be addressed throughout the paper. If you want help with this, please send me a word document that I can edit with track changes. I will focus from here on out on the content and structure of the manuscript, but need to emphasize the importance of writing in a way that is clear, understandable, and meaningful.
Page 2, Line 51: It states here that vegetation plays an important role in urban systems. So far this paper has focused on coastal areas, but this isn’t stating that so clear. I would either put this paragraph forward before you go into coastal systems, or focus this paragraph on more coastal vegetation issues. You do emphasize mangroves and other coastal values from vegetation, but the beginning is not so clearly linked.
Page 2, Line 90: I do like that you have an identified objectives statement. I would recommend that you start by clearly stating what the overall purpose (justification) of your research is and then go into the specifics (investigation of urbanization of 35 cities…). Also, you will need to work on the clarity of the writing as mentioned earlier.
Page 4, Line 144: Its not clear to me what you mean by “Remote sensing products”. I would state this heading more clearly. Maybe just remotely sensed image acquisition or something like that.
Page 4, Line 145: I would emphasize the need to be consistent in using first vs third person verbiage. I would state here “We obtained land cover maps from 35 coastal cities for 2000, 2010, and 2015…”. Also, you should explain why you selected these years. Why did you select these and the uneven interval that they represent?
Page 5, Line 157: what do you mean by “deep analysis”? Is this a type of analysis or are you trying to say that is a more computationally demanding analysis (something like that)?
Page 6, Line 191: I feel like you would benefit from a little more detail in the methods. The discussion of how you obtained the imagery is ok, but I kind of felt a lack of understanding when it comes to the UDI (how it was created, what steps you took to get there, what it is used to accomplish. That could be applied to the EVI as well. Also, go into more detail on the accuracy assessment that you refer to in the results section (Line 196). How was this method conducted? Provide some details to this. I think a more clear explanation of the use of linear regression to assess cities and their patterns would also be helpful.
Page 7, Line 227: since you are combining results and discussion, I think it would be helpful for you to provide more interpretation of your results in light of your observations and related literature. For example, you state that some cities had a higher EVI in urban areas, but don’t really explain why this would happen or its implications. Is this expected or a surprise to you?
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The work is quite novel and interersting. However, there are important corrections to be made. Please rectify the manuscript in accordance with the comments submitted to the editor.
Comments: This manuscript tries to reveal the relationship of the Enhanced Vegetation Index (EVI) along the Urban Development Intensity (UDI) regions in different cities. The theme is quite novel. However, the work is poorly written and presented. Substantial improvements are required in english writing, use of appropriate words to convey the main concept to the readers.
The authors need to elaborate more on the concept of EVI.
In fig 2, authors have proposed the different forms of EVI-UDI models, i.e., convex, concave and linear curves, which is quite interesting. If this concept already exists in scientific literature, the authors need to mention the source citation. However, if this kind of distinction is made for the first time ever, authors need to explain the logic in detail, specifically, why would some cities exhibit convex and concave patterns. This explanation must be visible close to the fig 2 for the comprehension of the readers.
Surprisingly, the authors have not shown EVI-UDI model curves for any of the cities. The authors have mentioned about the cities that exhibit these different curves, but the actual curves are not shown. Why?
What is the cause of sudden increase in ΔEVI of jakarta in 2005-2006?
ΔEVI for desert cities is close to zero or slightly higher. this is due to low vegetation in desert rural areas. however, kolkata exhibits high ΔEVI (>0) for all UDI classes throughout the study duration. Why? even if it is assumed that urban areas have too much vegetation in this city, the rural vegetation is still very high around kolkata.
Fig 1 can be improved. Labels should be more carefully placed. Tiling on background image is not required. Relevant country outlines would be more appropriate.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments are attached
Comments for author File: 
Comments.docx
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
This paper has been effectively revised and the authors have addressed my comments and concerns from the first review. The paper is in much better condition and is a meaningful contribution to the science of image classification to detect changes in land cover. I think there will be a broad audience interested in this research.
I reviewed the paper carefully again and did not detect any major issues with study design, statistics, and organization. I did find a number of minor edits that should be addressed prior to publication. The are as follows:
Page 2, Line 49: this sentence should be reworded to “…the development of ports leads to the development of coastal cities.”
Page 2, Line 50: its not clear what you mean by rising scale. Do you mean the increasing size of ports? Also, change the wording to “…and transportation of ports has marked the rapid expansion and economic development of coastal cities in recent decades [5]. This rapid urbanization…”
Page 2, Line 52: I think you mean to say “increased coastal erosion”.
Page 2, line 58: change this wording to “…and are home to a large number of plant and animal species.”
Page 2, Line 72: I recommend you reword this to state “EVIs are generally less likely to become saturated in high…” That’s if this is what you are trying to say. I am not totally certain what you mean by “are generally lower to avoid saturation”. You should clarify what this suggests.
Page 2, Line 83: change the word “treats” to “threats”
Page 2, Line 85: its not clear what you mean by “vegetation ecosystems”. Most terrestrial and many marine ecosystems are vegetated. Maybe you mean to state “vegetation structure” or just “ecosystems”.
Page 2, Line 90: change “Among the pressures,…” to “Among these pressures,…”
Page 2, Line 91: change “…are the most important emergencies.” To “… are of greatest concern.”
Page 2, Line 93-94: I would write this to state “The MSR has special economic and ecological characteristics, and covers a wide range of climates, ranging from subtropical to tropical, desert, and Mediterranean.”
Page 2, Line 94: It not clear what you mean by “These push the investigation of vegetation from coastal city urbanization…”. Can you help clarify this? I am not sure what to suggest since I don’t understand what it means.
Page 3, Line 103: I would recommend changing the word “grasp” to “assess”
Page 3, Line 135: Consider changing the wording to “…world’s major oil export and agricultural product import areas.”
Page 6, Line 203-205: the caption for figure 1 is left justified. This one is centered. I would recommend that you left justify this sentence.
Page 6, Line 206: consider restating this as “where a indicates that the EVI was convex (a<0) or concave (a>0).”
Page 6, Line 217: I would reword this to say something like “Land cover types common between all 35 coastal cities was classified into 5 cover classes…”. I just know that the wording “Land covers” is not grammatically correct.
Page 10, Line 308: I think you will want to left justify this table description. Its not common to center this.
Nice work and I commend the authors for improving the paper and their work on this important subject.
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
good luck
Reviewer 3 Report
This revised version is much improved.
Author Response
Thank you very much for all your help in the revision of the manuscript.
