Using Earth Observation for Monitoring SDG 11.3.1-Ratio of Land Consumption Rate to Population Growth Rate in Mainland China

Round 1

Reviewer 1 Report

Comments are attached in document.

Comments for author File: Comments.pdf

Author Response

Dear Reviewers,

Thank you for your letter and comments concerning our manuscript entitled "Using Earth Observation for Monitoring SDG 11.3.1- Ratio of Land Consumption Rate to Population Growth Rate in mainland China" (remotesensing-680275).

The comments were valuable for improving our manuscript and guiding our research. We have studied the comments carefully and have made revisions accordingly. We hope that the revisions meet with your approval and please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript is well written with a clear presentation of theory, methods and results. Figures are clear and readable with fair selection of colours and symbology. Data processing and results are sufficiently described and presented.

I believe it can be published at it's present state.

Author Response

Dear Reviewers,

Thank you for your comments concerning our manuscript entitled "Using Earth Observation for Monitoring SDG 11.3.1- Ratio of Land Consumption Rate to Population Growth Rate in mainland China" (remotesensing-680275).

The comments were valuable for improving our manuscript and guiding our research. 

Reviewer 3 Report

The research presented in the manuscript seems to be carried out well. Results are generally well presented. The discussion is convincing, with the best part being the comparison with previously published research and other datasets.

The methodology is definetely the part that requires more revision. There the authors need to clarify some key points that I have recalled in the below line-by-line comments, in addition to other minor things:

- lines 28-30: the sentence (particularly after the comma) is not very clear
- line 31: what is "the land expansion rate"?
- line 32: what is "uncoordinated development"? what do the authors mean with this term?
- Lines 33-35 seem to be a repetition of the previous sentences
- From the abstract it is not clear what EO data have been used. They should be mentioned.
- The keyword "Remote sensing" seems to be very generic. Furthermore, no keywords referring to the specific EO data used are currently included, while they should be
- Lines 46-47: the meaning of this sentence is not clear. What do they authors mean with "deepening"?
- Line 55: "a mutual interdependence and influence still exists" should probably be "a mutual interdependence and influence still exist"
- Line 57: "As cities continues to expand," should be "As cities continue to expand,"
- Line 65: "a plan for the future city growth should be planned" - the use of "plan" and "planned" so close do not sound well
- Line 74: as highlighted in a previous comment, the term "coordinated" should be explained
Line 77: "scare" should probably be "scarce"
- Line 79: the citation to reference [7] is not correct because the reference the authors are referring here is not numbered (see p. 20). Therefore, the references numbering in the remainder of the text is not correct.
- Line 87: please clarify the concept of "sample cities"
- Line 93: according to this sentence, the authors consider China a developing country. However, given the industrial revolution happened in China, there is literature debating whether China can be still considered a devleoping country, while it should be considered a developed country. The authors should clarify their position in this regard, especially if they refer to today's China and not the China of a couple of decades ago.
- Line 149: "exceeded" should be "exceeding"
- Lines 160-161: please explain better and in more detail how the populaton has been calibrated in those administrative divisions that changed across the 20-year period of study
- Line 166, formula (1) cointains a typo, the bracket ) after Urbt+n is not necessary. Furthermore, I recommend to revise all the formulas because in the official SDG metadata document time t refers to "the past/initial year" and time t+n refers to "the current/final year" https://unstats.un.org/sdgs/metadata/files/Metadata-11-03-01.pdf
In the current manuscript the authors seem to have referred times t and t+n differently
Additionally, the SDG formulas refer to "total population within the city" and "total areal extent of the urban agglomeration". Given the methodology described in sections 2.1 and 2.3 and the authors' statements at lines 131-137, the authors have modified the formulas. This needs to be better explained here.
- Line 178: I am a bit confused. If LCRPGR is LCR / PGR, when LCR is positive and PGR is negative, their ratio will be negative. So LCRPGR cannot be > 1 as stated by the authors. Please clarify.
Lines 181: "are is" should be "is"
Lines 183-184: please be consistent because in the text the term "toward" is used, while "towards" is used in Table 2
Figure 1: the caption should contain the notation of all the acronyms.
Line 196: please clarify what reference [32] is. Searching it on internet I found this publication https://www.springer.com/gp/book/9789811307782. Is this the reference you wanted to cite? If so, which chapter contains the methodology you used to derive the built-up areas?
If the reference refers to a different document, please modify the reference to provide the necessary bibliometric information.
Lines 203-206: it is not clear what the six layers are and how they are derived. Please rewrite this sentence and be more explicative
A more general comment: Figure 1 and the text from line 194 to line 222 are not very well connected. The text is organised according to a step structure with 3 steps. But these steps are not graphically displayed in Figure 1. This makes very hard to relate the text to the figure. Furthermore, the layers and correlation coeffiecients mentioned in the text are not reported in the flowchart figure.
I recommend to revise thoroughly this section and Figure 1.
Lines 224-229: I cannot find reference 33 in internet or researhc catalogue. Please revise the reference. Furthermore, please justify why 2010 has been chosen as the reference year to divide the Chinese cities based on size.
Lines 227-229: please add in the supplementary materials the whole list of the 340 cities divided according to these size classes.
Line 233: the average LCR values for the two decades considered are very close to 0. Are these average values really statistically significant to state the averagely there was a positive growth? or, instead, the so low values cannot be assumed as a relevant statistics?
Figure 2: I think the figure should be better described in the caption. My understanding is that on the left the spatial distribution of the LCR is reported at grid level and city level for the decade 1990-2000 (i.e., figure 2a and c, respectively), while the corresponding spatial distribution on the right (i.e., figure 2b and d, respectively) refer to the decade 2000-2010. Is that correct? If so, please modify the caption accordingly.
Furthermore, if this is so, other comments can be made about this figure, to highlight the differences found between the two decades. For example, in western China, cities show higher LCR for the more recent decade than in the previous decade, thus suggesting that the urban expansion in these areas of China happened mostly in the first decade of the current century.
Lines 262-264: the sentence is not very clear. Please rewrite.
Figure 7, legends of pictures c and d contain some typos that need to be corrected
Lines 338-339: please clarify what "the restrictions of the household registration system" are
Line 373: "duo" should be "due". However, the sentence seems to contain a syntax error
Line 376: Please explain what "the compensation policy for cultivated land" is
Line 526: "agree" shoulb be "agreed"

Author Response

Dear Reviewers,

Thank you for your letter and comments concerning our manuscript entitled "Using Earth Observation for Monitoring SDG 11.3.1- Ratio of Land Consumption Rate to Population Growth Rate in mainland China" (remotesensing-680275).

The comments were valuable for improving our manuscript and guiding our research. We have studied the comments carefully and have made revisions accordingly. We hope that the revisions meet with your approval and please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

I thank the authors for addressing my comments. I believe that the manuscript is very much improved.

However, there are few points that I still think require minor revisions, as follows:

Response 5

New comment: The authors need to specify more which EO data have been used. Land use data and night-time light data are the data types, but it would be much more informative if they stated which land use data and night-time light data were used. From which satellite? e.g. SNPP VIIRS?

Response 6

New comment: Consequently, the authors should be more specific in the keywords. For example, if they have used SNPP VIIRS night-time light data, the keyword should be SNPP VIIRS night-time light data

Response 17

New comment: I thank the authors to have tried to address my comment. However, I still find difficult to understand the calibration process. I suggest to rewrite the whole paragraph.

Response 18

New comment: The authors have addressed my comment. However, the meaning of the sentence at lines 201-202, i.e. "However, definitions in SDG 11.3.1 metadata emphasized to conceptual descriptions", is not so clear.

Response 25

New comment: I cannot find reference 33 by searching it on internet. The authors should provide a link to this reference.

Response 27

New comment: I understand the authors' point. I suggest them to add their reply in the text (i.e. "The LCR value is not statistically significant and we can’t say that it is a growing trend. The LCR value is low because LCR represents the annual rate at which cities uptake land for urbanized uses and our measurement period is 10 years").

Author Response

Dear Reviewers,

Thank you for your letter and comments concerning our manuscript entitled "Using Earth Observation for Monitoring SDG 11.3.1- Ratio of Land Consumption Rate to Population Growth Rate in mainland China" (remotesensing-680275).

The comments were valuable for improving our manuscript and guiding our research. We have studied the comments carefully and have made revisions accordingly. We hope that the revisions meet with your approval and please see the attachment.

Author Response File: Author Response.docx

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.