From Expansion to Shrinkage: An Assessment of the Carbon Effect from Spatial Reconfiguration of Rural Human Settlements in the Wuhan Metropolitan Area

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This case study of land use change in rural areas of the Wuhan Metro Area brings together useful data and models, but the analysis needs further refinement and the English usage needs major improvements to ensure that the findings are clear for an international audience.  I have made some suggestions for improvements below for your consideration.

l. 117  “rural built-up land, which refers to rural settlements independent of towns and cities.”  This needs to be discussed in much more depth:  how are towns and cities defined in the study — are you using administrative boundaries or are you classifying towns vs. rural based on the original land use classifications?  do the boundaries of towns and cities change over the 1995-2020 study period?  how do the definitions affect your analysis that shows pixels moving between rural built-up and urban built-up land (red color in Figure 4a)

l. 178 “the quantity of rural built-up land in 2010 decreased” (better English: “decreased in 2010”).  The decrease from 2005 is very small (looks like about 1% in Figure 3) so it would be good to confirm that this finding is not just an artifact of changing urban/rural boundaries or definitions.  If it is a valid finding, connect this discussion to the finding on line 213 about the rates of land transferred (that section is not clear: transfer from what to what? rural built-up land to other rural uses?  or does it include rural built-up land transferred to urban built-up land?)

l. 195 “in the main city of Wuhan, there is an obvious hollow area.”  Surely this is because there is no rural land in that area that could possibly be the site of rural built-up expansion or shrinkage.  I suggest you shade 2020 urban build-out land separately in Figure 4 (an and b) to indicate that is not part of your analysis.

l. 291 “water became the primary source” — in other words, wetlands, rivers, and lakes were filled in order to expand rural built-up land.  Discuss the ecosystem services lost by filling wetlands (including carbon storage but also flood protection, water supply, etc.)  However, if those same lands reverted to water in the subsequent time period, it may be that temporarily dry reservoirs and wetlands were incorrectly classified as rural built-up land, as can happen in drought periods.

l. 347 The most interesting part of the paper for me is the tension between land use plans and farmers’ choices about land use.  The city government appears to be trying to consolidate villages to expand and preserve farmland, but in some places farmers continue to build up.  This tension (and its impacts on carbon storage) could be the main point of the paper and would be very interesting for an international audience.

l. 358 Table 9 and related discussion:  2030 is only a few years away.  You have 25 years of data here, so why not make your model projections further into the future — at least to 2040 if not 2055?

l. 403 Figure 7.  The caption says (unit: t) but is that tons per pixel?  tons per km2?

l.419 Nighttime lighting is obviously an effect, not a cause (or driver), of rural built-up land expansion.  Rephrase this discussion (and Figure 8) to show that these are correlations or associations, not necessarily causes.

l. 434 Section 4.2, Policy Implications: add an introductory sentence or two to this section to explain that you are making three main proposals based on your findings.  The grammatical structure of the three paragraphs needs work for clarity and consistency.  (The suggestions themselves are not bad, but should be more closely linked to your specific findings.)

 

Comments on the Quality of English Language

Please work with an editor or native English speaker to correct the usage and grammar throughout the paper.  There are numerous cases of misused commas and overly long sentences that detract from the reader’s understanding.

Author Response

This case study of land use change in rural areas of the Wuhan Metro Area brings together useful data and models, but the analysis needs further refinement and the English usage needs major improvements to ensure that the findings are clear for an international audience. I have made some suggestions for improvements below for your consideration.

 

1）117 “rural built-up land, which refers to rural settlements independent of towns and cities.” This needs to be discussed in much more depth: how are towns and cities defined in the study — are you using administrative boundaries or are you classifying towns vs. rural based on the original land use classifications? do the boundaries of towns and cities change over the 1995-2020 study period? how do the definitions affect your analysis that shows pixels moving between rural built-up and urban built-up land (red color in Figure 4a)

Response: Thank you very much for your comments. We classify urban and rural built-up land according to the land use classification. The details of how to categorize have been explained in detail in the paper.

 

2.2.1. Urban built-up land and rural built-up land classification system

The rural settlement data used in this study were obtained from the Resource and Environmental Science Data Center of the Chinese Academy of Sciences (http://www.resdc.cn). The data covered six primary types and 25 secondary types of arable land, forest land, grassland, watershed, built-up land and unutilized land. Based on Landsat series data, the integrated valuation accuracy of the secondary land use types is >90% [30]. In this study, we refer to Wang et al. [31], to categorize and merge the three secondary land classes within the primary land class of construction land. Specifically, “urban land” and “other built-up land” are combined as urban built-up land, and “rural settlements” are regarded as rural built-up land. Detailed descriptions of each land use type are given in Table 1 [32].

Table 1. Urban built-up land and rural settlement land classification system.

Classification of built-up land	Subclasses	Description
Urban built-up land	Urban land	Land in large, medium and small cities and built-up areas above the county town level.
	Other built-up land	Factories, mines, large industrial areas, oilfields, saltworks, quarries, as well as transportation roads and airports.
Rural built-up land	Rural settlements	The built-up areas in rural settlements

Please see these words in lines 113-124.

 

• 178 “the quantity of rural built-up land in 2010 decreased” (better English: “decreased in 2010”). The decrease from 2005 is very small (looks like about 1% in Figure 3) so it would be good to confirm that this finding is not just an artifact of changing urban/rural boundaries or definitions. If it is a valid finding, connect this discussion to the finding on line 213 about the rates of land transferred (that section is not clear: transfer from what to what? rural built-up land to other rural uses? or does it include rural built-up land transferred to urban built-up land?)

Response:Thank you for your suggestions. 

①The data we used came from the data of the Resource and Environmental Science Data Center of the Chinese Academy of Sciences (http://www.resdc.cn). The data on rural construction land provided by this center are clearly classified and of accurate quality, with high accuracy of secondary classification (Ning et al, 2018). The data inherently take into account the adjustment of administrative divisions and have a good degree of currency and accuracy.

①We have amended it to “decreduced in 2010”. The full text has also been revised. Please see these words in line 234, line 308, line 322, line 404 and line 464.

②We have added an explanation of land flow. During this period, rural built-up land was mainly transferred to arable land and urban built-up land, with a transfer area of 8,702ha and 4,026ha respectively. Moreover, most of the new rural built-up land originated from arable land, amounting to 12,029ha, showing a two-way dynamic between arable land and rural built-up land. However, the conversion of rural built-up land to urban built-up land is a one-way process. In general, the area of land compensation is not sufficient to balance the outflow of rural construction land.

Please see these words in lines 235-241.

 

• 195 “in the main city of Wuhan, there is an obvious hollow area.” Surely this is because there is no rural land in that area that could possibly be the site of rural built-up expansion or shrinkage. I suggest you shade 2020 urban build-out land separately in Figure 4 (a and b) to indicate that is not part of your analysis.

Response:Thank you for your suggestions. We have marked the 2020 urban built-up area separately in gray. In fact, the area of rural built-up areas has changed relatively little and is very inconspicuous in the map. To visualize this, in the previous draft we set the outline color of each parcel that changed to the same color as well. It may result in a visualization of a high amount of change that is not consistent with the facts. For accurate representation, we eliminated the outer contour color of the rural built-up land parcels.

 

Figure 4. Changes in rural built-up land in the Wuhan Metropolitan Area, 1995-2020. (a) represents the spatial distribution of the expansion of rural built-up land; (b) represents the spatial distribution of the shrinkage of rural built-up land.

Please see these words in lines 262-265.

 

• 291 “water became the primary source” — in other words, wetlands, rivers, and lakes were filled in order to expand rural built-up land. Discuss the ecosystem services lost by filling wetlands (including carbon storage but also flood protection, water supply, etc.) However, if those same lands reverted to water in the subsequent time period, it may be that temporarily dry reservoirs and wetlands were incorrectly classified as rural built-up land, as can happen in drought periods.

Response:Thank you for your suggestions. We added additional discussion of the ecosystem services lost by filling wetlands.

①With the expansion of rural built-up land, wetlands, rivers and lakes are often filled in, resulting in the impairment of key ecosystem services. Wetlands absorb carbon dioxide, regulate climate and provide flood control. As an important freshwater resource, wetlands are critical to the regional water cycle and water supply. Landfilling of wetlands for the construction of rural settlements not only weakens natural barriers, but may also exacerbate the risk of extreme weather and water scarcity, posing a long-term threat to ecological balance and human well-being. Please see these words in lines 357-363.

②We believe that temporarily dry reservoirs and wetlands are not misclassified as rural built-up land for the following reasons: Firstly The land use data used are from the Landsat series, which have an accuracy of >90% for the combined valuation of secondary land use types (Ning et al, 2018). Secondly, as you point out, if some areas were indeed misclassified, then a large number of conversions to waters should have been observed between 2000 and 2005. However, according to the data in Table 4, only 191 hectares of rural built-up land were converted to watersheds during this time period. Therefore, we believe that these areas are not incorrectly classified.

 

• 347 The most interesting part of the paper for me is the tension between land use plans and farmers’ choices about land use. The city government appears to be trying to consolidate villages to expand and preserve farmland, but in some places farmers continue to build up. This tension (and its impacts on carbon storage) could be the main point of the paper and would be very interesting for an international audience.

Response: Thank you. After your instruction, we realized that this was the point of the article and added the discussion here.

This study further provides a comparative analysis of a specific land parcel within the Wuhan City Circle under different scenarios (Figure 8). According to the Q2 and Q3 simulation results, the dynamic changes in rural built-up land do not occur randomly, but follow a certain spatial pattern. From a macroscopic perspective, the expansion of rural construction land shows a tendency to agglomerate on a large scale. Because of the concentration of economic activities and better infrastructure, new built-up land tends to expand around existing built-up areas, forming a continuous zone of built-up land. From a micro perspective, different villages or townships are often affected by topography, land ownership distribution, and rural road layout. Farmers will carry out land development on their own according to their actual needs and land location. In short, most of the dynamic changes have occurred around the original homesteads, forming a tendency of clustering in a large area and dispersing in a small area. At present, there is a mismatch between the ideal goals of land use planning and the real needs of farmers' individual land use choices. On the one hand, planners hope to achieve intensive use of land resources and ecological protection by merging villages and optimizing the layout. On the other hand, farmers make land-use choices based on their own life and livelihood needs that are in line with their own interests. This contradiction not only leads to a significant reduction in the implementation of land use planning, but also may have a negative impact on regional carbon stocks.

 

Figure 8. Changes in the spatial pattern of rural built-up land in Wuhan Metropolitan Area. (a) represents a natural development scenario; (b)represents a scenario of rural built-up land shrinkage ; (c) represents a scenario of rural built-up land expansion.

Please see these words in lines 413-435.

 

• 358 Table 9 and related discussion: 2030 is only a few years away. You have 25 years of data here, so why not make your model projections further into the future — at least to 2040 if not 2055?

Response: Thank you. We use the probability of land transfer from 2010-2020 to project to 2030, which would be more accurate. During the 25-year period from 1995-2020, China has experienced rapid development and is in an important period of reform and opening up. In the future stage of development, China will face new policies, changes in economic models, and other human or natural factors. The impact of these new variables on land use change may not be accurately captured by earlier data. Therefore, using data from an earlier period to predict the situation in 2040 or 2055 may lead to a decrease in the credibility of the prediction results, which in turn affects the effectiveness of decision-making.

 

• 403 Figure 7. The caption says (unit: t) but is that tons per pixel? tons per km2?

Response: Thank you for your careful reading. We apologize for our vague statements. The unit is t/ha.

Please see these words in line 483.

 

• 419 Nighttime lighting is obviously an effect, not a cause (or driver), of rural built-up land expansion. Rephrase this discussion (and Figure 8) to show that these are correlations or associations, not necessarily causes.

Response: Thank you. We replaced this section with an analysis of relevant factors and rephrased the discussion. In addition, we replaced Figure 8 with Table 11.

The contribution of the relevant factors of the changes in different land use types was obtained in PLUS model (Figure 10). Although there are differences in the degree of influence, the top three most relevant factors for changes in major ecological land uses are temperature, precipitation and population density. Firstly, temperature directly affects the growing conditions of plants in ecosystems as well as the ecological structure of water, which in turn leads to the persistence of woodland cover and changes in aquatic habitats. Secondly, the amount and distribution of precipitation has a profound impact effect on all types of ecological land use by influencing agricultural irrigation, the frequency of woodland fires, and the health of grassland. Thirdly, population density is also closely related to changes in land use in built-up areas of cities, with a contribution of 0.2327, much higher than other factors. As the population concentrates, the demand for housing, commercial space, industrial areas and public service facilities increases, thus pushing the city to expand to the periphery or reorganize its internal space.

The top three relevant factors for change in rural built-up land are nighttime lighting, precipitation, and population density. The least contributing correlates are slope orientation, distance to secondary roads, and distance to feeder roads. Areas with more intense nighttime lighting tend to have a higher concentration of human activity, resulting in a greater demand for building land. In addition, transportation accessibility has the least relevance to land use change of all the factors involved. Improvements in transportation infrastructure are often a response to land development activities that have already taken place or are expected to grow, and their correlation with land use change may take a longer period to become apparent.

Table 11. Contribution of factors related to changes in different land use types.

Factors	Cropland	Woodland	Grassland	Water	Urban built-up land	Rural built-up land	Unused land
Distance to secondary road	0.036	0.026	0.027	0.033	0.035	0.033	0.027
Elevation	0.058	0.066	0.169	0.074	0.112	0.100	0.035
Distance to highway	0.067	0.049	0.035	0.049	0.054	0.054	0.033
GDP	0.104	0.087	0.103	0.109	0.073	0.075	0.070
Precipitation	0.129	0.143	0.150	0.115	0.064	0.127	0.080
slope	0.041	0.036	0.036	0.041	0.081	0.068	0.231
Population	0.116	0.144	0.152	0.151	0.233	0.124	0.031
Slope orientation	0.029	0.035	0.034	0.032	0.027	0.039	0.022
Temperature	0.137	0.161	0.122	0.144	0.067	0.076	0.201
Distance to railway	0.065	0.051	0.046	0.057	0.093	0.057	0.029
Soil type	0.033	0.034	0.023	0.038	0.022	0.043	0.063
Nighttime Lighting	0.115	0.096	0.063	0.101	0.096	0.138	0.107
Distance to branch road	0.032	0.033	0.025	0.026	0.019	0.026	0.020
Distance to the main road	0.038	0.041	0.016	0.033	0.026	0.041	0.049

Please see these words in lines 487-510.

 

• 434 Section 4.2, Policy Implications: add an introductory sentence or two to this section to explain that you are making three main proposals based on your findings. The grammatical structure of the three paragraphs needs work for clarity and consistency. (The suggestions themselves are not bad, but should be more closely linked to your specific findings.)

Response: Thank you very much for your suggestions.

①We have added introductory sentences before the policy implications.

Based on the findings of this study, several policy implications are drawn to guide future land management and planning practices in the Wuhan Metropolitan Area, as well as serve as a reference for other regions undergoing similar transformations. Please see these words in lines 537-539.

②We have refined the three main recommendations, each of which now corresponds to a conclusion.

(1) In response to the ongoing increase of rural constructed land and its influence on ecosystem carbon storage, the government should improve rural built land transfer management, optimize the transfer mechanism, and encourage reasonable transfers to avoid land idleness and waste. Simultaneously, it should ramp up ecological restoration activities in critical places such as the Wu-E border, Tianmen, and southern Xiantao to improve regional carbon storage capacity and encourage ecosystem carbon stock recovery and expansion.

(2) The government should promote a shift in land-use planning to a “demand-oriented” approach. The actual needs and interests of farmers should be fully considered and respected in the planning process to ensure that planning programs are closely integrated with the production and life of farmers. By enhancing the flexibility and operability of planning, the planning objectives will be closer to the actual situation of farmers, thus improving the implementation of planning and acceptance by farmers, and reducing the negative impacts on regional carbon stocks.

(3) In order to strengthen the management of carbon stock in land resources, the government should establish a carbon stock monitoring system to regularly assess and report on the changes in carbon stock. At the same time, it should implement differentiated carbon stock protection policies based on the geographical distribution characteristics of carbon stock changes, and give more support to regions with faster carbon stock growth to promote balanced regional development. Through policy guidance and market mechanisms, rational flow and optimal allocation of factors of production within the region should be promoted, so as to realize the harmonious unity of economic, social and ecological benefits. 

Please see these words in lines 540-562.

 

• Please work with an editor or native English speaker to correct the usage and grammar throughout the pap There are numerous cases of misused commas and overly long sentences that detract from the reader’s understanding.

Response: Thanks for your suggestion. We feel sorry for our poor writings, however, we do invite a friend of us who is a native English speaker from the USA to help polish our article. And we hope the revised manuscript could be acceptable for you.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript analyses land use changes between years 1995-2020 in the Wuhan Metropolitan Area with a special focus on rural built-up areas. It applies Invest model to assess changes in Carbon storage and Plus model to foresee land use changes under three scenarios and their implication for future Carbon storage.

In general I am fine with the concept and overall workflow. My concern is about focusing to “rural built-up areas”. It is not clearly defined what authors consider “rural built-up areas” or how were they distinguished from “urban built-up areas”. Are they defined by belonging to some administrative area or were they delineated by some physical structural characteristics? In addition,  in Invest model both rural and urban built-up areas applied identical C values (Table 2), there is no point in distinguishing them since the resulting C storage values are not different in rural or urban built-up areas if they change one into another.

Moreover, I have serious doubts about presented types of land use change. I do not see it very likely that rural built-up areas change into ALL other land use types (built-up into cropland, Table 4 shrinking) or vice-versa (urban built-up into rural built-up areas ,Table 5 Expansion). These changes are far too numerous in Figure 4 to be believable. Urbanisation is usually one directional land use change, it is hard to believe that it is so both ways dynamic in the study area. This is supported by Figure 3, where total rural built-up areas increase with time. Observed changes could be a result of spatial error in input data sources when a 30 m pixel is interpreted as built-up and later as cropland or grassland (but it is due to spatial bias in pixels not due to real change in land use).

There is a need to better explain the 3 scenarios, what are their driving forces and why is decrease/increase set to 40% (Table 3). In addition, the conversion from built-up into other land uses is very unlikely in normal conditions (removal of infrastructure and restoration of fertile soil production).

Summing up, I do not see any added value in focusing on "rural built-up area” unless they are sufficiently justified and clearly described how they differ from urban built-up areas – certainly no in Carbon storage as they use the identical C value. In case the manuscript is edited accordingly to reviews it will require adjustment in its title, too.

Minor technical remarks:

Consider English usage of terms such as “encroached”, “ecological migration”, “withdrawing villages”…

There is no clearly defined aim of the article, lines 86-92.

No need to explain the manuscript structure, lines 93-98.

Line 158 – LEAS or LESA model?

Table 4 and 5 – Please mark land use changes as” Rural built-up land – into – Cropland”, and so on…

Figures 6  and 7 are too small to be readable.

Author Response

Dear reviewer:

We appreciate the time and effort you put into reviewing the previous version of the manuscript.

Your suggestions have enabled us to improve our work. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Accordingly, we have uploaded a copy of the original manuscript with highlighting the key changes in blue.

Appended to this letter is our point-by-point response to the comments raised by the reviewers.

The comments are reproduced and our responses are given directly afterward in a different color (blue).

We would like also to thank you for allowing us to resubmit a revised copy of the manuscript.

Sincerely,

Yingxue Rao

Chenxi Wu

Qingsong He

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The article assesses the carbon impact resulting from the reconfiguration of rural human settlements in the Wuhan metropolitan area. The introduction provides a comprehensive state-of-the-art review, but it lacks specific objectives. The methodology could be better explained by reducing the fragmentation of sections and providing a clearer description of all procedures (for example, how RSR and RER are integrated into the research framework, or the implementation of the weight setting in section 2.4.2). A more detailed explanation of the methodology would help readers better understand the results. The results section is quite extensive; incorporating more graphical or tabular data could enhance clarity. The discussion would benefit from comparisons with results from other studies (using references from the state-of-the-art review).

Here are my additional comments:

Major Comments:

- Clearly enumerate the goals of the article in the introduction. What is the main objective? Be concise.

- The titles of each image and table need to be more descriptive and provide enough information to be self-explanatory.

- Explain why data from 2000 to 2010 was selected for accuracy verification in more detail.

- Enrich the discussion section by comparing it with other articles referenced in the state-of-the-art review.

Minor Comments:

- Line 54: Why is “demolition and new construction” in quotation marks? This paragraph may be specific to the study area, as this process is not generalized (for example, in many parts of rural Europe, this process involves only abandonment, not demolition and new construction).

- Line 64: Missing a period. Change “storage However,” to “storage. However,”

- Line 83: Is there any reference to the Plus model?

- Line 102: What is meant by "large"? Provide the surface area of the study area.

- Lines 135 and 140: These sections are too brief. I recommend integrating these comments into section 2.2 as a narrative rather than splitting them into separate sections.

- Equations 1 and 2: Equation 2 is incorrect and appears to be a duplicate of Equation 1.

- Line 150: What does this “、” mean? Should it be a comma?

Finally, a question to discuss:

- Could remote sensing data, such as satellite imagery, be utilized to enrich or validate this type of research?

Author Response

Dear reviewer:

We appreciate the time and effort you put into reviewing the previous version of the manuscript.

Your suggestions have enabled us to improve our work. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Accordingly, we have uploaded a copy of the original manuscript with highlighting the key changes in blue.

Appended to this letter is our point-by-point response to the comments raised by the reviewers.

The comments are reproduced and our responses are given directly afterward in a different color (blue).

We would like also to thank you for allowing us to resubmit a revised copy of the manuscript.

Sincerely,

Yingxue Rao

Chenxi Wu

Qingsong He

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for your thorough responses to my questions and suggestions.  I think the paper is much improved and will be of interest to the readers of this journal.  I recommend one minor change: For figures 4a-b, you responded that "in the previous draft we set the outline color of each parcel that changed to the same color as well. It may result in a visualization of a high amount of change that is not consistent with the facts. For accurate representation, we eliminated the outer contour color of the rural built-up land parcels." While you are technically correct, the resulting figures are no longer useful for illustrating the spatial distribution of the changed parcels.  Since the measured areas of each time of land use change is reported separately, I think it would be better to restore the outer color for the changed parcels so that we can see *where* they are located, even if that exaggerates their area on the map.  You can make a note of this effect in the figure caption to avoid misunderstanding.

 

Comments on the Quality of English Language

The English usage is improved but remains inconsistent.  I still see a capitalization error in the first paragraph and poorly translated Chinese terms in some of the new text.  Please ensure that the final version of the paper is reviewed carefully by a qualified English-language editor.

Author Response

Dear reviewer:

Thank you very much for your invaluable comments. We sincerely appreciate the time and effort you have put into reviewing our manuscript. Your feedback has been instrumental in guiding our revisions.

Attached to this letter is our detailed, point-by-point response to each comment raised by the reviewers. For clarity, the original comments are reproduced, followed by our responses in a different color (blue).

We are deeply grateful for the opportunity to resubmit a revised version of our manuscript and for your continued consideration.

Sincerely,

Yingxue Rao

Chenxi Wu

Qingsong He

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Authors replied to all my comments and edited the manuscript accordingly.

However, they did not replied to this remark:

I do not see it very likely that rural built-up areas change into ALL other land use types (built-up into cropland, Table 4 shrinking) or vice-versa (urban built-up into rural built-up areas ,Table 5 Expansion). These changes are far too numerous in Figure 4 to be believable. Urbanisation is usually one directional land use change, it is hard to believe that it is so both ways dynamic in the study area.

Without a proper expalantion or comment to this issue, the results are questionable.

In addition, Figure 4, even when edited, shows no information on land use change due to the minimal size of changed pixels. I suggest to manipulate it in order to be visible (one way would be reclassification into larger grid e.g. 10x10 km or larger keeping the major land use change as shown value or similar approach).

Author Response

Dear reviewer:

Thank you very much for your invaluable comments. We sincerely appreciate the time and effort you have put into reviewing our manuscript. Your feedback has been instrumental in guiding our revisions.

Attached to this letter is our detailed, point-by-point response to each comment raised by the reviewers. For clarity, the original comments are reproduced, followed by our responses in a different color (blue).

We are deeply grateful for the opportunity to resubmit a revised version of our manuscript and for your continued consideration.

Sincerely,

Yingxue Rao

Chenxi Wu

Qingsong He

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have addressed all my comments well, and the article has been improved accordingly. I have a few minor comments:

Minor Comments:

- Replace RSR with RER in Equation 2.

- Figure 3: What type is each scale on the x-axis? Are the bars representing area and the line representing proportion? Please include this information in the figure caption.

- Figure 4 has a legend with different colors, but the map is displayed in gray, or at least the different parts are not distinguishable at this scale.

Author Response

Dear reviewer:

Thank you very much for your invaluable comments. We sincerely appreciate the time and effort you have put into reviewing our manuscript. Your feedback has been instrumental in guiding our revisions.

Attached to this letter is our detailed, point-by-point response to each comment raised by the reviewers. For clarity, the original comments are reproduced, followed by our responses in a different color (blue).

We are deeply grateful for the opportunity to resubmit a revised version of our manuscript and for your continued consideration.

Sincerely,

Yingxue Rao

Chenxi Wu

Qingsong He

Author Response File: Author Response.docx