The Use of Socio-Environmental Indicators to Assess the Needs Relating to the Development of Urban Greenery

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript is devoted to the issue of assessing the greenness of urban areas using the city of Lodz (Poland) as an example. The topic of the study is relevant and is studied by many authors around the world. For this assessment, the authors use well-known methods of remote sensing of the Earth, as well as data obtained during laser scanning. The original idea of ​​the authors' study is that the authors propose to transform the basic NDVI index into new indices taking into account the height of the tree stand. This height, according to the authors, affects the volume of green mass, and accordingly, the "quality" (volume of green mass) of greening. In addition, the authors propose to take into account the spatial distribution of the local population in order to assess the "social" provision of urban greening.

Despite the relevance of the research topic, it is worth noting the list of shortcomings, as well as providing comments and recommendations:

1. There are catastrophically few modern sources for the last 5 years (2020-2024) (only 8 out of 67). There are few articles published in world-class journals among the sources. The authors did not review thematic publications published in the journal Sustainability, which may indirectly indicate that the research topic does not fit the scope of the journal.

 2. The subject of the manuscript states "to aid spatial planning". However, the authors do not pay attention to the issue of using the results of greenery assessment in spatial planning, they simply state the fact of such a possibility. I recommend adjusting the subject of the manuscript.

 3. It is recommended to review the keywords, especially «formula».

 4. The abstract does not reflect the relevance of the topic. The authors write: "Unfortunately, there are currently no proposals in the scientific literature that would allow us to uniformly determine the amount of greenery resources in different cities." However, there are many studies related to the assessment of greenery in various aspects. And in their study, the authors did not study the existing modern world experience on the research topic. A radical revision of the scientific review in the Introduction section is necessary.

The scientific review also has a poor structure. The authors first write about the provision of the population with greenery, then about the methods for determining the size of green areas, and then about the inventory. Such inconsistency and illogicality of presentation leads to a misunderstanding of the specific problem that is being studied by the authors. At the same time, the goal of the study is formulated very generally and also does not reflect the specific result that the authors want to come to.

 5. The authors speak (line 19) about the new proposed method, but do not verify it, compare it with analogs, check its correctness and adequacy. The fact is that the NDVI index is appropriate to use in the dynamics of different time intervals. Its one-time value in certain cases can lead to incorrect interpretation. The same applies to the indices proposed by the authors.

 6. Line 43 says: "Nowadays, it is futile to look for standardization in assessing the degree of greenness of cities within one country, let alone comparisons of cities in different countries." I cannot agree with this, since there are generally recognized standards (in a recommendatory format). For example, the "3-30-300" concept, the World Health Organization standards (maximum parameters for the provision of green space per capita). In addition, I strongly recommend that the authors familiarize themselves with the global concept of Green Infrastructure.

 7. The Introduction contains text that is to the Materials and Methods section (for example, from line 109). The structure of these sections needs to be optimized.

 8. The numbering of the bibliography does not correspond to the references in the text. This must be checked.

 9. The authors use different terms: sometimes «green zone», sometimes «green infrastructure», sometimes «green resources». Such mixing of terms can lead to misunderstanding of the substantive aspects.

 10. What is the rationale for using Landsat 8 (line 216)? The resolution of 30x30 images is worse than that of Santinel (10x10).

 11. Line 222: "The materials for the study area are up to date in 2011". Is it possible to use such old materials? Doesn't this affect the results of the study? After all, landscaping is a dynamic object.

 12. Item 3 Indices refers to the Materials and Methods section.

 13. What is the basis for formulas (3) and (4)? They contain the elements of scientific novelty of the research, which must be substantiated, proven and described in detail. The simplification of formulas (3) and (4) to formula (5) is unclear.

 14. How does GIi work if it is not trees that are being assessed, but shrubs, flower beds or lawns? In urban areas there are few areas with only woody vegetation. On the contrary, a large area is occupied by other types of greenery, for which it is unclear how to determine Hi and Hb (Fig. 6).

Also in line 411, the Hi and Hb values ​​are defined for trees (apparently on average). But, for example, coniferous and deciduous trees differ dramatically in height, trunk structure, and crown density, and therefore in the absorption/reflective properties of the crown. Was this aspect taken into account somehow?

In addition, there are doubts about the appropriateness of calculating GIi. In essence, this is NDVI modified to take into account the height. However, does a taller tree really mean a higher “quality” (biomass volume) of greenery?

 15. Line 453: What do the authors mean by «basic field»? Is it possible to use the proposed indices when comparing the greenness of different cities?

 16. Line 541: What is the rationale for increasing the square size to 90x90? Why not 100x100 or 200x200, etc.?

 17. In Fig. 8 it is noted that there is a “dependence of NDVI on the average height of greenery in basic fields”. However, the authors do not prove that this dependence exists. What dependence? What is the equation of the relationship? What is the tightness of the relationship?

18. Line 591-592: A distance of 500 meters does not correspond to a 10-15 minute walk for a person.

19. Line 609: An interpretation of the result must be given. What do the results obtained mean?

 20. For Fig. 15 there is no reference in the text, and there are no comments on the content of the figure.

 21. In the Conclusions section, the figures are numbered incorrectly.

 22. Line 644: "the method does not require specialized equipment or large computing units." Doesn't laser scanning require specialized equipment and material costs?

 23. Since the manuscript does not include a Discussion section, it is necessary to substantively expand the Conclusions section: to indicate the practical significance and scientific novelty of the research results, add an interpretation of all results (the results must be critically assessed), as well as possible limitations of the author's methodology, a comparison of the results with similar studies and an explanation of how the approach proposed by the authors is better than analogues. Possible ways of applying the results should also be detailed.

Comments for author File: Comments.pdf

Author Response

Comments 1: There are catastrophically few modern sources for the last 5 years (2020-2024) (only 8 out of 67). There are few articles published in world-class journals among the sources. The authors did not review thematic publications published in the journal Sustainability, which may indirectly indicate that the research topic does not fit the scope of the journal.

Response 1: Thank you for that comment. New literature review has been made. As a result we got 5 new positions in the bibliography which have been published in last 4 years.

Comments 2: The subject of the manuscript states "to aid spatial planning". However, the authors do not pay attention to the issue of using the results of greenery assessment in spatial planning, they simply state the fact of such a possibility. I recommend adjusting the subject of the manuscript.

Response 2: Thank you for that remark. The subject has been adjusted to emphasize more that the indicators just have such possibility to support spatial planning.

Comments 3: It is recommended to review the keywords, especially «formula».

Response 3: The keywords has been reviewed and changed.

Comments 4: The abstract does not reflect the relevance of the topic. The authors write: "Unfortunately, there are currently no proposals in the scientific literature that would allow us to uniformly determine the amount of greenery resources in different cities." However, there are many studies related to the assessment of greenery in various aspects. And in their study, the authors did not study the existing modern world experience on the research topic. A radical revision of the scientific review in the Introduction section is necessary.

The scientific review also has a poor structure. The authors first write about the provision of the population with greenery, then about the methods for determining the size of green areas, and then about the inventory. Such inconsistency and illogicality of presentation leads to a misunderstanding of the specific problem that is being studied by the authors. At the same time, the goal of the study is formulated very generally and also does not reflect the specific result that the authors want to come to.

Response 4: Thank you for that comment. We totally accept the fact, that at the first gimpse it might look confusing. The fact is that this strategy has been  very thoroughly thought out.

The whole principle was based on showing the "quality of life" in a given place based on the urban greenery there. And since we did not find any universal methods in the literature that would numerically describe the greenery resources in a given place, we created our own method.

Comments 5: The authors speak (line 19) about the new proposed method, but do not verify it, compare it with analogs, check its correctness and adequacy. The fact is that the NDVI index is appropriate to use in the dynamics of different time intervals. Its one-time value in certain cases can lead to incorrect interpretation. The same applies to the indices proposed by the authors.

Response 5: One of the aim was also to compare/monitor the development/changes in the greenery area in the same city in some period. We are aware of some disadvantages of the NDVI index but we wanted to make this method as easy to implement as possible.

The method has a strict mathematical basis, is based on NDVI layers verified in other studies and population density developed according to reliable data and methodology. We chose a satellite image from the beginning of the July - the period when greenery is most developed.

Comments 6: Line 43 says: "Nowadays, it is futile to look for standardization in assessing the degree of greenness of cities within one country, let alone comparisons of cities in different countries." I cannot agree with this, since there are generally recognized standards (in a recommendatory format). For example, the "3-30-300" concept, the World Health Organization standards (maximum parameters for the provision of green space per capita). In addition, I strongly recommend that the authors familiarize themselves with the global concept of Green Infrastructure.

Response 6: The sentence has been rephrased. When it comes to 3-30-300 it is a worth mentioning concept however, it does not define what a green area is and what it is not. Anyways this information has also been added to the text.

When it comes to Green infrastructure I will quote part of my last article: Green Infrastructure refers to vegetation areas marked in local spatial development plans. It is often used interchangeably with the term urban forest (Kulawik et al., 2021). However, in most plans, the concept is not clearly defined. Interestingly, in plans that do have such a definition, it most often refers to the ability to absorb stormwater, while in Poland the term impermeable layer is used (Nowakowska-Blaszczyk, 1988), not landscape or nature (Grabowski, 2022). The US Environmental Protection Agency has defined the concept of green infrastructure as a set of practices aimed at controlling stormwater (EPA, 2019). In Poland, the equivalent of GI is the concept of blue-green infrastructure, which in turn refers to the concept of green infrastructure defined by the European Commission. This definition states that green infrastructure should be understood as a network of natural and semi-natural areas, designed and managed in such a way as to provide the widest possible spectrum of ecosystem services. There is also information that blue-green infrastructure can only be located in urban or rural areas, and therefore does not apply to areas outside the boundaries of cities and villages (European Commission, 2013). The types of natural elements included in blue-green infrastructure were listed, namely: forests, natural green areas, rivers, streams and other watercourses, natural retention areas, meadows, fields, pastures, coastal areas, trees and shrubs (Solarek, 2016).

Comments 7: The Introduction contains text that is to the Materials and Methods section (for example, from line 109). The structure of these sections needs to be optimized.

Response 7: Here, only the information about the materials was mentioned which has been used in another research, so it cannot be used in material and methods chapter.

Comments 8: The numbering of the bibliography does not correspond to the references in the text. This must be checked.

Response 8: Thank you for noticing that - it has been carefully revised and corrected.

Comments 9: The authors use different terms: sometimes «green zone», sometimes «green infrastructure», sometimes «green resources». Such mixing of terms can lead to misunderstanding of the substantive aspects.

Response 9: The multitude of terms was used intentionally. It results from the fact that the same areas are named differently in different repositories as well as when defining urban standards.

Comments 10: What is the rationale for using Landsat 8 (line 216)? The resolution of 30x30 images is worse than that of Santinel (10x10).

Response 10: It was decided that this size would be appropriate for calculations for cities with large area over 100 km2. Within the city limits of Lodz, 325,691 basic fields were designated, which is a demanding number to develop for a personal computer, especially considering the fact that one of the stages was the development of LiDAR data, which can also be resource-intensive

Increasing the resolution would, in our opinion, lead to unnecessary time consumption.

Comments 11: Line 222: "The materials for the study area are up to date in 2011". Is it possible to use such old materials? Doesn't this affect the results of the study? After all, landscaping is a dynamic object.

Response 11: The data is, indeed, from older years, but our goal was not to describe the current state of the environment, but to develop and present a method in the article.. Whats more: at the time of creation of the method these were the latest publicly available LiDAR data.

Comments 12: Item 3 Indices refers to the Materials and Methods section.

Response 12: The index chapters are mostly original solutions which, due to the nature of the research, constitute the main part of the article. Hence the decision to separate this article, which in consequence resulted in better readability of the work (Materials and methods take up 6 pages, while Indexes 7 pages, after combining we would get as many as 13 pages, which would also affect the entire structure of the article).

Comments 13: What is the basis for formulas (3) and (4)? They contain the elements of scientific novelty of the research, which must be substantiated, proven and described in detail. The simplification of formulas (3) and (4) to formula (5) is unclear.

Response 13: The simplification applies only to formula no. 4, as described in the text.

It results from the transformation of equations of the value in a common fraction.

Comments 14: How does GIi work if it is not trees that are being assessed, but shrubs, flower beds or lawns? In urban areas there are few areas with only woody vegetation. On the contrary, a large area is occupied by other types of greenery, for which it is unclear how to determine Hi and Hb (Fig. 6). Also in line 411, the Hi and Hb values are defined for trees (apparently on average). But, for example, coniferous and deciduous trees differ dramatically in height, trunk structure, and crown density, and therefore in the absorption/reflective properties of the crown. Was this aspect taken into account somehow? In addition, there are doubts about the appropriateness of calculating GIi. In essence, this is NDVI modified to take into account the height. However, does a taller tree really mean a higher “quality” (biomass volume) of greenery?

Response 14: Hb is only mentioned here to show that not all of the vegetation height performs ecological functions. However, in this case, as mentioned in point 13, this value is shortened. Formula 4 is therefore presented to better illustrate how to arrive at the final formula. And Yes, and all kind of areas has been taken into consideration.

We deliberately selected trees at intersections of roads to choose the most pessimistic option (high crown base). In practice, it may be lower and the GI value may therefore be higher. Since we were unable to measure all trees, we decided to use a method that indicates the "minimum" version.

And regarding the addition: Thank you - you are absolutely right. But that's why we tried to estimate where the NDVI saturation point is located. It is proved that NDVI will not reflect the real biomass volume if the thickness is too big. Since we calculated this value = 1m then we decided that above 1 m NDVI will have more or less the same value, no matter how high the vegetation is.

Comments 15: Line 453: What do the authors mean by «basic field»? Is it possible to use the proposed indices when comparing the greenness of different cities?

Response 15: Basic fields in our case was a pixel from Landsat Image. It is up to the user what will be a basic field in his/her case, but then the user needs to be able to calculate all ingredients (NDVI and VHM) for the same 'basic fields'.

Comments 16: Line 541: What is the rationale for increasing the square size to 90x90? Why not 100x100 or 200x200, etc.?

Response 16: Since we had image of 30x30m resolution we were no able to create any other square size but the multiplication of the basic fields.

Comments 17: In Fig. 8 it is noted that there is a “dependence of NDVI on the average height of greenery in basic fields”. However, the authors do not prove that this dependence exists. What dependence? What is the equation of the relationship? What is the tightness of the relationship?

Response 17: Thank you very much for this comment. We really cannot speak of a relationship because we do not have sufficient statistical evidence for it. The description has therefore been changed accordingly.

Comments 18: Line 591-592: A distance of 500 meters does not correspond to a 10-15 minute walk for a person.

Response 18: I can agree, but we were based on some literature. E.g. Google maps shows the average pace of walking is 15minutes / 1km. I believe it referred to leisurely walking rather than walking for communication purposes.

Comments 19: Line 609: An interpretation of the result must be given. What do the results obtained mean?

Response 19: Thank you for this very important remark. An interpretation of the results has been provided as suggested.

Comments 20: For Fig. 15 there is no reference in the text, and there are no comments on the content of the figure.

Response 20: A specific comment has been added to the text.

Comments 21: In the Conclusions section, the figures are numbered incorrectly.

Response 21: Figures presented in the Conclusions section were already used before in the same article. I has been provided second time to have a better overview of the result, by comparing two different maps. It is more the reference to the figures than actual new figures.

Comments 22: Line 644: "the method does not require specialized equipment or large computing units." Doesn't laser scanning require specialized equipment and material costs?

Response 22: Not here, since the aim for this methodology was to use a public data - not to scan by themselves.

Comments 23: Since the manuscript does not include a Discussion section, it is necessary to substantively expand the Conclusions section: to indicate the practical significance and scientific novelty of the research results, add an interpretation of all results (the results must be critically assessed), as well as possible limitations of the author's methodology, a comparison of the results with similar studies and an explanation of how the approach proposed by the authors is better than analogues. Possible ways of applying the results should also be detailed.

Response 23: Additional paragraph with such information has been added to the text.

Reviewer 2 Report

Comments and Suggestions for Authors

This paper presents a valuable contribution to urban planning and remote sensing by developing new indices to assess urban greenery. But there are some areas could be improved:

 

Abstract: The abstract is informative but can be improved by emphasizing the paper's contribution and novelty more clearly. It introduces the problem well but should briefly summarize the methods and results. Additionally, the abstract could be more concise and avoid repetition. For instance, the point about the importance of vegetation in urban areas is reiterated, which could be streamlined.

 

IntroductIon: The introduction could benefit from a more focused discussion of the knowledge gap the study aims to fill. The literature review is extensive but somewhat general. It could be improved by emphasizing how this study's approach is different or more advanced than previous studies. The last paragraph should clearly state the research objectives and what the reader should expect from the paper.

 

Methodology: The choice of spatial resolution (30m × 30m) is justified, but more discussion on the potential limitations or trade-offs of this resolution would be helpful. How does it impact the accuracy of greenery assessment in densely urbanized areas?

 

 

Results and discussion: The discussion should better link the findings to broader implications for urban planning. For example, what specific policies could benefit from the application of these greenery indices?

The discussion could be compared more explicitly with other studies or methods used in different cities or countries. This would help demonstrate the study's relevance beyond the specific case of Lodz.

 

Conclusion: The conclusion could be more concise and should focus on the study’s key contributions. Some points in the conclusion seem more suitable for the discussion section, such as the detailed comparison between public data and the study’s findings.

A brief mention of potential future research or limitations would strengthen the conclusion. For instance, what are the next steps in improving the indices or extending the research to other cities?

Reference: Some references are relatively old (e.g., from the 1970s and 1980s). It may be beneficial to ensure the literature review is up-to-date by including more recent studies from the past five years, especially on advancements in remote sensing and urban planning.

 

Comments on the Quality of English Language

The manuscript contains some grammatical issues and awkward phrasing, which can disrupt the flow. For example, some sentences in the methodology section are overly complex and could be simplified for clarity.

There are also some minor typographical errors (e.g., "sat" instead of "saturation" in formula explanations). A thorough proofreading or language editing pass is recommended to improve readability.

Author Response

Comments 1: Abstract: The abstract is informative but can be improved by emphasizing the paper's contribution and novelty more clearly. It introduces the problem well but should briefly summarize the methods and results. Additionally, the abstract could be more concise and avoid repetition. For instance, the point about the importance of vegetation in urban areas is reiterated, which could be streamlined.

Response 1: Thank you for that remark. An abstract has been supplied with proposed information.

Comments 2: Introduction: The introduction could benefit from a more focused discussion of the knowledge gap the study aims to fill. The literature review is extensive but somewhat general. It could be improved by emphasizing how this study's approach is different or more advanced than previous studies. The last paragraph should clearly state the research objectives and what the reader should expect from the paper.

Response 2: Thank you for that comment. New literature review has been made. As a result we got 5 new positions in the bibliography which have been published in last 4 years.

Comments 3: Methodology: The choice of spatial resolution (30m × 30m) is justified, but more discussion on the potential limitations or trade-offs of this resolution would be helpful. How does it impact the accuracy of greenery assessment in densely urbanized areas?

Response 3: We agree with that opinion. We decided to add such information in the Conclusions section.

Comments 4: Results and discussion: The discussion should better link the findings to broader implications for urban planning. For example, what specific policies could benefit from the application of these greenery indices? The discussion could be compared more explicitly with other studies or methods used in different cities or countries. This would help demonstrate the study's relevance beyond the specific case of Lodz.

Response 4: It has been added to the conclusions section.

Comments 5: Conclusion: The conclusion could be more concise and should focus on the study’s key contributions. Some points in the conclusion seem more suitable for the discussion section, such as the detailed comparison between public data and the study’s findings. A brief mention of potential future research or limitations would strengthen the conclusion. For instance, what are the next steps in improving the indices or extending the research to other cities?

Response 5: A specific information has been added to the Conclusion section.

Comments 6: Reference: Some references are relatively old (e.g., from the 1970s and 1980s). It may be beneficial to ensure the literature review is up-to-date by including more recent studies from the past five years, especially on advancements in remote sensing and urban planning.

Response 6: New literature review has been made. As a result we got 5 new positions in the bibliography which have been published in last 4 years.

Comments 7: The manuscript contains some grammatical issues and awkward phrasing, which can disrupt the flow. For example, some sentences in the methodology section are overly complex and could be simplified for clarity. There are also some minor typographical errors (e.g., "sat" instead of "saturation" in formula explanations). A thorough proofreading or language editing pass is recommended to improve readability.

Response 7: The text has been reviewed by the translator.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Comments are in the file

Comments for author File: Comments.pdf

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

After careful revisions by the authors, the paper has met the requirements for publication in this journal.

Author Response

Thank you for your review and accepting the article for publishing.

It was very helpful to follow your tips and comments.

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

no comments