Connecting the Dots between Urban Morphology and the Air Quality of Cities under a Changing Climate: A Bibliometric Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Line 188-190: 574articles +605articles+…, the sum are 1479, not 1481. Check the data, please.

Table1: what are the relationships between the boldface (urban climate  635) and non-boldface text below?

Table1 title “in the 1481 articles”, I want to if there are repeated articles in each domain of statistics.

Figure4: 5 legends, three columns in modeling and monitoring. If there is no data in that period such as 1970-1980 and 1981-1990, explain or delete it.

Table3: the row in Reference [39], the second column “Shenyan, China”, the right one “Shenyang, China”.

Author Response

The authors acknowledge and appreciate the reviewer’s comments, and believe that these changes improved the manuscript. All changes are marked in the revised version of the manuscript with Track Changes. The authors would like to highlight the main changes that were made in the manuscript as result of the reviewers’ suggestions:

• The entire manuscript was revised by a native speaker to correct any grammatical errors;
• The abstract was revised to be more specific in its scope and conclusions;
• The total number of articles analysed was corrected to 1479, instead of 1481;
• Figure 4 was changed to remove two time periods where there was no data;
• A note was added to Table 3 to provide full name for the abbreviations.

 

1) Line 188-190: 574articles +605articles+…, the sum are 1479, not 1481. Check the data, please.

The authors confirmed that the total number of articles is 1479. The above-mentioned correction was made in the manuscript for all instances. 

 

2) Table1: what are the relationships between the boldface (urban climate  635) and non-boldface text below?

The boldface for Urban Climate 635 was an editing error. The above-mentioned correction was made in the manuscript. 

 

3) Table1 title “in the 1481 articles”, I want to if there are repeated articles in each domain of statistics.

The authors do not know if they correctly understand the reviewer’s question. If the reviewer is asking if there are articles addressing more than one domain, the answer is yes. As it is written in lines 207-210, “From the 1479 articles, 574 articles (38.8%) assess 1 domain, 605 articles (40.9%) assess 2 domains, 250 articles (16.9%) assess 3 domains, 41 articles (2.7%) assess 4 do-mains, 6 articles (0.4%) assess 5 domains, and 3 articles (0.2%) assess 6 domains.”

 

4) Figure4: 5 legends, three columns in modeling and monitoring. If there is no data in that period such as 1970-1980 and 1981-1990, explain or delete it.

The paragraph following Figure 4 (lines 283-289) attempts to explain why there are no results for the time period of 1970-1990 – “…in the last two decades, likely due to the rapid development of satellite-based technology [25]. Both “Modelling” and “Monitoring” tools have only begun being utilized (in the studies included in this paper) since 1991. As technology evolves and becomes more accessible, so do the different tools that are available to researchers, and both tools show an increase over time…”.

Furthermore, Figure 4 was changed to remove the time periods of 1970-1980 and 1981-1990, and the information was added to the caption: “Figure 4. Contribution (%) of the different tools, per decade of publication. The decades 1970-1980 and 1981-1990 were not included in the plot since no paper from that period uses monitoring or modelling tools.”

 

5) Table3: the row in Reference [39], the second column “Shenyan, China”, the right one “Shenyang, China”.

The above-mentioned correction was made in the manuscript

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript reports a comprehensive literature review regarding urban morphology and air quality, etc. using VOSviewer. The findings are interesting and the results presented in Figure 2 (Keyword distribution and their relation), Figure 3 (Contribution % of the different domains per decade of publication), and Figure 5 (Keyword timeline) would be interesting to the audience of the journal. To me the manuscript is acceptable provided that the following two major issues are addressed in the revised manuscript:

1.       Use of English:

A comprehensive editing of the use of language is needed. There are quite some grammatical and stylish errors throughout the manuscript, For example, the abstract.

2.       Research Gaps:

To me the software “VOSviewer” hardly identifies the research gaps or formulate the scientific questions. As such, I would suggest the authors, based on the outcome given by VOSviewer, look into the papers, and conduct a detailed, systematic literature review so as to identify the real research gaps as well as formulate the scientific questions. To me VOSviewer is able to identify the “keywords” or even “outstanding questions” but definitely is unable to check if those questions have been answered by subsequent research.

Comments on the Quality of English Language

Please refer to the review report.

Author Response

The authors acknowledge and appreciate the reviewer’s comments, and believe that these changes improved the manuscript. All changes are marked in the revised version of the manuscript with Track Changes. The authors would like to highlight the main changes that were made in the manuscript as result of the reviewers’ suggestions:

• The entire manuscript was revised by a native speaker to correct any grammatical errors;
• The abstract was revised to be more specific in its scope and conclusions;
• The total number of articles analysed was corrected to 1479, instead of 1481;
• Figure 4 was changed to remove two time periods where there was no data;
• A note was added to Table 3 to provide full name for the abbreviations.

 

The manuscript reports a comprehensive literature review regarding urban morphology and air quality, etc. using VOSviewer. The findings are interesting and the results presented in Figure 2 (Keyword distribution and their relation), Figure 3 (Contribution % of the different domains per decade of publication), and Figure 5 (Keyword timeline) would be interesting to the audience of the journal. To me the manuscript is acceptable provided that the following two major issues are addressed in the revised manuscript:

1. Use of English:

A comprehensive editing of the use of language is needed. There are quite some grammatical and stylish errors throughout the manuscript, For example, the abstract.

The authors acknowledge the reviewer’s comments. A native English speaker reviewed the text and corrected grammatical and stylistic errors, which are highlighted (with track changes) throughout the manuscript.

 

2. Research Gaps:

To me the software “VOSviewer” hardly identifies the research gaps or formulate the scientific questions. As such, I would suggest the authors, based on the outcome given by VOSviewer, look into the papers, and conduct a detailed, systematic literature review so as to identify the real research gaps as well as formulate the scientific questions. To me VOSviewer is able to identify the “keywords” or even “outstanding questions” but definitely is unable to check if those questions have been answered by subsequent research.

The authors acknowledge the reviewer’s comments. To clarify, the authors have conducted a detailed literature review prior to the VOSviewer application. VOSviewer was not used to perform the main bulk of the literary review, which was based on the classification of papers by their domain (as defined in this study). VOSviewer was used to visualize the results, analyze keywords and complement the literature review. The use of the software is detailed in section 2, lines 167-175.

“Still during the Meta-analysis phase, the results of the literature review were uploaded to the VOSviewer software to create visual maps based on the extracted data. … VOSviewer was also used to construct and visualize the time periods of the publication. The software has been widely used to analyze different articles, and assess and visualize the data networks [22]–[24]...”

Reviewer 3 Report

Comments and Suggestions for Authors

 The growth of cities in the world affects not only the general socio-economic development, but also affects the ecological state. Carbon saturation in the air within cities stimulates the formation of the greenhouse effect, which, in turn, affects climate change on the planet. To minimize harmful effects on the urban environment, city authorities must lead their cities towards a sustainable development. It requires to study previous experience. This article is devoted to establishing the relationship between urban morphology and air quality in a city, which is based on the analysis of bibliographic sources.

In the article, the authors proposed a research methodology that includes the analysis of 1,481 documents from the scientific-metric database Scopus. Based on these articles, 11 domains were classified (i.e. “Urban Morphology”, “Urban Climate”, “Air Quality”, i.e. parameters and factors affecting urban sustainability from the environmental point of view). Bibliographic maps were created using VOSviewer. The authors calculated the number of articles falling into a certain domain, analyzed the connections between different domains, . generalized studies that assess the sustainability of an urban area, using models at a regional scale.

The work was performed at a relatively high methodological level, but the research lacks scientific novelty. In addition, it is necessary to indicate the purpose of the article directly in the article, and not only in the abstract.

Author Response

The authors acknowledge and appreciate the reviewer’s comments, and believe that these changes improved the manuscript. All changes are marked in the revised version of the manuscript with Track Changes. The authors would like to highlight the main changes that were made in the manuscript as result of the reviewers’ suggestions:

• The entire manuscript was revised by a native speaker to correct any grammatical errors;
• The abstract was revised to be more specific in its scope and conclusions;
• The total number of articles analysed was corrected to 1479, instead of 1481;
• Figure 4 was changed to remove two time periods where there was no data;
• A note was added to Table 3 to provide full name for the abbreviations.

 

1) The growth of cities in the world affects not only the general socio-economic development, but also affects the ecological state. Carbon saturation in the air within cities stimulates the formation of the greenhouse effect, which, in turn, affects climate change on the planet. To minimize harmful effects on the urban environment, city authorities must lead their cities towards a sustainable development. It requires to study previous experience. This article is devoted to establishing the relationship between urban morphology and air quality in a city, which is based on the analysis of bibliographic sources.

In the article, the authors proposed a research methodology that includes the analysis of 1,481 documents from the scientific-metric database Scopus. Based on these articles, 11 domains were classified (i.e. “Urban Morphology”, “Urban Climate”, “Air Quality”, i.e. parameters and factors affecting urban sustainability from the environmental point of view). Bibliographic maps were created using VOSviewer. The authors calculated the number of articles falling into a certain domain, analyzed the connections between different domains, . generalized studies that assess the sustainability of an urban area, using models at a regional scale.

The work was performed at a relatively high methodological level, but the research lacks scientific novelty. In addition, it is necessary to indicate the purpose of the article directly in the article, and not only in the abstract.

The authors are thankful to the reviewer’s comments. The scope and purpose of this paper was detailed in the Abstract and in Section 1, lines 79-87.

Regarding the novelty of this study, the purpose of this review is to assess which domains are more prevalent when it comes to studying the sustainability (based on environmental variables) of an urban area, its air quality and its morphology, and the connection, or lack thereof, of those domains. This serves to assess what domains are more prevalent and thus inform future studies of gaps in the research, either in the most common domains, or the ones that are given less importance. Given the diversity of domains related to urban sustainability, at an environmental level, this review is inter- and multi-disciplinary. The complementary assessment with VOSviewer allows to evaluate how authors use keywords, and how those keywords correlate with the domains.

Reviewer 4 Report

Comments and Suggestions for Authors

This manuscript analyzes how urbanization affects air quality and climate change. I believe the following areas deserve greater effort, and I hope you find it useful.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

have no comments

Author Response

The authors acknowledge and appreciate the reviewer’s comments, and believe that these changes improved the manuscript. All changes are marked in the revised version of the manuscript with Track Changes. The authors would like to highlight the main changes that were made in the manuscript as result of the reviewers’ suggestions:

• The entire manuscript was revised by a native speaker to correct any grammatical errors;
• The abstract was revised to be more specific in its scope and conclusions;
• The total number of articles analysed was corrected to 1479, instead of 1481;
• Figure 4 was changed to remove two time periods where there was no data;
• A note was added to Table 3 to provide full name for the abbreviations.

 

This manuscript analyzes how urbanization affects air quality and climate change. I believe the following areas deserve greater effort, and I hope you find it useful.

1. In your abstract, clearly outline the goals and questions of your study. More clarity and specificity are needed in the existing presentation, which is somewhat generic.

The authors acknowledge the reviewer’s comments. The abstract was revised to be more specific, although keeping the size required by Sustainability (200 words). The improved abstract can be read as follows:

“The expected increase of urbanization changes the morphology of urban areas. These changes affect the urban environment and impact several aspects, such as climate, energy, air quality, socioeconomic, among others. Therefore, it is important to lead cities towards a sustainable development. The goal of this paper is to understand which domains should be considered to assess the sustainability of cities, at an environmental level, and with a focus on air quality, and how those domains are connected, based on a comprehensive literature review, which resulted in 1479 articles. Results show that “Urban Climate”, “Air Quality”, “Urban Morphology”, “Health”, “Energy” and “Mobility” are the most common domains in research and that 39% of the articles only assess one domain. It is possible to understand that though 96% of articles contain up to three domains, the great majority do not assess those domains in an integrated way. There are many studies that evaluate important domains of urban areas, however they mostly evaluate these effects isolated, and rarely in tandem. Moving forward, it is important to understand how to best connect the most relevant domains, under an integrated multicriteria approach, thus allowing a more complete assessment of the sustainability of urban areas”

 

2. In line 48-49, you should include more researches to proof it.

The authors acknowledge the reviewer’s comments. The following references were added to line 51.

J. Liang, P. Y. Lin, Y. C. Chen, and J. J. Liang, “Effects of regional air pollutants on respiratory diseases in the basin metropolitan area of central Taiwan,” Sustain. Environ. Res., vol. 33, no. 1, pp. 1–16, 2023, doi: 10.1186/s42834-022-00159-2.

Coelho, J. Ferreira, D. Carvalho, and M. Lopes, “Health Impact Assessment of Air Pollution under a Climate Change Scenario: Methodology and Case Study Application,” Sustain., vol. 14, no. 21, 2022, doi: 10.3390/su142114309.

 

3. Author mentioned it is the first study that identifies the different domains that are evaluated when assessing the sustainability of cities under a context of changing climate, as well as quantifies how those domains connect with each other. But I don't find an accurate connection number or proportion between domain A and domain B.

The connection between domains was address during the analysis of each paper, in Section 3.1, where the patterns of the connections between the domains were assessed (for example, if domain A and B are in the same study, then the study is about a certain topic). However, the authors agree that this is not clear in the manuscript. Lines 79-83 were changed to address this:

“…In this context, this paper aims to identify and understand which domains are considered to assess the sustainability of cities, at an environmental level (focused on environmental variables and not social, economic or political) and with a focus on air quality, how those domains connect with each other, and their temporal trends, based on a comprehensive literature review….”

 

4. Have the authors considered the geographic differences in the articles counted? Different countries draw different boundaries for air pollution, such as

https://doi.org/10.1016/j.atmosenv.2023.119860

https://doi.org/10.1016/j.atmosenv.2007.05.022

The authors acknowledged the different geographical contexts (detailed in Section 4.2, lines 447-451) as a research gap in this study and as a recommendation for future studies. “Throughout this study, the presence of studies in China is very prevalent. Studies in the United States and Europe were also very common. All of these areas have very different geographical and demographical contexts, and the differences in studying land-use development and sustainability between those areas should be detailed in future studies, because it will affect how the different domains interact in those specific contexts.”

 

5. Go a step further and analyze why 96% of the articles did not provide a comprehensive assessment of these areas. Are there common limitations or challenges that contribute to this? This could add to the understanding of the current state of research.

The authors acknowledge the reviewer’s comments and agree that this information was lacking and is important. Lines 424-429 were added to clarify this topic.

“…Therefore, it is not possible to evaluate a system as complex as an urban area by only analyzing one parameter. To the authors knowledge, the assessment of parameters in an isolated manner is only limited by the scope of the studies, meaning that it is up to the authors and stakeholders to change their approach and analyze multiple parameters in an integrated manner. However, it is also of note that, with systems as complex as urban areas, the quantity of parameters and domains required to achieve a complete assessment may be too high to be feasible. Thus, moving forward, it is important to understand how to best study the connections between the parameters and domains…”

 

6. If possible, provide examples of case studies or empirical research that illustrate the application of an integrated multi-criteria approach to assessing urban sustainability.

The authors acknowledge the reviewer’s comments and agree that this paper does not provide concrete examples to illustrate the application of an integrated multi-criteria approach. In fact, this will be the following step of this study as a whole. The authors aim to further explore each study using an integrated approach and investigate in detail the different methodologies adopted and indicators used for assessing urban sustainability. This work is under development and will be the subject of a future publication.

Reviewer 5 Report

Comments and Suggestions for Authors

The manuscript employs bibliometric analysis to assess the sustainability of cities, concentrating on air quality within the context of climate change.The analysis presented in the text is methodologically rigorous and exhibits a high level of eloquence. Nevertheless, there are a few small corrections that need to be taken into consideration.

1. Abstract:

Line 29 - 31 - It is too general and does not provide any recommendations/solutions as being discussed in section 4

 

2. Introduction:

Line 61: In what manner can compact areas with higher population density exhibit a susceptibility to urban heat and air pollutants?

Line 76: The sentence is confusing. What does the term "environmental level" mean? The author may need to provide clarification or define what is referred to as an environmental level.

3. Methodology:

Explain how does the different domains were selected

Figure 1: What do dash lines refer to?

Line 126 - 146 : It is suggested these whole explanations is written in a constructed table or point forms.

Table 3: Provide full name of the abbreviations (i.e: Models)

 

Author Response

The authors acknowledge and appreciate the reviewer’s comments, and believe that these changes improved the manuscript. All changes are marked in the revised version of the manuscript with Track Changes. The authors would like to highlight the main changes that were made in the manuscript as result of the reviewers’ suggestions:

• The entire manuscript was revised by a native speaker to correct any grammatical errors;
• The abstract was revised to be more specific in its scope and conclusions;
• The total number of articles analysed was corrected to 1479, instead of 1481;
• Figure 4 was changed to remove two time periods where there was no data;
• A note was added to Table 3 to provide full name for the abbreviations.

 

1) The manuscript employs bibliometric analysis to assess the sustainability of cities, concentrating on air quality within the context of climate change. The analysis presented in the text is methodologically rigorous and exhibits a high level of eloquence. Nevertheless, there are a few small corrections that need to be taken into consideration.

Abstract:

Line 29 - 31 - It is too general and does not provide any recommendations/solutions as being discussed in section 4

The authors acknowledge the reviewer’s comments. The abstract was rewritten to include more details and provide recommendations arising from the review performed, however due to word limit it is not possible to include more outcomes.

“The expected increase of urbanization changes the morphology of urban areas. These changes affect the urban environment and impact several aspects, such as climate, energy, air quality, socioeconomic, among others. Therefore, it is important to lead cities towards a sustainable development. The goal of this paper is to understand which domains should be considered to assess the sustainability of cities, at an environmental level, and with a focus on air quality, and how those domains are connected, based on a comprehensive literature review, which resulted in 1479 articles. Results show that “Urban Climate”, “Air Quality”, “Urban Morphology”, “Health”, “Energy” and “Mobility” are the most common domains in research and that 39% of articles only assess one domain. It is possible to understand that though 96% of articles contain up to three domains, the great majority do not assess those domains in an integrated way. There are many studies that evaluate important domains of urban areas, however they mostly evaluate these effects isolated, and rarely in tandem. Moving forward, it is important to understand how to best connect the most relevant domains, under an integrated multicriteria approach, thus allowing a more complete assessment of the sustainability of urban areas”

 

2) Introduction

Line 61: In what manner can compact areas with higher population density exhibit a susceptibility to urban heat and air pollutants?

Compact urban areas are usually characterized by the urban heat island effect, where temperatures are higher. Traffic is also more concentrated, which leads to high pollutant emissions in smaller areas. Since compact areas have a higher population density, there are more people that are more exposed to urban heat and air pollutants. Lines 61-62 were rephrased, and references added, to clarify this topic. “…present higher population exposure to urban heat and to air pollutants, because compact areas with higher population density are more affected, since more people (in smaller areas) are exposed to air pollution and higher temperatures [10], [14]–[17]…”

Martins, H., “Urban compaction or dispersion? An air quality modelling study,” Atmos. Environ., 2012, vol. 54, pp. 60–72, doi: 10.1016/j.atmosenv.2012.02.075.

Augusto, B., P. Roebeling, S. Rafael, J. Ferreira, A. Ascenso, and C. Bodilis, “Short and medium- to long-term impacts of nature-based solutions on urban heat,” Sustain. Cities Soc., 2020, vol. 57, no. February, p. 102122, doi: 10.1016/j.scs.2020.102122.

 

 

3) Line 76: The sentence is confusing. What does the term "environmental level" mean? The author may need to provide clarification or define what is referred to as an environmental level.

Environmental level, in this context, focuses the study on environmental variables, and not economic, social or political. Line 81 was changed to clarify this term.

“…the sustainability of cities, at an environmental level (focused on environmental variables and not social, economic or political) and…”

 

4) Methodology:

Explain how does the different domains were selected

The different domains were selected based on the classification of the different papers. As each paper was classified, it either fit an already existing domain, or there was a need to create a new domain. After classifying all of the papers, some domains were grouped because of their similarities. This is detailed in lines 130-135 “…were analyzed and classified according to the topic addressed, i.e. their domain (parameters and factors that affect the urban sustainability, from an environmental perspective), and sometimes with multiple domains. The domains derived from the papers and whenever there was a need, a new domain was added.”.

 

5) Figure 1: What do dash lines refer to?

The dashed lines serve to differentiate the analysis from the results. “VOSviewer”, “Domains” (i.e., the classification of the studies), and “Research Gaps and Recommendations for future work” are considered as outcomes, and not part of the analysis process. This clarification was added to the manuscript in Section 2, lines 119-122.

 

6) Line 126 - 146 : It is suggested these whole explanations is written in a constructed table or point forms.

The authors agree with the reviewer that this would help the reading. The change was made to the manuscript (lines 136-162).

“… domains derived from the papers and whenever there was a need, a new domain was added. In the end, the domains included were:

• “Socioeconomic”, which included cost-benefit studies or any study that considered the cost or other economic parameters;
• “Urban Morphology”, when dealing with urban form, or the effects of urban land use (this excludes papers that focus on changes to, for example, forest areas, or non-urban water bodies); “Urban Climate”, when it is focused on urban microclimate, ranging from urban heat island effect to thermal comfort; it also includes studies where precipitation is assessed;
• “Energy”, which included heat fluxes, energy sources, and air conditioning analysis;
• “Air quality”, which included pollutant emissions and concentrations. Even though “air quality” is a search term, there are studies that do not include it as a domain;
• “Mobility”, both pedestrian and land transport;
• “Health”, comprising thermal comfort, allergens, morbidity, amongst others;
• “Population”, which dealt with population demographics;
• “Urban metabolism” which comprised ecological footprint studies as well as food supply chains;
• “Water resources”, which included wastewater treatments and water pollutants;
• “Sustainability”, which included nature-based solutions and ecological topics,
• “General”, which included the general effects and impacts of climate change as well as papers from conferences where multiple topics were ad-dressed;
• “Other”, when the scope was too alien for the research interest, by error of the search engine. The papers were also classified in terms of the tools used: “Modelling”, which included the use of modelling tools; “Monitoring”, where techniques such as remote sensing, or in-situ measurements were used. This classification is important to understand which tools are used to assess certain domains.

Still during the Meta-analysis phase, the results of the literature review were uploaded to the VOSviewer software to create visual maps based…”

 

7) Table 3: Provide full name of the abbreviations (i.e: Models)

These changes were made in the manuscript as a note to Table 3.

“Notes:

WRF - Weather Research Forecast

MM5 - Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model

LM/LMM - Linear mixed-effects model

STIRPAT - Stochastic Impacts by Regression on Population, Affluence and Technology

RSM - Regional Spectral Model

RegCM3 - Regional Climate Model

CLM3 - NCAR Community Land Model version 3

DRCM - Davis Regional Climate Model, MCCM - Multiscale Climate Chemistry Model

PCM - Parallel Climate Model, MOZART-2 - Model for Ozone and Related Chemical Tracers

CMAQ - Community Multi-scale Air Quality model

CAM5.1 - Community Atmosphere Model version 5.1

CLM4 - Community Land Model version 4

REMO - Regional Model

WETTREG - Weather Situation-based Regionalization Method

SUEWS - Surface Urban Energy and

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The growth of cities in the world affects not only the general socio-economic development, but also affects the ecological state. Carbon saturation in the air within cities stimulates the formation of the greenhouse effect, which, in turn, affects climate change on the planet. To minimize harmful effects on the urban environment, city authorities must lead their cities towards a sustainable development. It requires to study previous experience. This article is devoted to establishing the relationship between urban morphology and air quality in a city, which is based on the analysis of bibliographic sources.

In the article, the authors proposed a research methodology that includes the analysis of 1,481 documents from the scientific-metric database Scopus. Based on these articles, 11 domains were classified (i.e. “Urban Morphology”, “Urban Climate”, “Air Quality”, i.e. parameters and factors affecting urban sustainability from the environmental point of view). Bibliographic maps were created using VOSviewer. The authors calculated the number of articles falling into a certain domain, analyzed the connections between different domains, generalized studies that assess the sustainability of an urban area, using models at a regional scale.

The work was performed at a relatively high methodological level, but the research lacks scientific novelty. In addition, it is necessary to indicate the purpose of the article directly in the article, and not only in the abstract.

I can conclude that the author didn’t account my notices. It’s up to you to approve or not to publication.

Author Response

The authors are thankful for the reviewer’s comments. The sections regarding the scope and purpose of this paper were revised in the first revision of the paper, both in the abstract and in the article directly. Unfortunately, due to the limit of words in the abstract, it was not possible to add all of the information.

Regardless, the authors revised Section 1 to include more details about the purpose and scope of the paper, as well as the scientific novelty. These changes were made in Section 1, lines 74-90.

 

 “…In this context, this paper aims to identify and understand which domains are considered to assess the sustainability of cities, at an environmental level (focused on environmental variables and not social, economic or political) and with a focus on air quality, how those domains connect with each other, and their temporal trends based on a comprehensive literature review. By doing that, this work will not only be interesting to the scientific community, as its outcomes will recognize the current research gaps in the environmental sciences field, but will also be relevant to planners and policymakers since they will give insights about the domains that should be considered to assess and promote cities’ sustainability leading to a better air quality. Given the diversity of domains related to urban sustainability, at an environmental level, this review is inter- and multi-disciplinary. The complementary assessment with VOSviewer allows to evaluate how authors use key-words, and how those keywords correlate with the domains.

This work is distinguishable from previous studies because, as per authors best knowledge, it is the first study that identifies the different domains that are evaluated when assessing the sustainability of cities, with a focus on air quality, under a context of changing climate, as well how those domains connect with each other. By understanding the domains that are, and have been, studied, as well as their connection, it is possible to identify the gaps in research which will inform future studies. …”

 

The authors believe that these changes have improved the manuscript and hope that the new version is in accordance with the reviewer’s standards.

Round 3

Reviewer 3 Report

Comments and Suggestions for Authors

The growth of cities in the world affects not only the general socio-economic development, but also affects the ecological state. Carbon saturation in the air within cities stimulates the formation of the greenhouse effect, which, in turn, affects climate change on the planet. To minimize harmful effects on the urban environment, city authorities must lead their cities towards a sustainable development. It requires to study previous experience. This article is devoted to establishing the relationship between urban morphology and air quality in a city, which is based on the analysis of bibliographic sources.

In the article, the authors proposed a research methodology that includes the analysis of 1,481 documents from the scientific-metric database Scopus. Based on these articles, 11 domains were classified (i.e. “Urban Morphology”, “Urban Climate”, “Air Quality”, i.e. parameters and factors affecting urban sustainability from the environmental point of view). Bibliographic maps were created using VOSviewer. The authors calculated the number of articles falling into a certain domain, analyzed the connections between different domains, . generalized studies that assess the sustainability of an urban area, using models at a regional scale.

 

The work was performed at a relatively high methodological level. The authors revised the paper, explained the scientific novelty and indicated the purpose of the paper directly in the article. I believe that this paper can be published.