Green Infrastructure and Integrated Optimisation Approach Towards Urban Sustainability: Case Study in Altstetten-Albisrieden, Zurich
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript develops a method for optimizing the allocation of green spaces and conducts an empirical analysis using a case study in Zurich, which holds significant research value and practical application potential. However, it is still recommended to enhance the quality of the article from the following aspects:
1) In the introduction section, it is necessary for the author to clarify the concept of urban green infrastructure and the composition of its land use types. This will be helpful for readers who are not familiar with this field. Additionally, there is currently insufficient discussion on the research trends regarding the optimization of the spatial allocation of green infrastructure. For example, there has been a great deal of research accumulated on the layout analysis of park green spaces, street green spaces, pocket parks, etc.
2) Why was a 10-meter grid adopted? I think this scale is relatively small, smaller than the size of an average building. How exactly did N. Dong explain the applicability of this size?
3) In Section 2.3, the author has insufficiently discussed the selection of factors related to urban green infrastructure. Why are these specific indicators chosen?
4) What is the typicality of Altstetten-Albisrieden? Do the relevant analysis results have universal significance?
5) In Figure 3, the adjacency relationship of spatial units is used to represent accessibility, but it seems that the actual terrain and road paths in reality are not considered, which may not be consistent with the real situation. How did the author consider this issue?
6) The author used the DBSCAN method for clustering. It is recommended to try the HDBSCAN algorithm. Relatively speaking, this method can better reflect the actual spatial distance. Therefore, the clustering results may be more accurate.
7) It is recommended that the author, based on the obtained 7-dimensional radar chart and clustering results, discuss the reasons behind the phenomena and compare and discuss them with the findings of previous studies.
8) It seems that the author did not report the number of analysis units. Please supplement this information.
9) Please increase the size of the text in the figures and ensure its clarity.
10) There are multiple citation errors in the main text, such as in lines 202 and 261.
Author Response
Comments 1):The manuscript develops a method for optimizing the allocation of green spaces and conducts an empirical analysis using a case study in Zurich, which holds significant research value and practical application potential. However, it is still recommended to enhance the quality of the article from the following aspects: In the introduction section, it is necessary for the author to clarify the concept of urban green infrastructure and the composition of its land use types. This will be helpful for readers who are not familiar with this field. Additionally, there is currently insufficient discussion on the research trends regarding the optimization of the spatial allocation of green infrastructure. For example, there has been a great deal of research accumulated on the layout analysis of park green spaces, street green spaces, pocket parks, etc.
Response: I express my sincere gratitude for your thoughtful suggestions concerning the introduction section. I have undertaken a comprehensive revision of the entire section to elucidate the background of the study, clarify the definition of urban green infrastructure, and present the current state-of-the-art regarding the benefits associated with urban green infrastructure.
Comments 2): Why was a 10-meter grid adopted? I think this scale is relatively small, smaller than the size of an average building. How exactly did N. Dong explain the applicability of this size?
Response: Thank you for your questions regarding the grid cell size. The study initially employed a 30-meter grid for a pilot study to test the feasibility of the entire approach, as I mentioned in section 4. The decision to use the 30-meter grid was informed by the research conducted by Hong Lv et al. (2023), which found that a grid size of 30 meters achieved the highest accuracy of 82.9% in the comparative assessment, slightly outpacing the grid sizes of 10 and 15 meters. However, the 30-meter grid presented challenges in accurately depicting building outlines in the studied area and resulted in some misleading information. For instance, due to the rapid redevelopment process, some building information was absent but still represented in the grid cells. Consequently, I later referred to the study by Nan Dong et al., which analysed grid cell sizes ranging from 5 to 200 meters. The study concludes that, for population distribution raster data, “a better numeric information expression is achieved when the grid size is 5m and 10m, " and “a better spatial relationship expression is achieved when the grid size is 10m. " I have revised the relevant text in the methods section and added a figure (Figure 2) to illustrate the differences between using the 10-meter grid and the 30-meter grid.
Comments 3): In Section 2.3, the author has insufficiently discussed the selection of factors related to urban green infrastructure. Why are these specific indicators chosen?
Response:Thank you very much for the comments regarding this section. I have revised the text.
Comments 4): What is the typicality of Altstetten-Albisrieden? Do the relevant analysis results have universal significance?
Response: Many thanks for this suggestion. I have added some context in the section 2.2 to explain the typicality of the Altstetten-Albistrienden district.
Comments 5): In Figure 3, the adjacency relationship of spatial units is used to represent accessibility, but it seems that the actual terrain and road paths in reality are not considered, which may not be consistent with the real situation. How did the author consider this issue?
Response: I would like to express my sincere gratitude for highlighting this matter. Indeed, this was one of my primary concerns throughout the study, as I comprehend that the impact of railways and roadways on the natural habitat is significantly more crucial than that of any other grey surface. To date, I have not identified a satisfactory analytical method for this evaluation; therefore, I have only represented railways and roads as grey surfaces in the calculation of the green ratio. I have revised Section 5.3 of the discussion to address the shortcomings of my simplified methodology concerning green connectivity, particularly regarding the effects of railways and roads. A preliminary suggestion to enhance this evaluation involves combining the Digital Elevation Model (DEM) map and applying specific weights to the parameters, such as modes of transportation (rail, highway, street levels, etc.) and traffic intensity (speed limits, one-way versus two-way streets).
Comments 6): The author used the DBSCAN method for clustering. It is recommended to try the HDBSCAN algorithm. Relatively speaking, this method can better reflect the actual spatial distance. Therefore, the clustering results may be more accurate.
Response: I sincerely appreciate your suggestion regarding the clustering methods. The study explored various clustering algorithms, including K-Means, DBSCAN, and GMM, based on the dataset's distribution. However, the outcomes yielded by DBSCAN were not satisfactory and significantly deviated from my initial expectations. Consequently, the study opted to proceed with the results obtained from K-Means and GMM. After carefully reviewing the feedback, I implemented the HDBSCAN algorithm to determine whether the results could be enhanced. By adjusting the minPts parameter from 2 to 15, the number of clusters was observed to decrease from 6 to 2, all exhibiting highly uneven distributions of data points within the clusters. I have included Figure 9 in Section 3.5 to depict the differing results from all the clustering methods applied, including HDBSCAN. Given that the clustering process is pivotal to the study, my further research will also concentrate on identifying a more effective or appropriate algorithm to enhance the clustering process.
Comments 7): It is recommended that the author, based on the obtained 7-dimensional radar chart and clustering results, discuss the reasons behind the phenomena and compare and discuss them with the findings of previous studies.
Response: I incredibly appreciate your suggestion regarding the discussion on the clustering results and findings. I added one paragraph in the discussion section 5.1.
Comments 8): It seems that the author did not report the number of analysis units. Please supplement this information.
Response: Many thanks for pointing out this missing information in the study. I have added it in the session 2.5 and 3.5.
Comments 9): Please increase the size of the text in the figures and ensure its clarity.
Response: Many thanks for the suggestion. I have updated all figures.
Comments 10): There are multiple citation errors in the main text, such as in lines 202 and 261.
Response: I sincerely appreciate your identifying this issue. It arose during the process of aligning my text with the specified journal template. I have rectified the particular reference along with the associated text and thoroughly reviewed the entire document to prevent similar oversights resulting from my oversight.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe presented paper for the review is well-structured, and it discusses the results of valuable research. However, despite the well-described results sections, the paper lacks a strong and robust introduction, with a clearly defined goal of the research, followed by the research questions. This rather weak introduction (as it’s not catchy for the readers in its present form) makes it difficult to understand the paper's main purpose. Also, the conclusion section is not convincing. There is no “message to take home”, resulting from the paper's blurred goal. I would suggest revising the introductory and conclusion sections thoroughly.
Detailed comments:
Lines 19-20: Information about the radar charts in the abstract is not in the right place, as this is technical information.
The abstract lacks information on actual findings – it just states that the study provides a thorough analysis of urban green space provision in Altstetten-Albisrieden, presenting extensive recommendations for optimizing green space planning, but in fact, the readers won’t find information on these recommendations.
In the paper’s first sentence, it’s unclear what is meant by Authors by “in terms of number, density, and dimensions”. Starting a paper with a strong and clear statement is very important.
The Introduction lacks a clearly stated research question(s) and the paper’s goal. Without that, it’s very difficult to understand the idea behind it. Summarizing the paper's organization, which is placed at the end of the introduction, cannot replace the properly elaborated aim of the paper.
Methods:
The first lines in the Methods section explain the paper’s aim. However, it would be better to end the introduction with a clear goal definition, and here describe the methodology. At present, the aim is very vague and general, so it’s difficult to assess if the chosen methods are proper, etc. What the goal is, what you want to achieve, and what methods are applied should be made transparent.
Line 83: The initial phase involved assessing the availability of green space – but what kind of availability do you mean? Physical availability meant a direct connection to the green space or other? Depending on the meaning of ‘availability,’ various factors should be selected and studied. For example, it’s not clear what’s the relation between leaf area and green space accessibility.
Fig. 1. The figure does not explain the 4 stages of the methodology. It would be beneficial to include stages of the study linked with applied methods, not only link the factors analyzed.
Lines 202, 261: There’s some problem with the reference.
Author Response
Comment 1): The presented paper for the review is well-structured, and it discusses the results of valuable research. However, despite the well-described results sections, the paper lacks a strong and robust introduction, with a clearly defined goal of the research, followed by the research questions. This rather weak introduction (as it’s not catchy for the readers in its present form) makes it difficult to understand the paper's main purpose. Also, the conclusion section is not convincing. There is no “message to take home”, resulting from the paper's blurred goal. I would suggest revising the introductory and conclusion sections thoroughly.
Response: I would like to express my sincere gratitude for highlighting this matter. I have updated the text of introduction and conclusion.
Comment 2): Lines 19-20: Information about the radar charts in the abstract is not in the right place, as this is technical information.
Response:Thank you very much for the comments regarding the abstract. I have revised the abstract.
Comment 3): The abstract lacks information on actual findings – it just states that the study provides a thorough analysis of urban green space provision in Altstetten-Albisrieden, presenting extensive recommendations for optimizing green space planning, but in fact, the readers won’t find information on these recommendations.
Response:Thank you very much for the comments regarding the abstract. I have revised the abstract.
Comment 4): In the paper’s first sentence, it’s unclear what is meant by Authors by “in terms of number, density, and dimensions”. Starting a paper with a strong and clear statement is very important.
Response:Thank you very much for the comments regarding the introduction section. I have rewritten the inntroduction section.
Comment 5): The Introduction lacks a clearly stated research question(s) and the paper’s goal. Without that, it’s very difficult to understand the idea behind it. Summarizing the paper's organization, which is placed at the end of the introduction, cannot replace the properly elaborated aim of the paper.
Response:Thank you very much for the above two comments regarding the introduction section. I have undertaken a comprehensive revision of the entire section to elucidate the background of the study, clarify the definition of urban green infrastructure, present the current state-of-the-art regarding the benefits associated with urban green infrastructure, and describe the context of this study, research question and aims.
Comment 6): The first lines in the Methods section explain the paper’s aim. However, it would be better to end the introduction with a clear goal definition, and here describe the methodology. At present, the aim is very vague and general, so it’s difficult to assess if the chosen methods are proper, etc. What the goal is, what you want to achieve, and what methods are applied should be made transparent.
Response:Thank you very much for the suggestion regarding the methodologies and framework section (2.1). I have revised the text.
Comment 7): Line 83: The initial phase involved assessing the availability of green space – but what kind of availability do you mean? Physical availability meant a direct connection to the green space or other? Depending on the meaning of ‘availability,’ various factors should be selected and studied. For example, it’s not clear what’s the relation between leaf area and green space accessibility.
Response:Thank you very much for the comments regarding this section. I have revised the text.
Comment 8): Fig. 1. The figure does not explain the 4 stages of the methodology. It would be beneficial to include stages of the study linked with applied methods, not only link the factors analyzed.
Response:Thank you for your comment about the methodology figure. I have revised Figure 1 and Section 2.1 accordingly
Comment 9): Lines 202, 261: There’s some problem with the reference.
Response: I sincerely appreciate your identifying this issue. It arose during the process of aligning my text with the specified journal template. I have rectified the particular reference along with the associated text and thoroughly reviewed the entire document to prevent similar oversights resulting from my oversight.
Reviewer 3 Report
Comments and Suggestions for AuthorsThis is an interesting paper concerning important problem: development of high quality green infrastructure in urbanized areas. Topic is really important, as regards cities adaptation to climate change and, in strict connection with that, residents well-being including accessibility to green areas. There is a lot of previous scientific research concerning these issues, but presented study has some specific features / elements, especially methodical ones, which are inspiring for other scientists and may be called innovative. The aim of the study was to find and check the integrated methodology to optimise the location and planning of green space network in urbanized areas, putting attention to natural green quality and inhabitants well-being created by using high quality greenery and good accessibility to green infrastructure. The presented study referes well to desirable model of the city of future (promoted in European Union in the expertise from 2011, edited by UE).
Methodical approach is the most interesting / valuable content of presented study. It is, in general, performed well in the Figure 1 (Methodological framework). This methodical approach is constructed (created) on solid scientific bases, including results of current ecological research; the Authors took as parameters such important features of green areas, as: green surface area, leaf area, green connectivity, tree data, green ratio; supported by current tools, as geo-information, OpenStreetMap and grid-based method (using square 10-meter grid) of spatial recognition. The whole article is elaborated well and written clearly, as regards all subsections, including conclusions. Paper also contains discussion on its research limitation and indicates directions of further investigations.
The only disadvantage is that the square grid net (method used in the research) has little to do with the real boundaries of city units / plots; so the results give a general concept / information, but are not very precised as regards spatial distribution and shapes of different types of land use.
Author Response
Comment: This is an interesting paper concerning important problem: development of high quality green infrastructure in urbanized areas. Topic is really important, as regards cities adaptation to climate change and, in strict connection with that, residents well-being including accessibility to green areas. There is a lot of previous scientific research concerning these issues, but presented study has some specific features / elements, especially methodical ones, which are inspiring for other scientists and may be called innovative. The aim of the study was to find and check the integrated methodology to optimise the location and planning of green space network in urbanized areas, putting attention to natural green quality and inhabitants well-being created by using high quality greenery and good accessibility to green infrastructure. The presented study referes well to desirable model of the city of future (promoted in European Union in the expertise from 2011, edited by UE).
Methodical approach is the most interesting / valuable content of presented study. It is, in general, performed well in the Figure 1 (Methodological framework). This methodical approach is constructed (created) on solid scientific bases, including results of current ecological research; the Authors took as parameters such important features of green areas, as: green surface area, leaf area, green connectivity, tree data, green ratio; supported by current tools, as geo-information, OpenStreetMap and grid-based method (using square 10-meter grid) of spatial recognition. The whole article is elaborated well and written clearly, as regards all subsections, including conclusions. Paper also contains discussion on its research limitation and indicates directions of further investigations.
The only disadvantage is that the square grid net (method used in the research) has little to do with the real boundaries of city units / plots; so the results give a general concept / information, but are not very precised as regards spatial distribution and shapes of different types of land use.
Response: I would like to express my sincere gratitude for your thoughtful and encouraging feedback on the manuscript. I wholeheartedly concur with your concern regarding the utilisation of a grid net in lieu of actual land parcel boundaries throughout the analytical process. This represents a significant consideration of the study. Initially, the analysis was executed based on land parcels. As the research progressed, I identified two phenomena: 1) numerous developments were constructed across adjacent plots, and 2) certain plots were subdivided into smaller segments for various developments. These phenomena raised questions regarding the accurate delineation of land plot boundaries; however, a lack of official information hindered further validation. Additionally, I encountered an issue while evaluating the accessibility of public green spaces, as different segments of a larger plot might exhibit varying quantities or sizes of accessible public green spaces. In order to circumvent these complications and streamline the analysis, I opted to adopt a grid net as a foundational basis to standardise the evaluation of seven factors within each grid unit. Nonetheless, your observations underscored a critical aspect of the analytical approach. As a result, I have revised section 2.5 and incorporated an additional discussion in the section 5.2 pertaining to future research in this area.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript has been thoroughly revised and optimized based on my comments. All my concerns have been addressed, and I recommend its acceptance.
