A Simulation Study of the Impact of Urban Street Greening on the Thermal Comfort in Street Canyons on Hot and Cold Days
Round 1
Reviewer 1 Report (New Reviewer)
Comments and Suggestions for AuthorsI appreciate the efforts take by the author in writing the manuscript. However the following are the comments/suggestion need to be incorporated.
1. While the paper discusses the importance of vegetation and green cover, the abstract lacks the clarity and flow in terms of aim and objectives of the study along with need and gaps found in the previous studies. The contribution of the study to the relevance field can also be highlighted.
2. Ensure that the language used in abstract and conclusion is quantitative results in terms of metrics such as temperature variations, PET values etc.
3. The Methodology part of the paper can benefit from labelling of photographs and graphs with details. The need of selection for study area and a rationale for the same will be helpful.
4. The addition of references for input parameters of study for the study can help to understand the details.
5. The duration for data collection for winter months of the study has a discrepancy in the data collection (Page 5 line 168, time mentioned for winter as 10.00 to 18.00). The misprinting can be modified in the paper.
6. The detailed analysis of the generalized findings can be presented in a tabular format or through illustrations could lend further credibility to your results.
7. The results don’t showcase an optimized strategy for the yearly comfort, rather has a similar analysis of seasonal data as previous studies. The street canyon study has been identified as a major parameter, but previously researchers have already worked on street canyons with different aspect ratios.
8. Conclusion Section needs to be revised and specific conclusions need to be presented.
Author Response
I appreciate the efforts take by the author in writing the manuscript. However the following are the comments/suggestion need to be incorporated. Thanks quite a lot for your participation in the review process and also your valuable suggestions. We really hope this article can be published and will try our best to improve the article and make it meet the requirements.
Suggestion 1: While the paper discusses the importance of vegetation and green cover, the abstract lacks the clarity and flow in terms of aim and objectives of the study along with need and gaps found in the previous studies. The contribution of the study to the relevance field can also be highlighted.
Comment 1: We have rewritten the abstract to clarify the aim and objectives of the study along with the need and gaps found in the previous studies. We have highlighted the importance of this research to relevant field. It is the last paragraph of the abstract.
Suggestion 2: 2. Ensure that the language used in abstract and conclusion is quantitative results in terms of metrics such as temperature variations, PET values etc.
Comment 2: We have added many quantitative results in the abstract and conclusion.
Suggestion 3: 3. The Methodology part of the paper can benefit from labelling of photographs and graphs with details. The need of selection for study area and a rationale for the same will be helpful.
Comment 3: We have labelled photographs and graphs with details. We are sorry. We are not sure whether we totally understand what we need to do. We have added the rationale for the selection of the study city and study area in the first and second paragraph of the 2.1 Selection of the study time and area part. If we need to add more information, please tell us, we will add in next round of revision.
Suggestion 4: 4. The addition of references for input parameters of study for the study can help to understand the details.
Comment 4: We are sorry. We are not sure whether we totally understand what we need to do. We have added references for the the influencing factors, which we chose to explore their impacts on the thermal comfort of the street canyon in hot and cold days. Please see the new first paragrapgh of section 2.3 Model building and simulation analysis for the details we have added. If we need to add more information, please tell us, we will add in next round of revision.
Suggestion 5: 5. The duration for data collection for winter months of the study has a discrepancy in the data collection (Page 5 line 168, time mentioned for winter as 10.00 to 18.00). The misprinting can be modified in the paper.
Comment 5: Thanks for your reminding and I am very sorry for the negligence. I have changed the timeframe to from 10:00 to 19:00 on December 16, 2022.
Suggestion 6: 6. The detailed analysis of the generalized findings can be presented in a tabular format or through illustrations could lend further credibility to your results.
Comment 6: We have added a table 9 in 3.2 Discussion part to show the detailed analysis of the generalized findings.
Suggestion 7: 7. The results don’t showcase an optimized strategy for the yearly comfort, rather has a similar analysis of seasonal data as previous studies. The street canyon study has been identified as a major parameter, but previously researchers have already worked on street canyons with different aspect ratios.
Comment 7: We have added a new “3.2 discussion part” to show the discussion and originity of the research. We chose hot summer and cold winter area and focuses on the comparision of the impacts of trees and buildings on the thermal comfort of the street canyon in hot days and cold days. The street trees are evergreen. We try to explore whether this is a good spatial pattern of street canyons that can achieve the goal of reducing temperature as much as possible in summer and increasing temperature as much as possible in winter? After the research, We believe that there is no spatial pattern of street canyons that can achieve the goal of reducing temperature as much as possible in summer and increasing temperature as much as possible in winter. We believe that improving the thermal comfort of the street canyon on hot and cold days by improving the green space and buildings on both sides is more of a trade-off, that is, trying to have a greater positive impact on the thermal comfort of hot or cold days while minimizing the negative impact on the thermal comfort of cold or hot days. Due to differences in conditions like annual average temperature, dominant wind direction, street direction, street width, building height, and street tree species among different street canyons, there is no single good street canyon spatial form that can suit for all street canyon areas.
Suggestion 8: 8. Conclusion Section needs to be revised and specific conclusions need to be presented.
Comment 8: Our study focuses on the exploration of different effects of same street tree and building layouts on the thermal comfort at hot and cold days. We have divided the conclusion section into two paragraphs. The first paragraph focuses on summarizing relevant data, and we have added relevant data as required.The second paragraph focuses on explaining that no one optimization strategy can suit all different environments. We believe that we should traff off the advantages and disadvantages of street canyons spatial pattern during hot and cold days at the same time. We should maximize the advantages and minimize the disadvantages. Since different street canyon environments have different specific situations like dominant wind direction and speed, bulding height, street widths, tree canopy density and so on.We suggest following researchers highlight the thermal comfort at hot and cold days at the same time and make the optimization strategy based on the specifc situation of different street canyons.
Reviewer 2 Report (New Reviewer)
Comments and Suggestions for Authors1. Add more keywords. Avoid numbering results. Add connective words to include multiple results in the abstract.
2. In the introduction, paragraph 1, add more information. How do UHI and global warming impact comfort and health? This reasoning will be available in the article you already referred to.
3. Lines 158 to 160, if you are referring to studies from other countries, provide relevant references to these studies. Also, make sure these studies are from similar climate zones. If you compare two different climate zones the thresholds will vary widely.
4. Section 2.2 - take care of formatting.
5. Add discussions chapter with main findings and recommendations for future work.
Comments on the Quality of English LanguageMinor editing of English language required.
Author Response
Thanks quite a lot for your participation in the review process and also your valuable suggestions. We really hope this article can be published and will try our best to improve the article and make it meet the requirements.
Suggestion 1: 1. Add more keywords. Avoid numbering results. Add connective words to include multiple results in the abstract.
Comment 1: We have added more keywords, use connective words to include multiple results and avoid numbering results in the abstract.
2. In the introduction, paragraph 1, add more information. How do UHI and global warming impact comfort and health? This reasoning will be available in the article you already referred to.
Comment 2: We have added reasons about how UHI and global warming impact comfort and health in the paragraph 1 of the introduction.
3. Lines 158 to 160, if you are referring to studies from other countries, provide relevant references to these studies. Also, make sure these studies are from similar climate zones. If you compare two different climate zones the thresholds will vary widely.
Comment 3: We are sorry. This comfortable temperature range was pointed out by the China Meteorological Administration. We have revised the sentences in the article. This comfort range has been recognized by Chinese researchers due to its official recognition. We have added references for the relevant information.
Suggestion 4:4. Section 2.2 - take care of formatting.
Comment 4: Thanks for your suggestion. We have carefully checked the formatting and revised relevant issues.
5. Add discussions chapter with main findings and recommendations for future work.
Comment 5: We have added a discussion part. Please see the 3.2 Discussion part in the revised article for details.
Round 2
Reviewer 1 Report (New Reviewer)
Comments and Suggestions for AuthorsThe Comments have been incorporated in the manuscript. However Proofreading and paper formatting as per journals requirements is required.
Reviewer 2 Report (New Reviewer)
Comments and Suggestions for AuthorsMy comments are addressed.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript (hereinafter referred to as the MS) aims to examine the effects of vegetation and buildings on thermal comfort in urban street canyons. The topic is relevant, and the MS is well-written. However, there are some parts of the MS which need to be explained, especially regarding the methods and the discussion of the results.
Major comments:
(1) Please explain the geographical and climatological conditions of Changsha more thoroughly by naming the basin in which it is located and by using the Köppen climate classification.
(2) Please provide detailed formulas for all the measures - i.e., PET, R2, index of agreement - which were used in the MS. Upon to the reviewer’s knowledge the coefficient of determination (R2) is related to the topic of regression. Please explain how the R2 was calculated.
(3) Please explain how the following sentence relates to the topic of the MS? “To explore the impact of street trees on the concentration of PM2.5 in street canyons, researchers first replaced the street trees on both sides of the road in Model 1 with those with the same features as those in Model 1 and a LAD of 1.1 m3/m2 which was different from that in Model 1, and built Model 2.”
(4) In Section 2 “researchers” are mentioned several times. For example on page 6: “Researchers imported the model made in Sketch up into ENVI-met through the INX […]”). Are you referring to Liu et al. (2022; DOI: 10.3390/su141912378)? If yes, then please add the reference to the MS.
(5) Please provide figures of Models 1-5 similar to Figure 2 or provide a table which contains the main differences between the Models. For example, the description of Model 5 is on page 8 while the descriptions of other Models are on page 6. This makes it difficult to understand the conclusions of the MS.
(6) Please extend Section 3 which contains the discussion with the followings. The results should be discussed based on the perspective of previous studies. This is completely missing from the MS. Please explain the novelty of the MS compared to previous studies.
(7) Please explain why May 13 was selected for the measurings? Was it examined if the conclusions of the MS are valid for other days, thus for a typical winter day also? If not, then please specify this in the conclusion.
(8) Please explain why was the wind speed measured only at 12 pm on the selected day as it can be seen in Table 2?
(9) In Figure 4 the categories of the PET values were created based on a nonlinear scale. Please explain why.
Other comments:
(1) Please cite papers instead of writing „some researchers” in the following sentence on page 2: „Besides, some researchers focused on the impact of road greening on the thermal comfort [...].”
(2) The reviewer suggests the relocation of the following sentence on page 4 to the discussion of the results: “This researcher felt the impact of the shadow of street trees.”
(3) Please recreate figures in better quality, especially in cases of Figures 3-4.
(4) The reviewer suggests to explain the meaning of black colour in the title of Figure 4 also.
Author Response
Comments and Suggestions for Authors
Suggestion 1: This manuscript (hereinafter referred to as the MS) aims to examine the effects of vegetation and buildings on thermal comfort in urban street canyons. The topic is relevant, and the MS is well-written. However, there are some parts of the MS which need to be explained, especially regarding the methods and the discussion of the results.
Comment 1: Thanks for participating in the review. We will try our best to improve the article based on your guidance. We have provided a more specific introduction to the method part. We have almost rewritten the discussion part. We hope this article becomes clear now. By the way, we have added winter simulations and have provided a more specific introduction to the thermal comfort of street canyons in different models using simulated values of temperature, humidity, and wind speed. This article has enriched a lot of content, and there have been some changes in the theme. You can refer to our abstract for details.
Major comments:
Suggestion 2: (1) Please explain the geographical and climatological conditions of Changsha more thoroughly by naming the basin in which it is located and by using the Köppen climate classification.
Comment 2: We have added the name of the basin in which it is located and used the Köppen climate classification to describe the climate class and condition.
“It is located on the western margin of the Changliu basin and far from the sea.”
“According to Köppen-Geiger climate classification updated by Beck et al.,(2018), Changsha is located in Cfa of the climate classes (information is obtained from the present-day map), that is temperate, hot summers without a dry season.”
Suggestion 3: (2) Please provide detailed formulas for all the measures - i.e., PET, R2, index of agreement - which were used in the MS. Upon to the reviewer’s knowledge the coefficient of determination (R2) is related to the topic of regression. Please explain how the R2 was calculated.
Comment 3: We have added detailed formula for PET, RMSE, R2, and index of agreement. You can find the deatial in the corresponding part of the revised manuscript.
Suggestion 4: (3) Please explain how the following sentence relates to the topic of the MS? “To explore the impact of street trees on the concentration of PM2.5 in street canyons, researchers first replaced the street trees on both sides of the road in Model 1 with those with the same features as those in Model 1 and a LAD of 1.1 m3/m2 which was different from that in Model 1, and built Model 2.”
Comment 4: We have explained the reason in the article.
“The tree canopy plays an important role in improving thermal comfort, in order to better explore the different effects of tree canopy characteristics on street canyon thermal comfort. LAD, as an indicator of leaf area per unit area, can well reflect the different situations of tree canopy. This study attempts to explore the differences in comfort of street canyon environments under different LAD conditions.”
Suggestion 5: (4) In Section 2 “researchers” are mentioned several times. For example on page 6: “Researchers imported the model made in Sketch up into ENVI-met through the INX […]”). Are you referring to Liu et al. (2022; DOI: 10.3390/su141912378)? If yes, then please add the reference to the MS.
Comment 5: I am sorry. The “researchers” mentioned in section 2 are the authors of this article. I have changed all “researchers” in the section to “we”. I think this can make the expression clearer. By the way, this study was conducted independently, and we did not use data from other previous studies. This article differs from (2022; DOI: 10.3390/su141912378) in terms of research time, location, and method, content and so on.
Suggestion 6: (5) Please provide figures of Models 1-5 similar to Figure 2 or provide a table which contains the main differences between the Models. For example, the description of Model 5 is on page 8 while the descriptions of other Models are on page 6. This makes it difficult to understand the conclusions of the MS.
Comment 6: We have provided tables which contain the main differences between the Models (Please see tables 3 and 4). We have made pictures which include three-dimensional views of the six models (Please see figures 2 and 3).
Suggestion 7: ( (6) Please extend Section 3 which contains the discussion with the followings. The results should be discussed based on the perspective of previous studies. This is completely missing from the MS. Please explain the novelty of the MS compared to previous studies.
Comment 7: We have added a large number of citations in the discussion part and conducted the discussion of this study based on previous research results
Suggestion 8: (7) Please explain why May 13 was selected for the measurings? Was it examined if the conclusions of the MS are valid for other days, thus for a typical winter day also? If not, then please specify this in the conclusion.
Comment 8: We have added a new simulation based on the situation on December 16, 2022. Now two simulation days (May 13, 2023 and December 16, 2022) can represent the situation of summer and winter, respectively.We have explained why May 13 was selected for the measuring in the third paragraph of the section 2.1. “According to the traditional Chinese lunar calendar, ; May 13, 2023 (Gregorian calendar date) belongs to summer after the solar term beginning of the summer and before the solar term beginning of the autumn. December 16, 2022 (Gregorian calendar date) belongs to winter after the solar term beginning of the winter and before the solar term beginning of the spring.Using these two days for research is undoubtedly a great way to explore the conditions of hot days and cold days. “. We have already explained in the conclusion section “The hot days (May 13th, 2023) and cold days (December 16th, 2022) we selected are representative, and after reasonable simulation in ENVI-met, they can represent the impact of trees and buildings on the thermal comfort of the street canyon in all hot and cold days in the study area( Bruse and Fleer, 1998; Huttner, 2012). ”
Suggestion 9: (8) Please explain why was the wind speed measured only at 12 pm on the selected day as it can be seen in Table 2?”
Comment 9: We are very sorry that our expression was not clear enough. The wind speed is not the 12 o'clock wind speed, but the average wind speed throughout the entire simulation period (10:00-18:00, December 16th, 2022). ENVI met software has two modes to choose from during simulation: simple forcing and full forcing. Although Simple forcing can set different temperatures and humidity per hour, it can only set a fixed wind direction and speed. Although Full Forcing can set different wind directions and speeds per hour. However, if the actual wind direction and speed change significantly every hour, it will cause the software to report an error and cannot simulate properly. In this case, we can only choose simple forcing mode and set a fixed wind direction and speed. The wind speed and direction we set are actually the average wind speed and direction during the research period. We have removed the wind direction and speed information from the table and provided explanations in the text.
Suggestion 10: (9) In Figure 4 the categories of the PET values were created based on a nonlinear scale. Please explain why.10
Comment 10: We are very sorry that we did not explain the meaning of Figure 4. Figure 4 is a plan view of PET simulation results at a height of 1 meters for each model obtained by simulating in ENVI-met software. The different PET values in the figure represent the simulated PET values of different areas of each model at 12 o'clock. We have added the explanation.
Other comments:
Suggestion 11: (1) Please cite papers instead of writing „some researchers” in the following sentence on page 2: „Besides, some researchers focused on the impact of road greening on the thermal comfort [...].”
Comment 11: We have sorry. We have cited the researches related to this sentence.
“Some researchers have studied the impact of street trees on thermal comfort in street canyons (Ren et al., 2022; Martini et al. 2020; Li et al. 2023; Cao et al. 2022; Narimani et al. 2022; Zhang et al. 2022; Huang et al. 2020).” By the way, this is a starting sentence, followed by the introduction of detailed researches in this field.
We have rewritten the sentences “Besides, some researchers focused on the impact of road greening on the thermal comfort” to “Besides, Cui et al., (2023) found in their study that when the street orientation and vegetation distribution are the same, if the aspect ratio is 0.9, the thermal comfort of the street canyon is the best. This indicates that the same road greening features may have different effects on thermal comfort in different street canyon environments”
Suggestion 12: (2) The reviewer suggests the relocation of the following sentence on page 4 to the discussion of the results: “This researcher felt the impact of the shadow of street trees.”
Comment 12: We have relocated the sentence to the discussion part.
Suggestion 13: (3) Please recreate figures in better quality, especially in cases of Figures 3-4.
Comment 13: I'm so sorry, the unclear image you saw was caused by my Microsoft Word not being set properly. I have recreated the relevant images and checked the clarity of the images.
Suggestion 14: (4) The reviewer suggests to explain the meaning of black colour in the title of Figure 4 also.
Comment 14：I'm not sure if I fully understand what you mean. I have already explained the meaning of the black area in the title of Figure 4. The new title of figure 4 is “Figure 4. Simulation results of PET values in each model at 12 o’clock (In the figure, the black area represents the area occupied by buildings, which PET value is not available at this height)” Figure 4 is a plane distribution map of PET at a height of 1 meter in the study area. The black area represents the area where the building is located, so it does not have a PET value.
Reviewer 2 Report
Comments and Suggestions for AuthorsThis article tried to investigate the effects of the existence of street greening such as trees and hedges and buildings, and its leave area index on human thermal sensation, PET. However, there are several concerns: at first, in the results, only PET results were shown, and all results were not explained of the reason, which should be explained by the effects of microclimatic factors such as air temp., relative humidity, wind speed, or mean radiant temperature. Moreover, the microclimatic results should be included as a table. Secondly, the five models were explained in only descriptive explanations, so they should be shown as figures. Thirdly, the quality of all images should be better. It is hard to understand the information in the images. Fourthly, this study tested only one wind direction, 225°. Usually, simulation studies test several wind directions, so this study’s results are very limited. If the wind direction is changed same as the street direction, the results can be different. Therefore, this study requires more development to be published because the results of this study are well-known.
Minor concerns listed below:
1. Change all “temperature” to “air temperature”.
2. In line 42 of page 2, correct “He” to “They”.
3. In line 57 of page 2, correct “(ratio of width and height of road” to “a ratio of building height and street width”.
4. In lines 103-105 of page 3, the sentence is unclear. Please modify it to be better understandable.
5. In line 109 of page 3, “First” was only used. There are no more numbers further.
Comments on the Quality of English LanguageMinor revision is required.
Author Response
Suggestion 1: This article tried to investigate the effects of the existence of street greening such as trees and hedges and buildings, and its leave area index on human thermal sensation, PET. However, there are several concerns: at first, in the results, only PET results were shown, and all results were not explained of the reason, which should be explained by the effects of microclimatic factors such as air temp., relative humidity, wind speed, or mean radiant temperature.
Comment 1: Thanks for participating in the revision. We have tried our best to revise the article based on your guidance. We really hope to gradually improve this article and make it meet the publishing requirements under your guidance. We have added the average values of street canyon temperature, humidity, and wind speed for each model (Model 1-6) at each time period. We have compared the average values of temperature, humidity, and wind speed of each model at each time period using tables and line graphs. We have rewritten our discussion section. We have added a lot of discussion on the relevant research of previous researchers. We specifically explained the reasons behind the PET situation in each model at different time periods in the discussion section on temperature, humidity, and wind speed. Please refer to the corresponding content in the article for details. By the way, we have added a simulation for the cold winter day of December 16, 2022 from 11:00 to 19:00.
Suggestion 2: Moreover, the microclimatic results should be included as a table.
Comment 2: We record the PET, air temperature, relative humidity, and wind speed of each simulation time for two different time periods (on May 13, 2023, and on December 16, 2022) in tables format. Please refer to table 5-12 in the article.
Suggestion 3: Secondly, the five models were explained in only descriptive explanations, so they should be shown as figures.
Comment 3: We have shown the differences of 6 models in the figures (we added a model 6 with different wind directions based on your suggestion). Because we added winter simulation. We use two pictures to represent these. One figure for the 6 models of summer time simulation and another one for the 6 models of winter time simulation (you can see the detail in the Figure 2 and 3 in the revised manuscript).
Suggestion 4: Thirdly, the quality of all images should be better. It is hard to understand the information in the images.
Comment 4: I'm so sorry, the unclear image you saw was caused by my Microsoft Word not being set properly. I have recreated the relevant images and checked the clarity of the images.
Suggestion 5: Fourthly, this study tested only one wind direction, 225°. Usually, simulation studies test several wind directions, so this study’s results are very limited. If the wind direction is changed same as the street direction, the results can be different. Therefore, this study requires more development to be published because the results of this study are well-known.
Comment 5: We have added models with different wind directions. The wind direction of Model 1-5 in the simulation on May 13, 2023 (the summer day in the Chinese lunar calendar) is 225.0 °. On this basis, we have added a new model 6, which differs only from model 1 in that its wind direction is 90.0 ° (parallel to the direction of the street). We have added simulation results of a cold day December 16, 2022 (a winter day in the Chinese lunar calendar). The wind direction of model 1-5 in the simulation of this day was 47.9 °. The wind direction of Model 6 is 180 °. The wind direction in Model 6 is perpendicular to the direction of the street. In addition, our focus has been changed to the different impacts of plants and buildings on street canyons in summer and winter, as detailed in our abstract.
Minor concerns listed below:
Suggestion 6: 1. Change all “temperature” to “air temperature”.
Comment 6: We are sorry. We have changed all “temperature” to “air temperature”.
Suggestion 7: 2. In line 42 of page 2, correct “He” to “They”.
Comment 7: I am so sorry for the negligence. I will be more careful to avoid similar error happen again.
Suggestion 8: 3. In line 57 of page 2, correct “(ratio of width and height of road” to “a ratio of building height and street width”.
Comment 8: Thanks quite a lot for pointing out this kind of error. I have carefully check the whole article to avoid similar unclear expression.
Suggestion 9: 4. In lines 103-105 of page 3, the sentence is unclear. Please modify it to be better understandable.
Comment 9: We are sorry we have rewritten the sentences.
“Many different methods can be used to achieve the effect of improving the thermal comfort of street canyons. In the past, many researchers have focused on how to improve the summer thermal comfort of street canyons to a greater extent when using the same method. For example, when researchers study the impact of street aspect ratio on the thermal comfort of street canyons, they often focus on what is the best aspect ratio for the summer thermal comfort of the street canyon. At the same time, many researchers neglected to explore, among many different methods (such as changing the number of street valley trees, constructing ventilation corridors, and changing the aspect ratio of the street) which method or methods can easily improve the thermal comfort of street canyons to a large extent based on the actual situation of the street canyons. In addition, due to the increasing importance of the heat island effect worldwide, many researchers have only conducted research on how to improve the thermal comfort of street canyons on hot days. At the same time, some researchers have overlooked whether their optimization plan will have a significant negative impact on the thermal comfort of street valleys in winter.”
Suggestion 10: 5. In line 109 of page 3, “First” was only used. There are no more numbers further.
Comment 10: We are sorry. I have deleted the “First”.
Reviewer 3 Report
Comments and Suggestions for AuthorsThere is no novelty in this paper. Data and method were not present appropriately.
Please find the references that directly connected with PET and ENVI-met
I stop the review after seeing the method.
Comments for author File: 
Comments.pdf
Author Response
Suggestion 1: There is no novelty in this paper. Data and method were not present appropriately.
Comment 1: We have fully revised this paper (originally only over 5000 words, now it has been increased to over 15000 words). We have added winter simulations and highlighted our novelty by comparing the simulation results of summer and winter In addition, we use Air temperature, relative comfort, and wind speed to specifically illustrate the differences in thermal comfort situations. Our new abstract provides a specific overview of the main content of the article. It is obvious that it is completely different from what we started submitting. We really hope you can participate in the review again and we will try our best to meet your requirements.
“Abstract: Improving thermal comfort within the scope of urban roads is an important part of improving the livability of the entire city. We took Changsha city, which has typical hot summer and cold winter climate characteristics, as an example and selected a section of Zhutang West Road in the central urban area of Changsha for research. We use the microclimate simulation software ENVI-met to construct different scenario models to explore the impact of street trees and architectural features on the thermal comfort of street canyons in hot days and cold days. Based on the actual situation of the studied road section, the selection of street tree species is evergreen tree Cinnamomum camphora. We found that tall trees with large crowns and dense canopy have a significant cooling effect in both summer and winter. Therefore, it can improve the comfort of street canyon in summer and worsen it in winter. Street trees with small canopies and sparse leaves (including hedges) have less negative impact on the thermal comfort of street canyons in winter and are beneficial for wind protection, making them a good choice. In our study, demolishing some buildings to add open spaces can have a relatively positive impact on thermal comfort in winter, as it helps to reduce the cold shaded areas of buildings and weaken the strong winds generated by the effect of narrow. In summer, demolishing some buildings and adding open spaces can reduce the cool shaded areas of buildings and promote the flow of hot air towards the street canyons with more street trees. We call on future researchers to pay attention to the impact of improvement strategies on hot and cold weather at the same time when studying how to improve street canyon thermal comfort. Given that under hot and cold weather, the same improvement plan may have significantly different impacts. We believe that more research can be conducted to explore how to renovate urban street trees and buildings on both sides of roads to better meet the needs of summer and cold weather comfort.”
Suggestion 2: Please find the references that directly connected with PET and ENVI-met
I stop the review after seeing the method.
Comment 2: We have supplemented the formulas related to PET and introduced how to calculate PET in ENVI met. Please refer to page 9.
Comment 3: We can see that you have marked some sentences in the PDF document, but we have not found the corresponding modification suggestions. If we need to revise these sentences in the future, we will revise them carefully according to the requirements. We have created Tables 3 and 4 to introduce the situation of each model. Since this table mainly compares different characteristics, we have included tree species information in the article instead of listing them in the table. We have added LAD information for each model. Due to the different heights of buildings on both sides of the area we are studying and the same H/W values for all models, we did not input the H/W values for each model in the table. If you think the tables need to be further improved, we will revise the tables based on your guidance.
Round 2
Reviewer 1 Report
Comments and Suggestions for Authors
Thank you for considering my comments and thank you for your detailed answers.
However, the Manuscript is more like a technical report now than a scientific paper. I suggest you to shorten the Manuscript. Of course that does not mean deleting important information. Instead I recommend to use the appropriate terms which describe the situation/examination. E.g., I really appreciate the detailed descriptions such as in lines 350-353 but those can be shortened by writing you created a scatterplot of the measured and simulated values. And you need to mention only one time, that data procession was carried out in Excel.
I am still not comfortable mentioning studies without proper citation and use expressions like “some researchers”. E.g, in line 104 “A few studies on […]”, in line 107 “Many different methods […]” This leads to confusion. E.g. in lines 251-252: “Some researchers have verified the PET simulation results of ENVI- met are valid (Elraouf et al., 2022).” Elraouf et al. (2022) verified the PET simulation results of ENVI-met? Or Elraouf et al. (2022) stated that some other researchers verified the PET simulation results of ENVI-met? If the first one, then you should write Elraouf et al. (2022) have verified the PET simulation results of ENVI-met.
According to the template of the MDPI Journal Forests “The introduction should briefly place the study in a broad context and highlight why it is important. It should define the purpose of the work and its significance. The current state of the research field should be carefully reviewed and key publications cited. […]”. According to this, please try to make the Introduction more concise. E.g., without citations, the text in lines 104-120 does not seem to be appropriate for the Introduction. It seems to be more a discussion than an introduction.
Other example is in lines 348-349 “These three indicators have been used by a lot of researchers to analyze the errors of values of simulation in urban microclimate research.” This sentence is unnecessary in a scientific paper unless citations are added if this statement is relevant. If it is not, then it should be deleted.
The text between the lines 171-175 is confusing. Please can you rewrite it?
I will consider accepting the Manuscript after it will be rewritten in a more concise way.
Some minor issues:
in line 143: “canyons.In this”
on page 5: "by usin"
in lines 249 and 251: “ENVI met”, “ENVI- met”
Author Response
Comments and Suggestions for Authors
Thank you for considering my comments and thank you for your detailed answers.
Thank you again for the valuable suggestions.
Suggestion 1: However, the Manuscript is more like a technical report now than a scientific paper. I suggest you to shorten the Manuscript. Of course that does not mean deleting important information. Instead I recommend to use the appropriate terms which describe the situation/examination. E.g., I really appreciate the detailed descriptions such as in lines 350-353 but those can be shortened by writing you created a scatterplot of the measured and simulated values. And you need to mention only one time, that data procession was carried out in Excel.
Comment 1: I am sorry. I have rewritten the sentences to make it more concise.
“These three indicators have been widely used to analyze the accuracy of the simulation results in urban microclimate research (Tsoka et al., 2018; Zhu et al., 2023; Lam et al., 2021). We made scatterplots to analyze the errors between simulated values and measured values in excel. The R2 between the measured air temperature and the simulated air temperature was 0.97, the RMSE was 0.54, and the d was 0.9. R2 between measured humidity and simulated humidity was 0.96, RMSE was 1.63, and the d was 0.99.”
Suggestion 2: I am still not comfortable mentioning studies without proper citation and use expressions like “some researchers”. E.g, in line 104 “A few studies on […]”, in line 107 “Many different methods […]” This leads to confusion. E.g. in lines 251-252: “Some researchers have verified the PET simulation results of ENVI- met are valid (Elraouf et al., 2022).” Elraouf et al. (2022) verified the PET simulation results of ENVI-met? Or Elraouf et al. (2022) stated that some other researchers verified the PET simulation results of ENVI-met? If the first one, then you should write Elraouf et al. (2022) have verified the PET simulation results of ENVI-met.
Comment 2: I am so sorry for negating some details during the first-round revision. I have carefully checked the sentences to ensure the relevant citations appear.
I have changed the sentence in lines 251-252 to “Elraouf et al., (2022) have verified the PET simulation results of ENVI-met are valid in their study. This laid a solid foundation for future researchers to use ENVI-met to simulate PET values.”
Suggestion 3: According to the template of the MDPI Journal Forests “The introduction should briefly place the study in a broad context and highlight why it is important. It should define the purpose of the work and its significance. The current state of the research field should be carefully reviewed and key publications cited. […]”. According to this, please try to make the Introduction more concise. E.g., without citations, the text in lines 104-120 does not seem to be appropriate for the Introduction. It seems to be more a discussion than an introduction.
Comment 3: We have carefully revised the introduction part. We attempt to briefly place the study in a broad context in the review of literature part. We also tried to highlight the importance of the study during the review of literature. We have deleted the text in lines 104-120. We added sentences at the beginning of the fifth paragraph of the introduction. The fifth paragraph defined the purpose of the work and its significance.
The first paragraph of the introduction shows the research context. This tries to place the study in a broad context.
The second paragraph of the introduction introduce the current studies on the impact of composition of street greening and buildings on thermal comfort in street canyons in the summer through the review of relevant articles. This reviewed current state of the research field.
The third paragraph of the introduction reviewed relevant articles about the street trees and building configuration on street canyon thermal comfort. This reviewed current state of the research field.
The fourth paragraph shows the relevant research about winter thermal comfort. This also tries to reviewed current state of the research field.
The fifth paragraph define the purpose of the work and its significance.
Suggestion 4: Other example is in lines 348-349 “These three indicators have been used by a lot of researchers to analyze the errors of values of simulation in urban microclimate research.” This sentence is unnecessary in a scientific paper unless citations are added if this statement is relevant. If it is not, then it should be deleted.
Comment 4: I am so sorry for the negligence. I have added relevant references.
“These three indicators have been widely used to analyze the accuracy of the simulation results in urban microclimate research (Tsoka et al., 2018; Zhu et al., 2023; Lam et al., 2021).”
The three cited articles are reviews which can strongly support the argument.
Suggestion 5: The text between the lines 171-175 is confusing. Please can you rewrite it?
Comment 5: I am sorry. I have rewritten this part in the article.
“In China, the lunar definition for four seasons is widely used (Jiang et al., 2019). Based on the lunar defining of the four seasons, the beginning of spring, summer, autumn, and winter have been dated consistently on 3–4 February; 5-6 May; 7-8 August and 7-8 November of each year respectively during the last ten years (Ren et al., 2012). Thus, May 13, 2023 is a hot summer day and December 16, 2022 is a cold winter day.”
Suggestion 6: I will consider accepting the Manuscript after it will be rewritten in a more concise way.
Comment 6: I have revised the article to improve the language.
Some minor issues:
Suggestion 7: in line 143: “canyons.In this”
Comment 7: I am sorry. I have added space between “canyons” and “In this”
Suggestion 8: on page 5: "by usin"
Comment 8: I am sorry. I have added space between “by us” and “in”
Suggestion 9: in lines 249 and 251: “ENVI met”, “ENVI- met”
Comment 9: I am sorry. I correct the errors. I have used the right format “ENVI-met”.
Reviewer 2 Report
Comments and Suggestions for AuthorsThis article needs major revision. There are several concerns: (1) The study of outdoor human thermal comfort requires the analysis of air temperature, humidity, wind speed, and mean radiant temperature. This study analyzed air temperature, relative humidity, and wind speed, but did not include mean radiant temperature which is the most effective microclimatic factor on human thermal comfort, especially in outdoor areas. This study needs the mean radiant temperature analysis. (2) The manuscript is too long. From pages 18 to 24, the microclimatic factors do not need to be shown. The differences of air temperature, relative humidity, and wind speed except the model 6 were very small, and the contents could be included to explain the difference of PET among the six models. (3) The manuscript requires much modification. The section of references is not listed by authors’ names. The expression of scientific and proper units should be used adequately.
The minor concerns are listed below:
1. In the abstract, write “Cinnamomum camphora” in italic style because it is a scientific plant name.
2. Fix the unit of leaf area density to m2m-3, not m3/m2.
3. In line 258 of page 7, please erase “2.3”.
4. Please input the information of canopy width and trunk height in page 8.
5. Please indicate the version of ENVI-met.
6. In tables, change times to hour and minute, e.g. 9:00:01 to 9:00.
7. In line 406 of page 14, erase “)” after Figure 4.
8. In the first paragraph of page 18, the contents are understandable, but it is too long and unclear. Please explain in fewer sentences.
9. Throughout the entire manuscript, please identify what kind of temperature is indicated in the sentences. Change all temperatures to specific temperatures such as air temperature, surface temperature, or mean radiant temperature.
10. Please use scientific units, e.g. m/s to ms-1.
11. Please use only last names for references, i.e. Rodriguez Algeciras and Matzarakis (2016) in line 689 of page 23.
12. The unit of wind speed is ms-1, not %, in line 822 of page 29.
Comments on the Quality of English LanguageMainly the manuscript was written properly in English. However, the sentences were too long and many places had mistakes. Please express the authors' thoughts clearly and shortly.
Author Response
Comments and Suggestions for Authors
Suggestion 1: This article needs major revision. There are several concerns: (1) The study of outdoor human thermal comfort requires the analysis of air temperature, humidity, wind speed, and mean radiant temperature. This study analyzed air temperature, relative humidity, and wind speed, but did not include mean radiant temperature which is the most effective microclimatic factor on human thermal comfort, especially in outdoor areas. This study needs the mean radiant temperature analysis.
Comment 1: Thanks again for your valuable suggestions. We have carefully revised the article. I have added the mean radiant temperature analysis for each model on the hot day and the cold day. Based on your suggestion, I did not form the mean radiant temperature analysis as an induvial part. I used mean radiant temperature as an explanation of PET. You can find the mean radiant temperature analysis at the corresponding PET analysis parts.
Suggestion 2: (2) The manuscript is too long. From pages 18 to 24, the microclimatic factors do not need to be shown. The differences of air temperature, relative humidity, and wind speed except the model 6 were very small, and the contents could be included to explain the difference of PET among the six models.
Comment 2: I have deleted all figures and tables of microclimatic factors (air temperature, relative humidity, and wind speed). They do not form individual part anymore. I have incorporate them (including mean radiant temperature) in the corresponding PET analysis part in a concise way.
Suggestion 3: (3) The manuscript requires much modification. The section of references is not listed by authors’ names. The expression of scientific and proper units should be used adequately.
Comment 3: We have carefully revised the whole article not only in the content but also in the expression. I have list reference by the authors’ name alphabetical. I have also checked the whole article to ensure the intext citation in right form.
The minor concerns are listed below:
Suggestion 4: 1. In the abstract, write “Cinnamomum camphora” in italic style because it is a scientific plant name.
Comment 4: I am so sorry. I have changed all scientific plant names to italic style.
Suggestion 5: 2. Fix the unit of leaf area density to m2m-3, not m3/m2.
Comment 5: I am so sorry. I have changed all m2m-3 to m3/m2.
Suggestion 6: 3. In line 258 of page 7, please erase “2.3”.
Comment 6: I am sorry for the negligence. I have erased “2.3”.
Suggestion 7: 4. Please input the information of canopy width and trunk height in page 8.
Comment 7: I have added canopy width and trunk height information in the last few lines of the long paragraph on page eight.
“The canopy width of all 15-meter-high street trees is set to 9 meters, and the trunk height is set to 4 meters. All 5-meter-high street trees have a uniform canopy width of 3 meters and a trunk height of 1 meter.”
Suggestion 8: 5. Please indicate the version of ENVI-met.
Comment 8: We indicated the version of ENVI-met in the abstract and the first time it appear on the main body part (In 2.1 Data collection and selection of thermal comfort index part).
“We use the microclimate simulation software ENVI-met 5.5.1 to construct different scenario models to explore the impact of street trees and architectural features on the thermal comfort of street canyons in hot days and cold days.”
“We used ENVI-met version 5.5.1 to conduct the simulation study.”
Suggestion 9: 6. In tables, change times to hour and minute, e.g. 9:00:01 to 9:00.
Comment 9: We have changed times to hour and minute in tables. We also updated the relevant figures.
Suggestion 10: 7. In line 406 of page 14, erase “)” after Figure 4.
Comment 10: I am sorry. I have erased “)” after Figure 4.
Suggestion 11: 8. In the first paragraph of page 18, the contents are understandable, but it is too long and unclear. Please explain in fewer sentences.
Comment 11: We are sorry. We have added the analysis related to mean radiant temperature, air temperature, relative humidity, and wind speed to the PET analysis section. The first paragraph of page 18 has been deleted. The relevant contents have been included in PET analysis in a concise way.
Suggestion 12: 9. Throughout the entire manuscript, please identify what kind of temperature is indicated in the sentences. Change all temperatures to specific temperatures such as air temperature, surface temperature, or mean radiant temperature.
Comment 12: We are so sorry. We have carefully checked the whole article and specify what kind of temperature is indicated in the sentences.
Suggestion 13: 10. Please use scientific units, e.g. m/s to ms-1.
Comment 13: I have corrected all relevant issues. I think we use scientific units in the whole article now.
Suggestion 14: 11. Please use only last names for references, i.e. Rodriguez Algeciras and Matzarakis (2016) in line 689 of page 23.
Comment 14: I think Rodríguez Algeciras is his surname based on the article information page of the journal and Web of Science (Quantification of thermal bioclimate for the management of urban design in Mediterranean climate of Barcelona, Spain DOI: 10.1007/s00484-015-1121-8). Thanks for your reminding. I have checked the whole article to ensure we use only last names for references in the article.
Suggestion 15: 12. The unit of wind speed is ms-1, not %, in line 822 of page 29.
Comment 15: The line 822 of page 29 has been deleted. We have added the analysis related to mean radiant temperature, air temperature, relative humidity, and wind speed to the PET analysis section. They do not form individual parts anymore. We have carefully checked to avoid the same mistakes in the new PET analysis section.
Comments on the Quality of English Language
Suggestion 16: Mainly the manuscript was written properly in English. However, the sentences were too long and many places had mistakes. Please express the authors' thoughts clearly and shortly.
Comment 16: We have revised the article carefully especially the language.
Round 3
Reviewer 1 Report
Comments and Suggestions for Authors
Thank you for your answers and considering my suggestions. The Manuscript (hereinafter referred to the MS) certainly improved, it was shortened significantly. The methodology and the results are presented more clearly.
Please find my questions and comments below, where the numbers of the lines correspond to the pdf version of the MS which includes track-changes.
(1) Please explain why Dec. 16 was selected. Is it a typical cold winter day? The daily course of the temperature does not seem typical since temperature reaches its maximum value in the morning.
(2) Aren't the results referenced in lines 154-159 dependent on the wind direction and wind speed?
(3) What is the meaning of “good summer and winter thermal comfort” in lines 223-224?
(4) Please revise the sentence in lines 240-247. It is difficult to understand in its current form.
(5) According to line 364, calculations were done for a 35-year-old man. What is his body weight? How the terms of Eq. 1., i.e., metabolic rate, net radiation of the body were calculated for this man?
(6) In line 375 the phrase “thophoto map” is not familiar to me. Please could you explain it?
(7) It is unclear why the same six models were not used for the summer and the winter days. According to line 392 ”When the LAD is 0.825 m^2*^m-3, the canopy of the street tree is dense enough.” Please explain for what is the canopy dense enough? Furthermore, in Figs. 2 and 3 I can’t notice any differences between the plots of Model 1 and Model 2. Are there any visible differences between them?
(8) Eq. 4 seems to be incorrect. Please check it.
(9) Please explain what is the meaning of ”a good street canyon layout” in the conclusion (in line 1198)?
(10) Please could you provide error analysis for the cold winter day also?
(11) There are some misspellings or missing spaces in lines 234, 257, 306, and 549. Please revise those.”
(12) In line 372 there is a missing break before the chapter title.
(13) In line 317 the format of the date differs from other dates of the MS.
(14) Please add to line 241 what the abbreviation LAD stands for.
(15) Please define aspect ratio at its first occurrence (in line 124).
Author Response
Suggestion 1: Thank you for your answers and considering my suggestions. The Manuscript (hereinafter referred to the MS) certainly improved, it was shortened significantly. The methodology and the results are presented more clearly.
Please find my questions and comments below, where the numbers of the lines correspond to the pdf version of the MS which includes track-changes.
Comment 1: Thanks for your valuable guidance. We have carefully revised the whole article based on your suggestion
Suggestion 2: (1) Please explain why Dec. 16 was selected. Is it a typical cold winter day? The daily course of the temperature does not seem typical since temperature reaches its maximum value in the morning.
Comment 2: Our research aims to explore the different effects of road greening landscape patterns (with evergreen tree species) on the thermal comfort of street canyons on hot and cold days. Changsha is one of the representative cities in hot summer and cold winter regions of China. Selecting representative hot and cold days in Changsha can be used to explore this topic. The representative winter day we refer to is only the cold winter day. Although the highest temperature throughout the day in winter often occurs between 12:00 and 15:00. From my personal perspective, as long as the air temperature during the whole day is low, even If the highest temperature occurs around 10:00 or 11:00, these days can also be representative cold winter day. This is because we think this does not affect the research objectives. The air temperature was all below 9 ℃ from 10:00 to 18:00 on December 16, 2022. The air temperature is below the comfortable range of 12-22 ℃ in winter. In this case, we need to consider how to increase the air temperature of the street canyon in order to improve the thermal comfort. As for why the highest temperature occurred at 10:00, I believe it is due to two reasons. Firstly, from December 15, 2022 to December 17, 2022, the temperature experienced a sudden drop and then a rapid increase in Changsha (according to historical temperature data available for reference https://lishi.tianqi.com/changsha/202212.html , On December 15, 2022, the highest temperature was 14 ℃ and the lowest temperature was 6 ℃; On December 16, 2022, the highest temperature was 7 ℃ and the lowest temperature was 3 ℃; On December 17, 2022, the highest temperature was 10 ℃ and the lowest temperature was -3 ℃. By the way, our meteorological data collection site is different from the meteorological data collection site of the website which provide historical air temperature data. Therefore, there are also certain differences in the highest and lowest temperatures between the mereological data provided by the website and our metrological data). Secondly, I still remember that the weather was relatively sunny in the early morning. By 9 to 10 o'clock in the morning, the weather was gradually turning cloudy and the wind speed was high. Because my measurement started at 10 o'clock, I do not have data from 7 to 9 o'clock that day. I believe it is highly likely that the temperature is gradually increasing from 7 to 9. Because we believe that the overall cold temperature from 10:00 to 18:00 on December 16, 2022 can represent a cold winter, we chose the measured data from this time period for simulation research. In addition, I think the highest temperature occurred around 10 or 11 is not rare during cloudy and windy day. For example, the highest temperature occurred at 9 o clock in Feng Xian district, Shanghai, China on 30 September 2023 (We found this from the official daily release data, so the information is undoubtedly accurate).
I have explained this at the last paragraph of the 2.1 part of the article as below
“According to relevant experiments in various countries, the comfortable air temperature for people in summer is between 19 and 24 ℃ (The central People’s Government of the people’s Republic of China, 2007; China Meteorological Administration, 2011). The air temperature we measured during May 13, 2023 from 8:00 to 18:00 was mostly higher than the highest comfortable air temperature for the human body 24 ℃. The weather is sunny and the air temperature is hot on May 13, 2023. It is necessary to fully utilize the cooling effect of road green spaces to effectively improve the thermal comfort of the street canyons. This day belongs to a representative hot summer day. Many researchers have pointed out that the comfortable air temperature range for winter is between 12 and 22 ℃ (The central People’s Government of the people’s Republic of China, 2007; China Meteorological Administration, 2011). The air temperature we measured from 10:00 to 18:00 on December 16, 2022 is below the minimum comfortable air temperature 12 ℃. The morning was relatively sunny, and the noon and afternoon were cloudy and windy. This day belongs to a representative cold winter day. In this case, measures to increase the air temperature of the street canyon can enhance the comfort of the street canyon.”
Suggestion 3: (2) Aren't the results referenced in lines 154-159 dependent on the wind direction and wind speed?
Comment 3: I have read the article again (Yang, Y.J.; Zhou, D.A.; Gao, W.J.; Zhang, Z.H.; Chen, W.; Peng, W.C.Y. Simulation on the impacts of the street tree pattern on built summer thermal comfort in cold region of China. Sustainable Cities and Society 2018, 37, 563-580, 1240 doi:10.1016/j.scs.2017.09.033.). They studied the thermal comfort of the urban street canyons of Xi'an City, China. They pointed out that the urban street canyon area in Xi'an is generally narrow. The influence of wind direction and speed on the thermal comfort of street canyons is relatively small. The shadow area generated by buildings and trees caused the main difference between different models. The shadows of buildings and trees appear in the southwest or west, or northwest of them in the morning (different dates have different locations for the first appearance of building shadows in the morning). From then on, it gradually moved to its true north position (reaching its true north at noon). After the shadow reach the true north of the building, it gradually moved and appeared in the northeast, east, or southeast of the building in the evening (the location where the shadow of the building disappeared in the evening varies on different dates). East-west streets and north-south streets are influenced differently by sunshine, architectural and tree shadows. The most suitable buildings and trees layout for the thermal comfort of the east-west street is different from the most suitable buildings and trees layout for the thermal comfort of north-south street.
I have rewritten the sentences in lines 154-159. I think I give more detailed explanation about the Yang et al., (2018)’s study. The rewritten sentences can be seen below as well as the corresponding position at the second part of the introduction.
“Yang et al. (2018) found that if the street canyon is narrow, wind has weak impact on the thermal comfort. In this case, the shadows of buildings and trees can have more significant impact on the thermal comfort. Under the same lighting conditions, the shadow generated by buildings and trees in east-west streets has a different effect on the thermal comfort of street canyons compared to the shadow generated by buildings and trees in north-south streets. This is mainly because the city they studied, Xi'an is located in the northern hemisphere, north of the Tropic of Cancer. Affected by the specific location of shadows generated by buildings and trees at different times throughout the day, the buildings and trees on the south side of the street can play a quite active role on improving the thermal comfort of the street canyon during many different times of the day especially around noon. Thus, on the east-west streets, planting street trees near buildings had the best effect for the improvement of thermal comfort in street canyons. For north-south streets, the thermal comfort is better if the trees were planted at the middle of one side of the street. This is mainly because it can better utilize the buildings and trees shadow to improve the thermal comfort of the street canyon during many different times of the day [11].”
Suggestion 4: (3) What is the meaning of “good summer and winter thermal comfort” in lines 223-224?
Comment 4:
I am so sorry. This means “An improvement plan that is beneficial for improving the summer thermal comfort of the street canyon through measures such as building shadows and the transpiration effect of street trees, while also improving the winter thermal comfort of the street canyon through measures like the use of buildings and street trees wind blocking effects.”
I have rewritten the sentence as below.
“This indicates that not only the summer thermal comfort can be improved by optimizing the spatial configuration of the street canyon but also the winter thermal comfort can be improved by optimizing the spatial configuration of the street canyon. Due to the impossibility of implementing two different renovation plans simultaneously in the same street canyon area. In this case, an improvement plan that is beneficial for improving the summer thermal comfort of the street canyon through measures such as building shadows and the transpiration effect of street trees, while also improving the winter thermal comfort of the street canyon through measures like the use of buildings and street trees wind blocking effects, is very important.”
Suggestion 5: (4) Please revise the sentence in lines 240-247. It is difficult to understand in its current form.
Comment 5: We are sorry. I have rewritten the sentences. You can see the revised sentence below as well as the last some sentences of the last paragraph of the introduction.
“We will focus on the impact of street tree quantity, height, canopy features (LAD, crown width, crown height and canopy density) on the thermal comfort of the street canyon during hot and cold days. In addition, we will also consider whether the impact of street trees on the thermal comfort of the street canyon can be different under different building features, wind speed and wind direction).”
Suggestion 6: (5) According to line 364, calculations were done for a 35-year-old man. What is his body weight? How the terms of Eq. 1., i.e., metabolic rate, net radiation of the body were calculated for this man?
Comment 6: I am sorry. I have added the body weight and height information (heigh: 1.75 m, weight: 75 kg).
“The PET values for May 13th 2023 were calculated based on the default male, summer clothing (Male, 35 years old, heigh: 1.75 m, weight: 75 kg, outdoor: 0.50 clo, pre. Speed: 1.34 ms-1, total metabolic rate: 86.21 W/m2). The PET value calculation for December 16, 2022 is based on the default male, average clothing (Male, 35 years old, heigh: 1.75 m, weight: 75 kg, Outdoor: 0.90 clo, pre. Speed: 1.34 ms-1, total metabolic rate: 86.21 W/m2).”
We referred to the standard setting in ENVI-met software, which is total metabolic rate: 86.21 W/m2. This is the metabolic rate determined based on ISO 7730 Ergonomics of the thermal environment for 35 years old, 1.75 meters, 75kg, male standard conditions I have supplemented the relevant total metabolic rate information in the article.
I have added two new formula and relevant explanations below equation 1. By combining the following formulas (2) and (3) with formula (1), the core temperature of the human body, skin surface temperature, and clothing surface temperature can be calculated. These three indicators are the main indicators that determine the thermal sensation of the human body. After knowing these three indicators, people can know the human thermal sensation further ( Krüger et al., 2017; Ji et al., 2022).
Suggestion 7: (6) In line 375 the phrase “thophoto map” is not familiar to me. Please could you explain it?
Comment 7: I am so sorry for the negligence. It should be “orthograph”. I have revised this in the article.
In addition, I have added explanation for this.
“We spliced the pictures with DJI Terra to form an orthograph. This can correct geometric deformation of the pictures caused by sensors, external orientation elements, and terrain fluctuations. The shape of orthograph is consistent with the actual situation. The scale of different areas of the orthophoto map is consistent. The relevant orientations of each part in the orthophoto remain unchanged（Lin and Cang, 2006; Liu et al., 2022）.”
Suggestion 8: (7) It is unclear why the same six models were not used for the summer and the winter days.
Comment 8: The model 1-6 are all simulated based on the actual meteorological conditions of the study area. The meteorological condition (like air temperature, relative humidity, wind speed, and wind direction and so on) is different between May 13, 2023 and December 16, 2022. The simulated meteorological condition of Model 1 in May 13, 2023 is different from the simulated meteorological condition of Model 1 in December 16, 2022. The meteorological condition is the only difference between Model 1 simulated on May 13th, 2023 and December 16th, 2022. Models 2-5 are also the same, with only different meteorological conditions simulated during May 13, 2023, and December 16, 2022, respectively. The composition and configuration of buildings and plants in the same model are identical. The wind direction is set as 90 ° for the simulation of model 6 in summer day. The wind direction is set as 180 ° for the simulation of model 6 in winter day. Model 6 mainly explores the different effects of changing wind direction conditions on the thermal comfort of street canyon. We believed that setting more different wind directions would be more conducive to the development of research. This is because if we compare the simulated model 1 and 6 based on the summer or winter day meteorological condition, the wind direction is the only variable.
We have added an explanation at the end of the last but one paragraph of 2.2 Data collection and selection of thermal comfort index part. “Model 6 was set different wind directions in summer and winter days. This is beneficial for the comparison of the thermal comfort of the street canyon under different wind direction.”
Suggestion 9: According to line 392 ”When the LAD is 0.825 m^2*^m-3, the canopy of the street tree is dense enough.” Please explain for what is the canopy dense enough?
Comment 9: We are sorry. We have rewritten the paragraph to explain why is the canopy dense enough.
You can see this below as well as the third paragraph of the 2.3 part.
“Xue and Li (2017) pointed out that the LADs of broadleaf trees usually range from 0.2 to 1.1 m2m-3。The studies of Yun et al., (2020), Katul et al., (2004), Chen et al., (2022), Zhou et al., (2020), Zhao et al.,(2014), Wang et al., (2018), Li (2012) show the LADs of different trees are within this range. Among these studies， Zhao et al.,(2014); Wang et al., (2018); Li (2012) explored the canopy features of Cinnamomum camphora or Platanus hispanica. For some studies which only provide LAI values, we refer to Lalic et al. (2004) to determine LAD based on LAI. Based on measured data and reference to other relevant studies [32-34], when the LAD of the street tree is 0.225 m2m-3, the canopy of the street tree is relatively sparse. Referring to the common range of broadleaf trees LAD values pointed out by Xue and Li (2017), and combined with our actual measurement of street tree LAI in different areas of Changsha, we ultimately determined that the LAD of dense street tree model is uniformly set as 0.825m2m-3. We built a model 2, which has the same feature as model 1 except the LAD of street trees on both sides of the road is 0.825 m2m-3.”
Suggestion 10: Furthermore, in Figs. 2 and 3 I can’t notice any differences between the plots of Model 1 and Model 2. Are there any visible differences between them?
Comment 10: Yeah, there are visible difference between them. Please see the top right of the plots of model 1 and model 2. The plot of model 1 shows the words “LAD = 0.225 m2m-3 ”. The plot of model 2 shows the words “LAD = 0.825 m2m-3 ”.
Suggestion 11: (8) Eq. 4 seems to be incorrect. Please check it.
Comment 11: I am still unsure which part of Eq.4 you are referring to is incorrect. I have changed Eq.4 to the same formula expression as Tsoka et al., (2018). (The specific information of the article is Tsoka, S.; Tsikaloudaki, A.; Theodosiou, T. Analyzing the ENVI met microclimate model's performance and assessing cool materials and urban vegetation applications – A review. Sustainable Cities and Society 2018, 43, 55-76, doi: https://doi.org/10.1016/j.scs.2018.08.009. ）For example, when writing the denominator, I no longer use "-" but instead use "/". I have removed the original “ (0 d 1)”. Tsoka et al. (2018) did not write this. I originally wrote this based on other articles, so I deleted it. I have changed from summary with subscript to summary with limit. I don't know if the error you mean is 'Pi - Oi' or 'Oi - Pi'. This does have a different order in some different articles. But after taking the square, the values are the same. In addition, I have also made adjustments to Eq.2 and 3 so that their fractions and other symbols match Eq 4.
We referred Willmott et al., （1981）（Willmott CJ. 1981. On the validation of models. Physical Geography2: 184 – 194）for index of agreement calculation. We have checked the equation in our article and it is consistent with Willmott et al., （1981）. Willmott et al., （1981）is still widely used until now.
Suggestion 12: (9) Please explain what is the meaning of ”a good street canyon layout” in the conclusion (in line 1198)?
Comment 12: I am sorry. I have rewritten the sentence in the last paragraph of the conclusion.
“Thus, we argue that a good street canyon renovation plan for the improvement of thermal comfort should not be one that can produce a significant improvement in thermal comfort in one season but can have a significant negative impact on street canyon thermal comfort in other seasons. The renovation plan needs to consider its impact on the street canyon throughout the year and demonstrate that the benefits of the renovation outweigh the drawbacks.”
Suggestion 13: (10) Please could you provide error analysis for the cold winter day also?
Comment 13: I am so sorry. The measurement point where we measured the measured the meteorological data on May 13, 2023 is located in the research area of Zhutang West Road. We can directly conduct error analysis based on the measured temperature and humidity data of each hour and the corresponding simulated data. The data we measured on December 16, 2022 was taken from another location around the study area (this data is only used by this research, and we will strictly follow the requirements to avoid data reuse or misuse). We use this measured data to represent the meteorological data of the big area where the research site is also located. We have explained this in the 2.2 part of the article. Because researchers often study urban microclimate in a wide range, many researchers use a single data to control errors for meteorological data located in multiple different small areas within a large area, such as Sui et al.,(2023), Salameh and Touqan(2022), Peng et al., (2013) . Because we did not anticipate the error analysis of both summer and winter, we did not create a model for the winter measurement area at that time. The rationality of ENVI-met has been proven by over 3000 research. Many researchers only selected one simulation period for error analysis. So we would like to first ask if we can only use the error analysis during the summer simulation period. Our randomly selected summer simulations have proven that the simulation error is reasonable. If you still think that winter error analysis is necessary, I hope you can give us more time for revision. We only have four days for revision this time. Due to time constraints, it is difficult to complete the winter error analysis.
Sui, Q.; Jia, H.; Zhao, M.; Zhou, Y.; Fan, L. Quantitative Evaluation of Ecosystem Services of Urban Street Trees: A Case Study of Shengjing Historical and Cultural Block in Shenyang, China. Sustainability 2023, 15, 2532. https://doi.org/10.3390/su15032532
Salameh, M.; Touqan, B. Traditional Passive Design Solutions as a Key Factor for Sustainable Modern Urban Designs in the Hot, Arid Climate of the United Arab Emirates. Buildings 2022, 12, 1811. https://doi.org/10.3390/buildings12111811
Peng, L.L.H.; Jim, C.Y. Green-Roof Effects on Neighborhood Microclimate and Human Thermal Sensation. Energies 2013, 6, 598-618. https://doi.org/10.3390/en6020598
Suggestion 14: (11) There are some misspellings or missing spaces in lines 234, 257, 306, and 549. Please revise those.”
Comment 14: We are sorry. We have corrected these errors.
Line 234: “Their strategies may not be good from the whole year's perspective. we attempted to study the impacts of street tree configuration…”
Line 257: “According to Köppen-Geiger climate classification updated by Beck et al. (2018), Changsha is located”
Line 306: “We used the average wind direction and speed throughout…”
Line 549: “…the impacts of street greening on street canyons during both hot and cold days. This can help to…”
Suggestion 15: (12) In line 372 there is a missing break before the chapter title.
Comment 15: I have made the chapter title “2.2 Model building and simulation analysis” begin with a new line.
By the way, this kind of error can be caused when the assistant editor changed the tracking changes of the article from no markup to all markup or all markup to no markup. Because I do not know he will choose all markup or no markup next time. I am not able to ensure similar error like this will not happen again. Anyway, I will try my best to avoid this.
Suggestion 16: (13) In line 317 the format of the date differs from other dates of the MS.
Comment 16: I have unified the format of the date of the whole article.
They are written as “May 13, 2023” and “December 16, 2022”
Suggestion 17: (14) Please add to line 241 what the abbreviation LAD stands for.
Comment 17: I have added the definition in the last paragraph of the introduction part.
“LAD is defined as the total one-sided leaf area per unit volume (Chen et al., 2006; Rouzbeh et al., 2019; Lalic et al., 2004).”
Suggestion 18: (15) Please define aspect ratio at its first occurrence (in line 124).
Comment 18: I am sorry. I have defined the aspect ratio at its first occurrence now. “Cui et al., (2023) found that if the street orientation and vegetation distribution are the same, when the aspect ratio (a ratio of building height to street width) (Vardoulakis et al., 2003; Zheng et al., 2022) is 0.9, the thermal comfort of the street canyon is the best.”
Please ignore “(Vardoulakis et al., 2003; Zheng et al., 2022)” above. I know it is not MDPI style at the moment. Currently, the reference style is a mix of Harvard reference style and MDPI style in the article (MDPI allow the use of other citation style during revision). If the article can be accepted, I will change all citations to MDPI numerical style.
