Effects of Road Components and Roadside Vegetation on Temperature Reduction in Seoul Considering Air, Wet-Bulb Globe, and Surface Temperatures

Round 1

Reviewer 1 Report

The study presents observations of temperature for roads with different green covers. The experimental design is simple yet robust.  I do have some clarifications:

(1) Fig. 1, it would be helpful to draw a box in Fig 1a on the boundaries of Fig 1b

(2) Fig. 2 - add site number (from fig 1) to the images for easier readability, also, include dimensions/width of the illustrations in Fig 2 e-h (width of road) 

(3) it can be noticed from fig. 2 that the roads have 3-4 story buildings on the side or both sides, does the shadow cast by the buildings at certain times of the day not affect the measurements? (in addition to the effect of trees?) I believe this should be added (1 or 2 sentences) in the discussion.

(4) It is not clear where the KMA measurements were done. It would be helpful to include the location in Fig. 1

(5) last paragraph of sec.2.2 states that there were 3 measuring periods, but most data shows continuous 07 to 21H measurements. I assume that the authors were referring to the thermal imager data only? If so, please rephrase to make this clear.

(6) Figure 5, are these 4 plots taken on different days?

(7) sec.3.3, thermal images were averaged - can you further explain how the averaging was done (can be included in the methodology section)?

Overall, I think this study is interesting and useful for policymakers/urban planners, I recommend acceptance after minor revisions.

 

Author Response

Thank you for your comments which improve the quality of my manuscript and readability. I tried my best to apply all of your comments to the script and explain the changes.
Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The subject is interesting and has been addressed by a number of recent papers, that however aTherefore, although the subject has considerable interestre not mentioned in the references. The experiments seem well planned and the methodology appropriated. However the way in which results in sections 3 (results and discussion)  and the section 4  are not acceptable.  Therefore, although the subject has considerable interest and the study is well done, sections 3 and 4 need to be improved before publication (see attached file with more comments).

Comments for author File: Comments.doc

Author Response

Thank you for your comments which improve the quality of my manuscript and readability. I tried my best to apply all of your comments to the script and explain the changes. I also attached the revised version of the manuscript, where you can find out all the changes with red color sentences.

Please find the attached files.

Author Response File: Author Response.pdf

Reviewer 3 Report

The author noted that street trees and vegetation in the median strip can prevent temperature rise and contribute to the reduction of urban temperatures. The integrated effects of radiation combined with wind, surface temperature, roadside air temperature, and wet bulb temperature (WBGT) were used to describe urban temperature changes. The author emphasizes that more roadside trees, median strip planting, taller trees, and denser vegetation along roads can contribute to more significant reductions in roadside temperatures and improved urban climate.

I agree with the findings that these are some possible ways, also, to eliminate the urban heat island (UHI) effect. I found this study interesting and after minor queries recommend it for publication.

Please elaborate on the importance of using multiple temperature indices (e.g. WBGT) versus using air or surface temperature alone. The advantages and disadvantages of the two different approaches should be presented in the results and summary section.

 Were these roads built in four different locations with the same materials?

 Please provide clear photographs. Use a high-resolution camera to take photos.

Author Response

Thank you for your comments which improve the quality of my manuscript and readability. I tried my best to apply all of your comments to the manuscript and explain the changes.

• However the way in which results in sections 3 (results and discussion) are presented is not adequate. The same importance is given to the temperature values obtained (which have relatively little value) than to the results of the intercomparison between them (which are the relevant points of the study). Moreover, the same attention is paid to results where the differences were assessed statistically as to those where the differences found no statistical support.  And the same comments are valid in the case of the conclusions, where the paragraphs 2 and 3 need a new drafting. Therefore, although the subject has considerable interest, and the study is well done, the drafting of sections 3 and 4 need to be improved before publication.

I tried to rewrite some of the manuscripts for improvement and better understanding. Please see the revised manuscript attached.

(2) Similar studies have appeared recently in other MDPI  journals, as Land or IJERPH, but are not mentioned.

I added more studies reviews in the introduction. There are many similar studies but I chose some of them which focus on temperature change of roads and ambient environment.

(3) Images in Figure 3 a and b need some improvements.

I changed the photos in Figure 3.

(4) In figure 6, comparison of roadside air temperature, it reads it reads ‘T(r)₁ vs T(r)4’ in the header,

and T(ra)₁ , T(ra)₄  in the type of line specification.

Deleted the header of all graphs e.g. ‘T(r)₁ vs T(r)4’

- In section 3.1 , lines 163-165 need new drafting

The results of the F- and t-tests show that the mean and the variances between sites 1 and 4 were different, and those between sites 2 and 4 were too (Table 2). They were the same between sites 3 and 4. These indicate that the  at site 1 and 2 are significantly higher than site 4, while that at 3 is the same at site 4. It indicates that roadside trees and a vegetated median led to significantly lower roadside temperatures at site 4.

- In section 3.2 , lines 194-200 need also some new writing

I deleted them because they were redundant with the content of the table.

- In line 217-218, the sentence ‘The mean differences ..are not significant’ is redundant, it is better expressed in the next sentences.

I deleted the sentence In line 217-218.

- The second and third paragraph of the conclusions (lines 280-302) need to be redrafted.

I rewrote those paragraphs as following.

The results showed clear temperature differences between the air temperature, , collected from meteorological stations, and the roadside air temperature The  values showed similar patterns for all four sites, whereas  decreased from site 1 to site 4, implying that an increase in the number of roadside trees and median vegetation reduced the roadside temperature. was typically higher than  before 18:00, then decreased to the same as . The  patterns were clearly different from those of  at all sites. The mean of (32.0 °C) was significantly higher than the mean (25.0 °C), and the results of the t-test showed that the mean values of and were significantly different at all sites.  appeared to be more sensitive to road characteristics, and was higher than  particularly between 13:00 and 15:00. The analysis of surface temperatures, , showed that the mean  of each site on the roadway was 35.4 °C at sites 1 and 2, 31.8 °C at site 3, and 30 °C at site 4. The  of sites 1 to 4 on the sidewalk was 37.4, 32.3, 34.2, and 30.1 °C, respectively. Site 4 also showed the smallest differences in roadway  throughout the day, with an increase of 9 °C from morning to afternoon, and a 7.4 °C decrease from afternoon to evening.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The quality of the presentation has been considerably improved by the author. 

Some minor problems still remain, as for instance,

1-  Please check the english of line 194

2- line 217, please replace 'are not different' by 'are not significantly different'

3- line 278   redraft the sentence  ' The  two tailed t-test values ..were all 0.0'.

    I suggest ' the two tailed t-test rejected the null hypothtse (the T(st) mean

     being the same) with a negligeable probability of error'.

4- Lines 314-324 present again results, not conclusions. If I were tha author, I would delete this paragraph. It adds nothing to the paper, and make the conclusions too long.  

Author Response

Thank you for your kind, valuable and detailed comments. I learned the way an explanation about statistical results, which contributes to improving my manuscript.

1- Please check the English of line 194

Yes. I rewrote the sentences for clear clarification as follows.

As shown in Table 2, the results from F-test reject the null hypothesis (the  variance being the same) between sites 1 and 4, and also between sites 2 and 4. However, the P-value for sites 3 and 4 fails to reject the N0. The results of t-test show the similar patterns between sites.

 

2- line 217, please replace 'are not different' by 'are not significantly different'

Yes, I replaced the words.

 

3- line 278 redraft the sentence ' The two tailed t-test values ..were all 0.0'. I suggest ' the two tailed t-test rejected the null hypothtse (the T(st) mean being the same) with a negligeable probability of error'.

Yes. I rewrote the sentences for clear clarification as follows.

The results of two-tailed t-tests with heterogeneous variance show that the two tailed t-test rejected the null hypothesis (the  mean being the same) with a negligible probability of error.

 

4- Lines 314-324 present again results, not conclusions. If I were an author, I would delete this paragraph. It adds nothing to the paper, and make the conclusions too long.

Thank you. I deleted the paragraph.