Shelter Effect of Pedestrian Wind behind Row Trees in a Line Arrangement

Round 1

Reviewer 1 Report

Trees have a wide ecosystem supply, they are not only wind sheltering and landscape beautifying tools for landscape planners and residents or landscape users. Wind system modification, wind flow control or mitigation might be important issues in urban or landscape planning.  Studying the wind flow effects of green areas with valuable tree canopy has a long research history and the results helped planning for wind protection, against snowdrift, improving the usability of residential or recreational areas, etc. 

Here, in this study, no detailed research question or aims are given, especially no idea according to the possible use of the model's results. As far as the method, the model is based on a set of different tree row situations given the plantation distance and crown and the height. Theoretically, the model is usable for helping the tree allée design with a special aspect on wind protection.  The model results are informative for wind speed reduction and the downstream effects, the distances behind the trees.

The structure and proportions of the paper are not balanced. Introduction and Method parts are detailed though some exemplary models could also be mentioned and introduced, as forests and other greenery, or tree canopy types in previous wind flow models. 

Unfortunately, Discussion and Conclusion parts do not serve well the interested professionals. Practically, the conclusion is more a discussion of the results, and in this form a repetition, and not the explanation of the overall importance of the research. No idea is given about the questions risen by the research and how the model and the model-based research could be developed for better adaptability in landscape planning.

 

Author Response

Please see the attachment file. Thank you very much.

Author Response File: Author Response.pdf

Reviewer 2 Report

Urban forests are the more hot issue of variable aspect with expected function recently, particularly climate change, global warming, and air pollution.
This article is an appropriate theme for urban green area management and corresponds with global issues of carbon absorption, air pollution, and human health.
The simulated model in the article is unique and incompatible with previous research. The whole manuscript is very well composed and arranged. The missing tree species is a small mistake, but it is a very minor issue. for example, the author designed a model tree and experimented with the model. It has a round crown and a 'clear length'. We understand it is just a model, but it'll be better for the reader if the author gives an example tree species.

Author Response

Please see the attachment file. Thank you very much.

Author Response File: Author Response.pdf

Reviewer 3 Report

The author conducted an interesting study to simulate the effect and variation of a single row of trees on the effect on wind speed by using models with different heights and plant spacing, which provides a reference for the selection and planting of street trees and has some research value. The following modifications are suggested:
1. Add a map of the geographical location of the study area and set a series of parameters such as ground conditions and wind strength according to the actual situation of the study area.
2. Please explain how the model was developed. Because the canopy is considered a porous medium with varying porosity and air permeability coefficients, the models should not all be the same.
3. In line 70 a tree factor is mentioned, please specify.
4. Table 1 only gives the parameters of the physical model tree, it is recommended to list the actual model parameters in the Ansys Fluent simulation.
5. It is recommended to add the instrument information of the wind speed probe.
6. In the study, the widest plant spacing is 1.8 times the crown width. For a tree with a height of 15 meters, whether the spacing is too narrow will affect the accuracy of the simulation results. Please explain.

Author Response

Please see the attachment file. Thank you very much.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The paper developed a lot, it is almost acceptable for publication.

Please take care of the spelling of the tree species, Koelreuteria elegans. Sometimes it appears as 'elegan'. We generally write the Latin name in italics, and you may use the English name too. Golden raintree

The discussion and Conclusion parts are not clear. Some evaluation type points would be better to add to the Discussion (line 375-390) as these statements are relevant founding of the survey. The paragraph in lines 349-359 should be edited to the Conclusion as it is about the possible further usability of the survey. One more question remains as a general part of the Conclusion, and that is the further research ideas, aims, questions not answered fully.

 

Author Response

Please see the attachment file.

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors have carefully revised and refined the above issues, and it would be useful to add the shortcomings of this study and a comparison with related studies in the discussion section.

Author Response

Please see the attachment file.

Author Response File: Author Response.pdf