The Use of Remote Sensing to Quantitatively Assess the Visual Effect of Urban Landscape—A Case Study of Zhengzhou, China

Round 1

Reviewer 1 Report

Review comments: Manuscript ID:- remotesensing-1514372

General Comment

This is an interesting manuscript about the use of remote sensing to assess visual effect of urban landscape in the study region. However, there are aspects that require improvement and clear presentation before being considering for publication. Specific comments and suggestions are included below.

Specific comments and suggestions

L57-67: I suggest including earlier studies about the use of Elo rating system for quantifying landscape vision. Specifically, more to their gaps and how the present study will address them. If the present study is a first of its kind, it should be clearly presented.

L84-88: What does the samples “randomly picked” mean? Authors need to clearly describe the sampling techniques used together with the underlining reasons.

L89-90: When was the survey conducted?

L93-95: Authors need to include a reason for the choice of month (April) and year (2017) for the Landsat 8 OLI images used in this study. What kind of supervised classification algorithm used and why? How the accuracy assessments of your classification performed?

L95-96: DSM with how much resolution? As can be observed, there could be different outputs as the datasets (e.g. Landsat, ZiYuan-3) has different resolutions. How the data standardized for further processing to achieve the intended objectives?

L110-113: Why fifty points chosen for the model construction? Any base?

L113: Why four sampling points for the validation? Any base? Why the validation samples collected independently?  Why not collecting all at once and divide training and validation samples. Otherwise, how to avoid taking the sample site as training and validation samples?

L120-121: Why atmospheric correction needed for this study?

L125: I suggest to describe the classes in a table.

L125-127: Sampling procedure for the classification is confusing. Which sampling techniques used? What does the samples evenly selected to the whole image mean? How many samples per class used for the training (minimum sampling numbers)? As stated above (L93-95), how the accuracy assessments of the classification results performed?

L189-200: This is method not results. I suggest moving to appropriate section.

L318-404: the current version of the discussion are more extended presentation of results. I suggest reworking to this part. Generally, the discussion part need to address the following points: how this study will increase our knowledge base and inspire others to conduct further research, how the study results (not) support findings of earlier studies, and whether your findings agree with current knowledge and expectations.

Author Response

Please see the attachment

Author Response File: Author Response.DOCX

Reviewer 2 Report

This article approaches the issue of the quantitatively assessment the visual effect of urban landscape using a case study from China.

The abstract needs to be improved since it's not clear which is the main objective of this article and which is (are) the main conclusion(s).

The references are not always introduced correctly in the text. Please check the MDPI rules and review these aspects.

At the end of section 1 - Introduction - please clearly mention which steps (stages) do you follow to reach and results.

Please improve the size and quality of figure 1 so the text can be easily readable. 

Section 2 - On which basis did you select the representatives areas? Which criteria did you used in this direction?

It is very difficult to read on figure 3 the names of the selected areas and to correlate them with the results. Please improve the figure or provide more explanations.

Who answered at the questionnaires? Please provide more information on the respondents. 

It is not clear how many answers do you get for these questionnaires. 

Please improve figure 5. The values are hardly readable.  

Please try to establish some clear links between different figures, results and discussions. It is very difficult to follow which picture was taken from where and how is it assessed based the results of your study.

Please also improve figure 9. It is impossible to see/ read which are the considered 5 factors.

The scientific and technical features of this article are good but, overall, the article needs to be improved in terms of quality of presentation, informational flow, clarity.

There are also some shortcomings in terms of methodology (the part regarding the questionnaires).

Major revision is required.

Author Response

Please see the attachment

Author Response File: Author Response.DOCX

Reviewer 3 Report

This study applied remote sensing and machine learning techniques to measure the visual effects of the urban landscape. Overall, the methods are described in sufficient detail, but the significance of this work is unclear, and the discussions need more elaborations. Specifically,

1. Improving people's visual experience seems like a vague goal. What are the specific benefits and usefulness of evaluating the visual effects of the urban landscape? What are the applications?
2. Please give more details of the experiment and questionnaire setup, packages being used, training time, who participated in the questionnaire, etc.
3. Figure 4 shows the authors' own interpretation of three panoramic pictures. It would be better to summarize the features from the questionnaire statistics.
4. The patterns in Figure 9 are not so obvious. It would be better to add some elements or use a different plot to more clearly show how the feature influence the score
5. I would suggest adding a paragraph in the conclusion to demonstrate how the proposed method can be applied and also what are the future works

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 4 Report

Considering the domain of the journal I have some doubts if it fits to the scope. By strengthening technical aspects of the study (mostly in introduction and discussion) could be helpful for better adjusting to the domain of journal’s interests. That is general comment which should influence whole “story telling” of the manuscript

Moreover, I present some additional comments which should be taken into account while improving the paper:

1. Improve the quality of figures 1 and 5 in order to increase their readability.
2. Discussion section focus on results obtained in this study, but it is missing comparative discussion confronting obtained results with outcomes of other studies. Are your results similar to other conducted in that field? Do they differ from other studies? What are the probable reasons of such situation? Are there any limitations that you can highlight in your research (accessible data, method, etc.)?
3. Moreover, I suggest to compare results of your study to other research on approaches for land use change over time. Please see for instance: A framework for path-dependent industrial land transition analysis using vector data. European Planning Studies 2019, Volume 27(7), 1391-1412; Identifying core driving factors of urban land use change from global land cover products and POI data using the random forest method. International Journal of Applied Earth Observation and Geoinformation 2021, Volume 103, 102475; and other papers in that field. Understanding the mechanisms of urban transformation and possible future land uses may influence aesthetic aspects in city planning.

I encourage the Authors to correct the paper, as in my opinion it presents an interesting study and might constitute a valuable paper after improvements mentioned above.

Author Response

Please see the attachment

Author Response File: Author Response.DOCX

Round 2

Reviewer 2 Report

Overall, the authors provide relevant answers to the questions raised after the first review.

There are still some unclear aspects on the questionnaires that were applies, and especially who were the respondents (just providing numbers and a gender classification is not enough). It would have been interesting to see which professions, skills, studies had the respondents. However, the authors can approach these aspects in a future complementary study.

Reviewer 3 Report

The revision addressed my concerns.

Reviewer 4 Report

The paper has been corrected according to my previous comments and in my opinion it can be published in the current form.