Multi-Scale Remote Sensing Assessment of Ecological Environment Quality and Its Driving Factors in Watersheds: A Case Study of Huashan Creek Watershed in China

Round 1

Reviewer 1 Report

General Evaluation:

The current manuscript entitled “Multi-scale Remote Sensing Assessment of Ecological Environment Quality and Its Driving Factors in Watersheds: A Case Study of Huashan Creek Watershed in China” by Liao et al. investigated a Chinese watershed system in terms of ecological environment quality and their driving factors. After a careful evaluation, I found that this manuscript requires major improvement before it can be considered for publication in the Remote Sensing journal. In general, several sections of the manuscript are poorly written and need to be restructured and written more scientifically. I suggest major revision and my specific comments are as follows:

Abstract:

This section is poorly drafted. Authors should write it again with more focus on the following aspects: why this study was necessary for the given reason? What were the objectives? What was the method used? What are the major numerical results of this study? What is the overall outcome of this study in terms of monitoring and conservation of Huashan Creek Watershed in China? Please write at least one sentence for each of the above questions which will give you a well-structured and scientific abstract.

Line 20-21: no logical meaning to this sentence, why it is vital for informed sustainable development? The claim is too broad based on the limitations of the study.

Introduction:

Line 33: Please delete the redundant word “Consequently”.

Line 43: RSEI: full form?

Line 50-51: unclear sentence.

Line 78: better to write as “The objectives of this study were to …”.

Methods:

Figure 1: caption should be rewritten as: Digital elevation model (DEM) based map of Huashan Creek Watershed in China.

Table and figure captions: provide just 2-3 words don’t make your figures and tables informative enough. The captions must be rewritten so the reader can get an exact idea of what those tables and figures are meant for.

Table 1: Please provide dates of data extraction, resolution, copyright, and range of data used as new columns.

Table 2: The explanations column is just a repetition of the formula. What actually Bblue and other terms denote? Please write it clearly.

References are missing for most equations and models used in this paper.

Results and discussion:

Fine, but should be strengthened with supporting evidence for the reasons why elevation showed influence in most cases? The same goes for other variables too? The comparison with recent literature is insufficient.

Correct spacing and syntax problems in the entire manuscript.

Conclusion:

Fine, but can be shortened to less than 300 words and several sentences that already appeared in other sections must be avoided.

References:

Fine and up to date.

Please consult a native speaker or editing service to correct English of your manuscript.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments

General comments

Although I have no previous experience in conducting field work inside China, I have visited the captioned study area, namely Huashan Water Creek area. I believe that my first-person field trip experience would be useful in contributing to the quality improvement in this manuscript. Also, I have conducted RS data analysis using secondary data. Therefore, I believe that I would be eligible to being a reviewer for this manuscript.

Introduction 

Line 26 to 38

The first paragraph of the Introduction section can be trimmed down for the purpose of brevity and conciseness. It is well understood that the authors would like to give readers a general problem that is faced worldwide, and later zoom into the localised situation in China. 

The authors are correct in the sense that no too many numbers and figures were cited in the first paragraph. Still, it would be advisable to jump into the main research problem quickly after a short general introduction. 

Line 39 to 59

In these paragraphs, the authors tried to summarised the existing techniques in remote sensing and a few of their applications in China. It would be generally agreed that these techniques are suitable and useful for remote sensing applications. The authors may need to distinguish remote sensing methods from their subsequent data analysis strategies.

More importantly, the authors are suggested to locate representative empirical studies that have been conducted in the Huashan Water Creek region. Any past findings would be valuable for the understanding of the current research status as well as the cross-comparison of the data collected for the present study.

Line 69 to 73

The data analysis technique, namely Geographically Weighted Regression, is a technique for spatial analysis. The authors should review its suitability of potential application in the study area. 

Readers need more elaboration on the usefulness of this technique. Also, the authors may try to elucidate how this technique stands out from other possible data analysis techniques. 

Methods

Line 85 to 92

Please specify the type of climate as in the Koppen-Geiger climate classification. This information can be easily found. 

Line 93 to 99

Although I am not a pedologist, I am able to tell that the soil types which are shown in this paragraph are not the proper terms for describing the actual soil classes. 

It ia possible that the authors used direct, literal translation of the local language. It is suggested that proper terms should be used when indicating soil classes. 

Line 100 to 107

Are there any official statistics on the agricultural use of water? Given that the majority of the land area, the amount of water used by farmers may be influental on the water cycle within the study area. 

Line 128 to 129

Please insert citation for each of the statistical softwares.

Line 195 to 208

PC2 has a higher proportion than PC1. Why did the authors prefer the latter?

Line 324 to 333

Previously, the authors mentioned that there are five spatial resolution levels used for this study. Are there any effective comparison in the GWR results between different resolution levels?

Results

Line 368 to 370

It is understood that a change in the spatial scale of analysis would lead to different visualisation of RESI. It is wondered whether any areas displayed RESI from 0 to 0.2. 

As mentioned in the Introduction, agricultural activities had impacts on the ecosystem. It is wondered how such effects were manifested.

Line 371 to 372

The top four sub-plots show similar bar charts. Yet, the line overlay on the bars of the top left sub-plot seems to be different from the other sub-plots. 

Also, the sub-plots can be indicated by alphabets. It is advised that alphabets could be added for clarity. 

Line 382 to 385

The meaning of this sentence is unclear. Please revise it. 

Line 431

There seems to be a typo in the top left cell of Table 5. Please correct it.

Line 436 to 444

I wonder whether the differences in the Moran value would be sufficiently significant to affect the choice of the spatial scale.

Discussion

Line 730 to 739

From this section, it is understood that 240 m grid would be preferred for the analysis regarding RSEI. I believe that the authors can also elaborate the possible applications of the other grid scales. 

Minor editing and polishing of the language would be needed

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors of the manuscript entitled: " Multi-scale Remote Sensing Assessment of Ecological Environment Quality and Its Driving Factors in Watersheds: A Case Study of Huashan Creek Watershed in China". I have thoroughly reviewed your work. I consider it a very relevant work considering the assessment of the environmental quality of a river basin taking into account the use of remote sensing. However, minor modifications are necessary before publication.

Keywords

L22-23: It is not advisable to use keywords consisting of more than one term.

Introduction

This introduction is well structured, showing the relevance of the topic, problems, previous application studies, research objectives and the use to which the research will be put.

L60-73: Dear authors, please merge these two paragraphs into one

Materials and Methods

L113: Figure 1: The design and resolution of this map needs to be improved. Each map should be in a box and differentiated with a letter that should be explained in the description of the figure.

L566: Figure 8: The resolution of this map needs to be improved so that the information can be visualised in detail. Due to the amount of information presented, I suggest placing it in supplementary material.

Discussion

The discussion is very well structured, discussing each of the results obtained for the stated objectives. In addition, it shows the limitations and future research suggestions.

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Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The manuscript has been improved and ready for publication. Thanks to authors for considering my inputs in revision.