Alpine Wetland Evolution and Their Response to Climate Change in the Yellow-River-Source National Park from 2000 to 2020

Round 1

Reviewer 1 Report

The article is entitled 'Alpine Wetland Evolution and Their Response to Climate Change in the Yellow-River-Source National Park from 2000 to 2020'. The authors made a simple analysis of the relationship between the decrease in the wetland area and the increase in the average annual air temperature and the amount of annual precipitation sums. The article is interesting, but in my opinion it needs to be supplemented:

- no specific research goal

- a diagram/scheme of the research methodology should be provided

- insert the names of the bordering countries and the research area

- explain how evapotranspiration was calculated for which area / gauge stations

- supplement the discussion with a new references item. Compare the rate of decline of lakes and wetlands with other areas for different climatic zones

Technical Notes:

- Table 2 - please provide units

- Line 488 is ‘LANG, Q .; NIU, Z .; HONG, X .; YANG, X. Remote Sensing Monitoring and Change Analysis of Wetlands in the Tibetan 488 Plateau. Geomatics and Information Science of Wuhan’ and it should be ‘Lang, Q .; Niu, Z .; Hong. X .; Yang, X. …’

- Line 495 is 'Environmental earth sciences' and it should be 'Environmental Earth Sciences'

- And many others ..

Author Response

Author Response File: Author Response.docx

Reviewer 2 Report

The work by Ma et al. presents a remote sensing analysis of alpine wetlands in the Yellow-River-Source National Park from 2000 to 2020. It aims to reveal the evolution of different alpine wetland types in the YRSNP and their response to climate change. An interesting and novel approach is presented, namely the use of an object-based classification model to carry out wetland classification and extraction in the YRSNP from 2000 to 2020. This is followed by grey relation analysis and correlation analysis to examine response of changes in the alpine wetlands under study. The study addresses very relevant research questions with scientific and management applications. My main concern is that the presentation of the two main analysis methods, namely the Object-based Wetland Classification Method  and  Grey Relation Analysis Method is very brief, and it may be very difficult for the reader to understand how they were implemented. Regarding the object based classification method, I suggest the authors provide a more detailed account, such as the one presented in Mahdianpari et al. (2019). As it stands, the method section does not provide information as to how scale segmentation and classification rule set setting are performed, other than referring the reader to the information provided by the software developer. This insufficient to allow independent reproduction of the analysis presented. It would be useful it the authors could comment on the interpretation of the kappa values obtained, and whether they provide an average, good or excellent classification success.  Regarding Gray Relation Analysis, it is not clear whether this is carried out at the pixel level or at the level of the objects previously identified. It would be very helpful to provide further details as to what processing software or platform was used to implement this analysis, and to further explain how it interacts with the previous analysis. Another point which requires attention is what is the range of values that GRA produces and what is their interpretation. In other words, what is the meaning of γ and how is it interpreted?

In this regard, it would be interesting to know whether the analysis presented is able to determine causal relationships, or whether it could have been enriched by alternative methods that go beyond the analysis of correlations, such as structural equation models. I suggest the authors discuss this point and whether alternative analysis methods would provide more confidence on the interpreted causal relationships. 

Minor comments

The authors do not explain why the data in Table 3 does not provide values for the Kappa coefficient and Overall Accuracy for River wetland and Marsh wetland classes. Is there any specific reason for this imbalance? How does it affect the conclusions of the study?

I found a minor typo on line 124, " rive wetlands" should be edited to " river wetlands"

Author Response

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors made the suggested corrections. The article has been significantly improved.