Spatiotemporal Changes of Glaciers in the Yigong Zangbo River Basin over the Period of the 1970s to 2023 and Their Driving Factors

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this manuscript, the author analyzed the glacier spatiotemporal variation incorporating the existing glacier inventory data in the Yigong Zangbo River Basin in southeastern Tibet Plateau for the years 1988, 2015 and 2023 utilizing Landsat and Sentinel-2 imagery. This endeavor will enhance understanding of glaciers interplaying with topographic elements, glaciers features and climatic adaptability within the basin. Unfortunately, the data quality is unreliable and lacks rigorous experimental design in this manuscript. The authors could do much better job on analyzing and presenting the data. Followings suggestions need to be improved: 

1) The fitting equation in Figure 3 is a polynomial, but the fitting line shows a linear relationship.

2) The range selected by the red box in Figure 4 is 4800~5300, but the enlarged image on the right shows a range of 5100~5400.

3) The ice volume which calculated using formula (2) and the glacier area given in Table 2 has significant difference with the ice volume given in Table 2. What is the reason for this.

Author Response

We would like to thank you for your careful reading, helpful comments, and constructive suggestions, which has significantly improved the presentation of our manuscript. The responses to the specific comments can be found in the attachment (pages 1-2)

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Glaciers in Tibetan Plateau show a significant shrinkage with a spatial variability, particularly, the southeastern Tibetan Plateau (SETP), resulted from local climate during the past several decades. I have reviewed the manuscript of “Spatiotemporal changes of glaciers in the Yigong Zangbo River Basin over the period of 1970s to 2023 and their driving factors”. The authors produced a glacier inventory in Yigong Zangbo River for 1970s-2023. This work is benefit to understanding the rapid glacier retreat in SETP.

Major comments:

(I) The Landsat series of images was applied to extract the glacier boundary in the paper, and the authors should add which series were used, including the acquired dates of those images. In addition, glacier mass balance in the region for 2000-2019 was analyzed, while the method of calculating mass balance using ICESat-2 and ASTER should been described.

(II) Changes in glacier area indicated that the glacier retreat of small area was more significant than the ones of large area. However, the larger glacier incurred more mass losse during the study period than mass loss of the small glacier. For example, “Glaciers smaller than 1 km² altered their mass loss by 0.45 m w.e. a^-1 (accompanied by an elevation change of -10.16 m), while those exceeding 50 km² have seen this value rise to 0.73 m w.e. a^-1 (with elevation reduction of 16.24 m). Are these two conclusions contradictory? Please further explain their reasons.

 

Specific comments:

L36: “temperature” Change to “air temperature”.

L212: Please add specific threshold values for separating glacier from free-glacier.

L289: Please add the references to uncertainty formulae, i.e., the formulas (5), (6), and (7).

L325: “Glaciers” change to “Glacier area”.

L346-348: “Orientation is another critical topographic factor that significantly affects the energy balance of glaciers by influencing temperature and precipitation, leading to distinct variations in glacier area distribution by direction [54,55].” Remove it to discussion.

L407: “the northern bank”?

L417-418: Attention to norms and consistency of presentation, e.g. “R2 of 0.8”, “(m w.e. a-1)”, “km2”, “kg·m-3”, “0.10±0.08%·a^-1” and “+0.02±0.01%·a^-1”, et al.

L479-483: Remove it to introduction section.

L505-507: Delete.

L513: “temeprature” Change to “air temperature”.

L533: Please specify the exact months of the spring and ablation seasons.

L555-557: “In the YZRB, central and eastern regions are experiencing a notable rise in average melting period temperatures, leading to significant shrinkage of the Niwu Zangbu basin glaciers [1]. “Which region has changed more dramatically in terms of glacier area and material balance between east and west mountain regions?

L562-564: Please add the references.

 

Figures:

Figure 1: The legends and maps should be clearly distinguished.

Figure 2: I don't think the Figure 2 is very useful in the paper, either delete it or add to it.

Figure 6: Replotting and introduction of the specific angle of slope direction.

Figure 11: The legends for the moving average and the linear fit are reversed.

Figure 12: The spatial difference of changed trend in air temperature and precipitation was significant, and please add the statistical significance test level.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

I can understand the paper.

Author Response

We would like to thank you for your careful reading, helpful comments, and constructive suggestions, which has significantly improved the presentation of our manuscript. The responses to the specific comments can be found in the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Article is not novel, the presented results are in line with precious findings and the discussion does not bring any new thoughts that would change our understanding of the processes occurring at HMA glaciers

Comments on the Quality of English Language

english is ok

Author Response

We greatly appreciate the reviewer’s comments and provide the following explanation:

①Against the backdrop of climate warming, the glaciers in southeastern Tibet Plateau (SETP) are experiencing accelerated retreat and a continuous negative mass balance. Our study analyzes the long-term and multi-temporal glacier changes in the Yigong Zangbo River Basin (YZRB) and finds that the glacier retreat rate has underwent some fluctuations which are highly consistent with temperature changes. Specifically, the retreat rate initially decreased from 1.07±0.24% a^-1 to 0.78±0.12% a^-1, then slightly increased, culminating at 0.85±0.33% a^-1.

②The results of this study are largely consistent with existing research. Although it may lack novelty, this study has completed the latest glacier inventory of the YZRB for the year 2023 and extended it back to the 1970s, providing a basis for understanding the current state of glaciers and changes over the past 50 years.

③This study further confirms the significant impact of global warming on the maritime glaciers in SETP, offering insights into the response mechanisms of SETP glaciers to climate change. Given the ongoing trend of global warming, it is expected that the maritime glaciers in this SETP will continue to retreat significantly, necessitating broader attention and research.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

1. Adjust the starting scale of the right vertical axis coordinate in Figure 4 to start from 0.

2. Change WS to SW in Figure 7.

3. The author drew Figure 8 using the data from Table 3, and there is a duplication between the two. It is recommended to keep one of them.

4. In Figure 6, the number of glaciers in 2023 is only 1975, while in Figure 9, the number of glaciers counted by the author is 2518. It can be seen that the number of glaciers that have disappeared in such a short period of time is very astonishing. It is recommended that the author provide a quantitative explanation.

5. The author only provided captions for Figures 9, 10, and 11, but there is a lack of corresponding explanations and annotations for the figures in the main text.

Author Response

We would like to thank you for your careful reading, helpful comments, and constructive suggestions, which has significantly improved the presentation of our manuscript. The responses to the specific comments can be found in the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

All the issues I raised have been addressed by the author and there are no further new comments.

Author Response

We sincerely appreciate your re-evaluation of our manuscript and the valuable feedback you provided. We are pleased to see that you believe we have satisfactorily addressed the previously raised issues and that you have no further comments.

We are committed to continuing our efforts to ensure that our research work and manuscript writing meet the journal’s standards. We are very grateful for the time and effort you have invested in the review process, which has been extremely helpful for the improvement of our research and manuscript.

Please continue to oversee our work, and if there are any questions or further information needed in the future, we warmly welcome your input. Thank you once again for your support and assistance.