Study on the Variations in Water Storage in Lake Qinghai Based on Multi-Source Satellite Data
, Jialong Sun 1,2,3,4, Jiajia Yuan 7,* and Jinyun Guo 8Round 1
Reviewer 1 Report
Comments for author File: 
Comments.pdf
Author Response
Q1: 1-Pls give a clear view of the study area. The location of the lake should be pinpointed in China.
2-A high quality map would be better
Our response: Thanks for your comments. We modified the Figure 1 (line 159).
Q2: Which mission? Pls be precise in captions.
Our response: Thanks for your comments. We rephrased the captions (lines 160-162) and marked in red.
Q3: Revisit span of all the altimetry missions should be stated.
Our response: Thanks for your comments. The revisit span of all the altimetry missions were added and marked in red (lines 183, 187-188, 193, 196, 204).
Q4: Pls clarify what did you do exactly to these images with relatively higher cloud coverage rates? any preprocessing?
Our response: Thanks for your comments. Although there is a relatively higher cloud coverage in these images, the cloud in these images does not reach the Qinghai Lake border, so the cloud in images have not been processed.
Q5: Give a reference for this.
Our response: Thanks for your comments. The reference was added and marked in red (line 268).
Reviewer 2 Report
In this paper, a high-precision lake water level variation dataset for every 10 days from July 2002 to December 2022 using the multi-source altimetry satellite SGDR data was created. and Landsat 8 Operational Land Imager data, an averaged area series of Lake Qinghai for each year’s September to November from 2002 to 2019 is produced. The reviewer thinks the topic discussed in this paper is very important, which is of great significance for research of debris flow. This reviewer sees that a minor revision will be needed before being accepted for possible publication. Here are the main comments for the revision.
(1) A key problem in this paper is the lack of introduction to the applicability of the proposed method.
(2) The introduction section lacks some important references, such as:
https://doi.org/10.1007/s00477-023-02394-4;
https://doi.org/10.1109/IGARSS.2018.8517603 ;
https://doi.org/10.1016/j.enggeo.2022.106779 .
(3) The font in Figure 1 is too small. It is recommended to enlarge it appropriately.
(4) The structure of Figure 2 is quite responsible, which is confusing. It is recommended to simplify it appropriately.?
(5) Figure 9 lacks important information such as scale and north arrow.
(6) It is suggested that the author briefly summarize the reasons for the capacity change of Qinghai Lake.
(7) The conclusion is not concise and innovative. I believe that the Authors should try to interpret and explain more clearly their results. Some key quantitative conclusions should be supplemented.
(8) In this study, the authors must improve the statements about what is new in their study and what are the contributions to the developments of agriculture.
Author Response
Reviewer #2:
In this paper, a high-precision lake water level variation dataset for every 10 days from July 2002 to December 2022 using the multi-source altimetry satellite SGDR data was created. and Landsat 8 Operational Land Imager data, an averaged area series of Lake Qinghai for each year’s September to November from 2002 to 2019 is produced. The reviewer thinks the topic discussed in this paper is very important, which is of great significance for research of debris flow. This reviewer sees that a minor revision will be needed before being accepted for possible publication. Here are the main comments for the revision.
Q1: A key problem in this paper is the lack of introduction to the applicability of the proposed method.
Our response: Thanks for your comments. We added the introduction to the applicability of the proposed method (lines 744-746) and marked in red.
Q2: The introduction section lacks some important references, such as:
https://doi.org/10.1007/s00477-023-02394-4;
https://doi.org/10.1109/IGARSS.2018.8517603 ;
https://doi.org/10.1016/j.enggeo.2022.106779 .
Our response: Thanks for your comments. we added the reference https://doi.org/10.1109/IGARSS.2018.8517603; (reference [54]) and marked in red.
Q3: The font in Figure 1 is too small. It is recommended to enlarge it appropriately.
Our response: Thanks for your comments. We modified the Figure 1(line 159).
Q4: The structure of Figure 2 is quite responsible, which is confusing. It is recommended to simplify it appropriately.?
Our response: Thanks for your comments. we revised Figure 2 and make it more clearly (line 258).
Q5: Figure 9 lacks important information such as scale and north arrow.
Our response: Thanks for your comments. We modified the Figure 9 (line 509).
Q6: It is suggested that the author briefly summarize the reasons for the capacity change of Qinghai Lake.
Our response: Thanks for your comments. We added the description of the reasons for the capacity change of Qinghai Lake (lines 700-734) and marked in red.
Q7: The conclusion is not concise and innovative. I believe that the Authors should try to interpret and explain more clearly their results. Some key quantitative conclusions should be supplemented.
Our response: Thanks for your comments. We revised the description of the conclusion and the revisions are marked in red (lines 741-750).
Q8: In this study, the authors must improve the statements about what is new in their study and what are the contributions to the developments of agriculture.
Our response: Thanks for your comments. We revised the concluding description, and due to an absence of statistics on lake runoff and agricultural water use, we did not evaluate agricultural effects in our findings. We are going to include relevant material in future studies.
Reviewer 3 Report
The paper deals with the interesting issue of using remote sensing for the study on the variations of water storage in lake. The work requires the following corrections before publication.
The methodological part of the work is described in detail, however, there remain some issues that need to be clarified.
I don't really understand the idea of using remote sensing techniques for the Lake Qinghai in which the water levels are observed. It would make more sense to transfer the methodology to unmonitored lakes.
In the paper, the authors analyze water storage and do not present a bathymetric plan of the lake. Water storage changes are not only dependent on water level fluctuations, but also morphometric changes. Therefore, how did the lake bottom change during the analysis period (2002-2022)? How was the magnitude of sediment deposition and, consequently, the scale of its shallowing and reduction of the lake's retention? Certainly, estuaries are the most dynamic in this regard, but not only.
The article does not have a Discussion chapter. Admittedly, it is included, but its content contains the results of the study. Reference to any (!) other studies of a similar nature has not been undertaken there. This needs to be changed.
Similarly, the Conclusions chapter, where specific values are cited (duplication of results) and there is no synthetic information about the study conducted. What are its limitations?
Author Response
Reviewer #3:
The paper deals with the interesting issue of using remote sensing for the study on the variations of water storage in lake. The work requires the following corrections before publication.
Q1: The methodological part of the work is described in detail, however, there remain some issues that need to be clarified.
I don't really understand the idea of using remote sensing techniques for the Lake Qinghai in which the water levels are observed. It would make more sense to transfer the methodology to unmonitored lakes.
Our response: Thanks for your comments. I agree with you, we revised the concluding description (lines 741-746) and explain the reason why use remote sensing techniques for the Lake Qinghai, the revisions are marked in red (lines 741-746).
Q2: In the paper, the authors analyze water storage and do not present a bathymetric plan of the lake. Water storage changes are not only dependent on water level fluctuations, but also morphometric changes. Therefore, how did the lake bottom change during the analysis period (2002-2022)? How was the magnitude of sediment deposition and, consequently, the scale of its shallowing and reduction of the lake's retention? Certainly, estuaries are the most dynamic in this regard, but not only.
Our response: Thanks for your comments. I agree with you, changes in lake bottom topography is one of the reasons for the variation of water storage, we revised the discussion description (lines 700-734) and briefly summarized the reasons for the capacity change of Qinghai Lake.
Q3: The article does not have a Discussion chapter. Admittedly, it is included, but its content contains the results of the study. Reference to any (!) other studies of a similar nature has not been undertaken there. This needs to be changed.
Our response: Thanks for your comments. We revised the discussion description (lines 700-734) and marked in red.
Q4: Similarly, the Conclusions chapter, where specific values are cited (duplication of results) and there is no synthetic information about the study conducted. What are its limitations?
Our response: Thanks for your comments. We revised the conclusions chapter. Our study's limitations include the lack of additional examination of water storage balance and climatic factors, as well as the absence of the motive for lake water storage fluctuation and the percentage of various components in the change process. We will include pertinent information in future research.
