Spatiotemporal Variations in Snow Cover and Hydrological Effects in the Upstream Region of the Shule River Catchment, Northwestern China
Round 1
Reviewer 1 Report
This is a well written manuscript which is almost ready for publication as is. I have no suggested edits only two points that need a bit of clarification.
1) In figure 4 is the percent of snow cover computed wrt area above elevation or total Shule catchment area?
2) Does figure 6 show results for March thru May?
Author Response
We had a special reply with office word revision.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The reviewer is really grateful to the authors for the outstanding and so vital nowadays research about spatiotemporal variations of snow cover and hydrological effects in the upstream region of the Shule River catchment, northwestern China. The authors extracted data set of snow cover in the upstream region of the Shule River catchment using MOD10A2 data from 2000 to 2019, and analyzed the spatiotemporal variations of snow cover and its meteorological, runoff, and topographic impacts. The results show that the spatial distribution of snow cover is highly uneven owing to altitude differences.
However there are some minor inconveniences somewhere in the text connected with the reference formatting and other. So there are some texts like ‘[CrossRef]’ in the end of almost each reference, which from the reviewer’s point of view can bear no essential meaning.
Author Response
We had a special reply with office word revision.
Reviewer 3 Report
The paper deals with snow cover extent and its hydrological effects in the upstream region of the Shule River catchment. Spatiotemporal variations of snow cover based on the MODIS/Terra8 daily snow data (MOD10A2) were analyzed in 2000-2019 together with meteorological parameters from the selected AWS, runoff data, and topographic features of the catchment. The paper is in the scope of the journal, is concise, and generally well written. The gathered data support the analyses and conclusions. My critical remarks concern:
1) Missing information on general climate conditions of the study region (see below).
2) Some meteorological parameters (air temperature, precipitation amount), which are not correctly displayed/analyzed in the manuscript, although they are referred to by the authors in the results (Chap. 3.4. and 3.5).
3) Insufficient discussion and lack of information in the regional context, e.g. in relation to climate change and the implications for snow cover and runoff in the studied region (see below).
I recommended to accept the paper for publication after major revision. Specific comments are below.
Major comments:
In the chap. 2 Basic information on climate conditions of the study region (air temperature, snow depth, and snow cover extent and variation) based on published reports/articles, should be inserted in this chapter. I also recommend creating an additional map showing the slope variation, glacier and permafrost extent within the study region. Moreover, I recommend inserting an additional plot (hypsometric curve), which will be helpful to present basic geographical conditions of the catchment.
In chapter 3.4. (L218, L222) the authors interpreted the results of snow cover extent and runoff from the catchment, using precipitation regime ("... slight increase of precipitation"). However, precipitation data are completely missing in the results to support your statement. Clarify in the main text or insert a plot showing the precipitation pattern or variation, based on e.g. AWS measurement. Similarly, in the next paragraph (L223-245) information on air temperature is used for explanation of the snow cover melting or glacier ablation / type of precipitation. Therefore, I recommend inserting a table or plot (to the main text or annex) showing air temperature changes with altitude to support this assertion.
In chapters 3.4. and 3.5. I would welcome enlarging a discussion on meteorological parameters, snowmelt, glacier ablation (as driving factors) on runoff variation, using other papers and relevant studies to support the statement. Comparison of your findings with other studies at local and regional scales on climate change will also improve the manuscript significantly.
Minor comments:
L26: Keywords "geological causes" are not suitable because there is no information about it in the main text. Maybe you mean "topographic causes"?
L34-35: The sentence/information should be supported by the relevant reference.
L71-72: From which data source or map the glacier and permafrost areas were calculated? Adding relevant reference(s) will be very useful.
Figure 1: I recommend creating a new figure or improving the present one by inserting the glacier and permafrost edges in the map, to support information in text in L71-72
L77-78: The sentence/information should be supported by the relevant reference(s).
L95: Insert the name of the "national station" and its coordinates or clarify that you are talking about the automatic weather station in the Laohugou Glacier region?
L98: Clarify what you mean "conventional approaches" - Please explain or refer to e.g. WMO observation and data quality manuals or reports.
L119-120: Insert a web-page of the ARCGIS10.7. and ENVI5.5 software.
L153 - Figure 2: Enlarge a font size of caption used for the individual seasons.
L205: Caption of the Figure 4 states "absolute snow cover extent (km2)" while the plot legend says "Coverage ratio of Snow cover / %". Clarify or modify the legend or the figure caption.
L205 - Figure 4: Change the color of the marks in X- and Y-axis - there are almost invisible now.
L207-213: This paragraph belongs to a discussion, and must be move on (down) in the chapter. Your own results and analysis should be present at the beginning of this chapter first.
L247 – Figure 5: There is a mismatch between the caption of the figure (snow cover extent) and the plot with "Pixel numbers". Can you recalculate and change the parameter of the X-axis from "Pixel numbers" to Snow cover extent in square km?
L250: Title of the chapter is confusing and should be modify, because “….climate change” is not presented or discussed there. What about: “Influence of terrain and climate parameters on snow cover?
L272-275: There are no results/analyses in the manuscript, describing precipitation and temperature changes from 2000 to 2019. These facts should be correctly presented in a form of a graph or table, or supported by findings of other studies.
Correct writing of the axis caption and units in all plots should be checked, e.g. Elevation (m), Coverage ratio of snow cover (%).
Author Response
We had a special reply with office word revision.
Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
The revised version of the manuscript has been significantly improved. The authors had met all remarks and suggestions. In my opinion, this paper rises to the standard of Remote Sensing MDPI journal and can be accepted for publication in the present form. Well done.
Reviewer
Author Response
Dear Editor:
On behalf of all co-authors, we appreciate you and reviewers very much for your positive and constructive comments and suggestions on our manuscript entitled “Spatiotemporal variations of snow cover and hydrological effects in the upstream region of the Shule River catchment, northwestern China”.
We have tried our best to revise our manuscript according to the comments, and our point to point responses are listed below every question.
We would like to express our great appreciation to you and reviewers for comments on our paper.
Looking forward to hearing from you.
Thank you and best regards.
Yours sincerely
Wentao DU
Reviewer:
The revised version of the manuscript has been significantly improved. The authors had met all remarks and suggestions. In my opinion, this paper rises to the standard of Remote Sensing MDPI journal and can be accepted for publication in the present form. Well done.
Answers: Done.
- The year of every references had been revised to bold font according to the format requirement of Remote Sensing.
- All of figures had been replotted with resolution of above 600dpi.
- We unified the expression of “upper region” in the revised manuscript.
Author Response File: Author Response.docx
