Quantifying the Spatio-Temporal Variations and Impacts of Factors on Vegetation Water Use Efficiency Using STL Decomposition and Geodetector Method
Round 1
Reviewer 1 Report
Τhe paper deals with a very important topic and thematically is well-targeted and appropriate to the journal scope. It is well structured and gives remarkable results for the correlation of the examined parameters
Author Response
Thank you for your suggestions and encouragement. In recent times, we have been carefully revising the paper, especially the abstract and conclusion sections. We are looking forward to your further suggestions.
Reviewer 2 Report
1. The English writing can be improved. The paper uses past tense everywhere, which is not appropriate. Grammar errors are also found (e.g., the first sentence of the introduction section).
2. The definition of water use efficiency (WUE) can be given earlier in the introduction section, and more detailed explanations of WUE should be given.
3. One claimed novelty of this paper is employing Geodetector method to study the spatial heterogeneity of WUE. Since Geodetector is not a very new method (it was introduced one decade ago), its merits for studying WUE should be more clearly stated.
4. In Figure 3, the time series plot of remainders still has a very clear periodic pattern. It seems that the seasonal component is not sufficiently modeled.
5. From Figure 4, we can see that the WUE values are largely missing in the western QM. Hence, the conclusions of WUE for QM region may be biased based on incomplete data.
6. On Page 3, Line 121, I am wondering why 46 data were obtained in a single year.
7. Regarding the Geodetector method, why did the authors only choose two detectors instead of using the total four detectors?
8. The q value measuring the spatial heterogeneity uses the variances in different subregions. I am wondering how the authors obtained those variances. Since the WUE values appear to have a strong spatial dependence, spatial correlations should be accounted for when computing the variances of WUE.
9. What are the implications of findings in this paper?
10. Punctuation mark should be added in the displayed formulas.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 3 Report
Dear authors
Please find comments on the manuscript “Spatio-temporal pattern and factor identification of vegetation water use efficiency in Qilian Mountains and Hexi Corridor, China” submitted to Remote Sensing journal.
Overall, I consider the text is good, however some aspects must be improved. Please improve introduction. I consider you can improve the presentation of the main issue to be solved. I also would like to understand better why you are using these regions for your study. Adding information related to the botanical composition (i.e., native species, crops, etc). In addition, I observed some minor errors related to the format. Please check the template con follow it. Also remember that every time you use a terminology for the first time you must name it completely and point into the abbreviation that will be used across the text.
Regarding figures and tables please include a footnote explaining what it means every single abbreviation what is used in the figure/table. Remember that the reader must obtain all information from the figure/table and not be redirected into the text to find the meaning of the abbreviation.
Major changes must be made in the conclusion section. You mainly provided results. In addition, one of my biggest concerns is that you are promoting your work as a reliable method, but you also provided sentences against your findings (i.e. MODIS quality). I will suggest minimizing these kinds of sentences and just add them in a single paragraph in the conclusions.
Abstract
Lines 12-13: importance is stated however is not described in the introduction why this is important.
Lines 15-16: add Google Earth Engine abbreviation GEE
Line 16: define what it means STL
Line 16: is Geodetector a model or a method, because in the introduction says that is a model?
Line 19: why WUE is expressed in kilograms of water rather than cubic meters or liters?
Introduction
Line 36: Define what is water use efficiency
Lines 37-38: this sentence seems to general, I do not see how this could help to understand carbon cycle from the soil reservoirs. Re write the sentence and try to be more specific providing a reason on how this helps to predict the effects on water and carbon cycles.
Line 38: add an “S’ to cycle.
Line 40 to 42: rephrase the sentence I think that would be easier to read as “Traditional biomass growth surveys and the study of ecohydrological processes are not suitable for short term analysis because they are time consuming and also due to the lack of precision”.
Line 42: before mentioning the eddy covariance method can quantify CO2, I strongly suggest to add a sentence mentioning that new technologies such as Eddy covariance stations can improve these studies.
Line 43: what do you mean by pulsation? Do you mean gradient? Please review and explain. Sentence is confusing.
Line 44; is Eddy covariance a method or an equipment?
Line 44 to 45: what results? No results have been shown or discussed yet. Strongly suggest to include previous results if you want to state their limitations.
Line 45: add a full stop after [5] and begin a new paragraph to describe remote sensing advantages.
Line 46: what do you mean with inversion? Please explain in detail
Line 48: define what is MODIS
Lines 53-54: rewrite the sentence as example “previous studies shown a significant spatial heterogeneity…
Line 60 add an “s” to Change
Lines 60 to 62: this sentence is confusing, as written I can understand that there are internal ecological processes involved. That is incorrect, the ecological process should be related to the external environmental circumstances. Please review and rephrase the sentence.
Line 64: add a final stop after [21,22].
Line 77: add “model” after Geodetector
78-83: Is it does not clear at all why the Qilian Mountains and Hexi Corridor regions are relevant for this research. Must provide more information related to the botanical composition present in these regions. Main species as a minimum Include information related to the social/political development. It is not clear why vegetation status affects agriculture or social stability, provide more background.
Line 81: Change Currently, study into Currently, “studies”.
Line 87: again, is Geodetector a model or a method? Please be consistent through the text.
Lines 89 to 92: remove the paragraph, does not provide any information relevant to your research, you are just stating the template you are following.
Materials and Methods
Line 110: how did you delineate the area?
Line 123: define what it means ET, GPP and LAI because seems the first time mentioned in the text.
Lines 125 to 127: provide brief explanation why you used these procedures.
Figure 2: please add under the figure what it means each one of the abbreviations used in the Figure.
Line 254: add a space after the period
Figure 8: fix the H2O, must be a subscript
Figure 14 check Y axis and include H2O
Lines 491-492: why are you mentioning human activities? This has not any relation with the whole text.
Lines 493-494: if Geodetector does not consider the spatial differences why did you use this model as a main axis of your research? Is there any other way to perform this research including the spatial differences? Why using only four zones for the analysis? Why not eight or twelve? Can the study be improved increasing the number of zones? Please, provided an attachment showing potential or null differences when including higher number of zones. This attachment can be added at the end of the paper.
Conclusions
Lines 87-89: you stated that your research “It also has important implications for the conservation of ecological environments and the wise use of water resources in this region.” However, the text lacks of any reference to conservation measures and improve the water resources use on the region. Please explain.
Conclusions must be written again. They are mainly results, they are not conclusions.
How is possible that Geodetector is effective on spatial variation when in line 495 you stated that you were not able to fully reflect the spatial heterogeneity? Also, you stated in line 485 that WUE estimation on this paper depends on MODIS reliability. Every research has some limitations, however, you are
References
Some references are provided using full journal name and others and using abbreviations. Use template and follow format.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Dear authors, the new manuscript presents substantial improvements after the reviewers suggestions. Thank you for considering the proposed improvements. best wishes
