Evapotranspiration Characteristics of Different Oases and Effects of Human Activities on Evapotranspiration in Heihe River Basin

Round 1

Reviewer 1 Report

The authors analyzed a high-resolution (100m) remote sensing dataset of ET over the Heihe River Basin to characterize the change of ET effected by human activities. I find the research question is meaningful. However, there are few technical questions that need to be addressed:

1. Please replace all the subplots (a), (b) ... in the figures with the respective date in their captions. I had a hard time looking back and forth between the figures and their captions.

2. Section 2.2. about the remote sensing of ET should be extended. The authors should write a separate paragraph about the detail of the ET product.

3. I need more explain from the results (i.e. why does the result look like this) throughout the manuscript. One example is in Figure 2, the authors didn't explain why the remote sensing data performed poorly in year 2015 at the Hunhenlin station.

4. In my opinion, few spatial figures could be combined or replotted for better interpretation. I still missed the difference in ET between each year for each region.

Author Response

Thanks the review for the valuable comments and suggestions. The reply to comments is  in the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors investigated the evapotranspiration (ET) over 2010-2016 in three oasis ecosystems in the Heihe River basin, China. They compared the in-situ ET data with those from the remote sensing data, and showed that remote sensing-based ET can well catch the variations of ET from the in-situ observational data. Furthermore, they also analyzed the spatial and temporal variations of ET for the three oases based-on the remote sensing data and discussed human being’s impacts. The study provides some valuable information. But, the result presenting and conclusions need major improvements.

Please see the comments as follows.

 

1.       It would be better to reorganize and rewrite the Abstract as current version does not provide interesting findings.

2.       Abstract part, line 19-20: the study period is only over 2010-2016, I think it is too short to analyze the “trend” of the three oases, therefore, the authors conclude that “Jinta oasis showed a decrease trend after 2012, while Ejina oasis showed a slight increase trend after 2014.” is quite misleading. And, “the inter-annual variation of evapotranspiration in Zhangye oasis was not significant.” is also confusing. How much variation? Like % of mean value? “not significant” could be “relative small”.

3.       Abstract part, line 25-26: “The evapotranspiration in urban and oasis areas is obviously different in summer and There was no obvious annual change for evapotranspiration in urban.” There is no scientific information from this kind of sentence. Why mention ET in urban here? How much difference between them?

4.       All figures should been presented more clearly.

5.       Figure 2 and lines 166-174, there is no quantitative descriptions about the accuracy of remote sensing data, compared to the in-situ data. How much is the meaning of “slightly higher”, “a small fluctuation”, “a large error in 2015”, “very high”? why not calculate the statistics as you were using “ME, RMSE, R”, or “NSE” or “bias in %”?

6.       Line 169, “At Daman station, there is a small fluctuation from March to May every year”, what is the meaning? When compare inter-annual variation, it is better to remove the seasonal cycle first.

7.       Line 255, “As can be seen from Figure 7, evapotranspiration of the three oases showed no obvious inter-annual change from 2010 to 2016”, it is better to present the relative change in % to the 7-year mean.

8.       As a larger percentage of ET could be from plant transpiration, it is highly meaningful to analyze relationship between the vegetation index (eg, NDVI or LAI) and the ET over the three oasis ecosystems.

9.       When discussing the urban expansion’s impact on ET, it is better to show the relative change of NDVI or LAI for the three oasis.

Author Response

Thanks the review for the valuable comments and suggestions. The reply to comments is  in the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Reconsider after major revisions

Comments for author File: Comments.pdf

Author Response

Thanks the review for the valuable comments and suggestions. The reply to comments is  in the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

There is still some tiny text editiing issues. Hope they can be rivised in the proof stage. 1) Line 30, "and There", delete "and"; 2) Table 3, R for Hunhelin being -0.91 is incorrect. Because the site data in 2015 is missing, we can only calculate R for 2014 and 2016. Authors need to recalcuate R for Hunhelin withour the 2015 data.

Author Response

Thank you for your valuable advice. We have made the modification in the revised manuscript. Please see the attachment for details.

Author Response File: Author Response.docx

Reviewer 3 Report

I found all the responses up to the mark and appreciate the efforts of the authors for improving the quality of the manuscript.

Author Response

Thank you again for your valuable comments and suggestions.