Spatiotemporal Changes in Evapotranspiration from an Overexploited Water Resources Basin in Arid Northern China and Their Implications for Ecosystem Management

Round  1

Reviewer 1 Report

This manuscript shows a very straightforward study of the spatiotemporal variation of ET over a watershed in China. The analysis seems to be consistent, but they are very simple.

I cannot see how this manuscript neither contributes to this journal nor the ET topic. MODIS data is available for any location in the world. Therefore we cannot consider this as a novel method. The analysis they authors do are trivial, and they fail in responding to some provocations they raise in the manuscript (such as “implications for ecosystem management”).

I understand that the authors had a good intention in submitting this manuscript, but they will only be able to overarch the objectives they want (starting from the title) if they consider other aspects than MODIS-ET and land-cover maps.

Author Response

Dear Reviewer:

Thank you for your careful reading, constructive suggestions, and kind comments on the above mentioned manuscript. 

        We made our best effort to improve the manuscript; changes were made according to your suggestions and comments. Please see our revision for detail.

Author Response File: Author Response.pdf

Reviewer 2 Report

It is an interesting study on ET changes in arid region in China. I have some concerns:

Why authors limited the study to period 2002-2012, why not exceed to more recent observations?

Could the show any comparison between remotely sensed data and data collected from the meteorological stations.

Can you show correlation between the ET relative changes of population and water consumption?

Author Response

Dear Reviewer:

Thank you for your careful reading, constructive suggestions, and kind comments on the above mentioned manuscript. 

        We made our best effort to improve the manuscript; changes were made according to your suggestions and comments. Please see our revision for detail.

Author Response File: Author Response.pdf

Round  2

Reviewer 1 Report

My first review of this paper was very general and highlighted the points for what I believe this paper should not be accepted. The authors rebuttal was focused on clarifying to me that the study has a broader scope than use MODIS products and that the use of the MOD3T dataset is novel for that watershed.

I would like to highlight that the simple use of the dataset is not novel. There are many ET datasets - right now the most famous in my opinion is GLEAM – that were not used to compare/validate the results. 

Another confusing aspect is that the authors are emphatic in saying that “As presented in the previous reply, our study did not only use MODIS ET. We also used the MODIS land cover map and a MOD3T product”. However, the authors clearly use the same dataset that they criticize as stated in their study as it is written in their manuscript: “The long-term ET data (MOD16, version 5) from 2002 to 2012 [23], with a spatial resolution of 1 km, provided by the National Aeronautics and Space Administration (NASA) was used for the spatiotemporal analysis.” and that the MOD3T was used in a complementary manner as stated in their manuscript: “Another ET dataset (MOD3T) … was used to compensate for the shortcomings of MOD16.”

This dataset (MOD3T) is an improved tentative in estimating the ET in some arid areas in China, but the authors try to sell its used by saying that this is disconnected from the MODIS data. Well, if one checks the source reference of MOD3T one find that “All input parameters [for MOD3T] except air temperature were obtained from MODIS datasets”.

My point is that the authors are facing the manuscript with equations and theories but they actually only used ready-to-use datasets. For that reason, I believe the paper was not submitted to a journal with a more technical approach in hydrology. For that same reasons, I’m confident that this manuscript does is not publishable because it lacks an approach that shows how the ecosystem services are being assessed. The authors, for example, state that “It is concluded that ET and its two components can provide an understanding of the connections between water and human society”. However, the study did not show anything about it.

I see this draft as a manuscript that is packing the straightforward use of two datasets and trying to sell it with jargons that cannot be further accepted in the area.

I advise the authors to focus in either the technical or ecological aspect of the study by focusing on the use and comparison of the MOD3T dataset for the region or really qualitatively and quantitatively assessing how a better ET estimate in the watershed can better estimate the ecosystem services in this area, respectively.

Author Response

Please see the attachment for details.

Author Response File: Author Response.pdf

Reviewer 2 Report

Big effort has been made to improve the manuscript. I recommend it for publication in Sustainability.

Author Response

Thank you for your positive evaluation and recognition of our work.