A Worrying Future for River Flows in the Brazilian Cerrado Provoked by Land Use and Climate Changes
Round 1
Reviewer 1 Report
Review manuscript submitted to Sustainability - MDPI
A worrying future of the streamflows in the Brazilian Cerrado biome provoked by high rates of deforestation and climate changes
Salmona et al.
The manuscript propose to evaluate the impacts of deforestation and climate change in Cerrado biome, Brazil. The method described uses empiric and statistical model instead of hydrological processed based models. A brief discussion of why this method was chosen would be important. One major problem in this works as presented is that the main results of the manuscript contradict results published in the literature and there is no explanation or discussion around that. For this reason, I do not recommend this manuscript for publication as it is. Major problems are listed below.
1. A brief explanation of why the authors rather use the statistical approach and not the hydrological process based method would be important.
2. A comparison of the manuscript result with previous results from literature would be essential. The manuscript cite several other studies (19, 20, 22, 33 to cite some) that evaluate the impact of land use change and climate in different Cerrado regions however no comparison of results were done.
3. This manuscript results differed from most of the studies cited in the previous item. It is extremely important for the manuscript and strength of this method to discuss why the results are different. Most of these studies predict a decrease in Evapotranspiration and increase in river streamflow as result of deforestation that contradict the results of this manuscript.
4. The authors choose one Global Climate Model and one future scenario to investigate the impact of possible future climate change in their simulations. GCMs differ considerable between each other, it would be important to discuss why only one model was chosen and how representative this model is for future simulations. A set of different models and scenarios representing the possible different trends could give a more robust approach to the future climate simulations.
5. It was not clear how future land use was defined.
Author Response
Please, see the attached file.
Author Response File: Author Response.pdf
Reviewer 2 Report
The topic is meaningful and interesting. But there are some problems:
This MS only studies the effects of deforestation and climate changes. However, there are also some other factors that contribute to land use change. This needs to be explained and considered. Or use “land use” in the title? But this is only a suggestion. Based on this, how can you justify the impacts are from climate change?
The introduction section needs a logical adjustment. For example, L84-91: The introduction of water resources should be advanced, this is because it’s the theme of this paper. Then comes the analysis of the driving factors. L100-102: it is in one sentence, should not stand alone as a paragraph. L48-57: the introduction of crops is excessive and does not need to be divided into two paragraphs.
2.3. Future land use and climate change scenarios. There's too much detail in this part. Please delete some content.
Each image should be enlarged to increase readability.
In general, this MS describes too many algorithmic processes, but neglects to explain the results and discussion. In particular, there should be more analysis and discussion of the driving factors in the discussion part.
The conclusion is too long and a lot is suggested to move into the discussion part. The word number of conclusion is now over that of discussion. Therefore, it is suggested to shorten the conclusion to 1-2 paragraphs.
Author Response
Please, see the attached file
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
January 2023
Review manuscript submitted to Sustainability - MDPI
A worrying future of the streamflows in the Brazilian Cerrado biome provoked by high rates of deforestation and climate changes
Salmona et al.,
The manuscript propose to evaluate the impacts of deforestation and climate change in Cerrado biome, Brazil. The method described uses empiric and statistical model instead of hydrological processed based models. I appreciate the authors effort to respond to my comments. However one major problem in this works as presented is that the main results of the manuscript contradict results published in the literature and there is no explanation or discussion around that. It is still not clear in the responses or in the manuscript the issues I raised on my first review. Below are the 2 points that still worries me taken from the previous review.
2. A comparison of the manuscript result with previous results from literature would be essential. The manuscript cite several other studies (19, 20, 22, 33 to cite some) that evaluate the impact of land use change and climate in different Cerrado regions however no comparison of results were done.
3. This manuscript results differed from most of the studies cited in the previous item. It is extremely important for the manuscript and strength of this method to discuss why the results are different. Most of these studies predict a decrease in Evapotranspiration and increase in river streamflow as result of deforestation that contradict the results of this manuscript.
It is well known in the literature that deforestation under no changing climate tends to increase water flow in rivers. This is because the local vegetation evapotranspiration rates is larger then in an agricultural land cover, as consequence the exceedance of water goes to runoff. This result considering a no change in climate conditions, same precipitation, same temperature and so one, and considering same soil infiltration properties, if there is a deforestation there is an increase in runoff and so in rivers discharge. So looks like what is happening is that your manuscript is mixing different components. Are you in your data able to depict the impact of the different components? Maybe not if this is an statistical model approach isn’t your model a combination of several factors? If you can’t separate the components, the text in your manuscript should be reviewed, it must be clear what are the components combination that are causing the results you are presenting.
1) Deforestation: deforestation alone (with no shifts in climate) cause an increase in rivers discharge, well known in literature.
2) Climate Change: How historical or future climate change alone can affect river discharge?
3) Irrigation : How much historical irrigation have impact river discharge, any expectation of changes in irrigation to future? How much will it change rivers discharge?
4) What is the vegetation cover that is changing is it all same vegetation in all basin?
You say in the manuscript that ‘We estimated an average decrease of 8.7% and 6.7% on the streamflow due to deforestation and climate changes, respectively’. So if these refers to the individual contributions, yes your result disagree with the literature. That needs to be taken care of. What is the original vegetation you are referring to? So it looks a very extensive work but the results and conclusions need to be reviewed.
Author Response
Please, find attached our responses to Reviewer 1.
Author Response File: Author Response.pdf
Reviewer 2 Report
It is okay at this stage. Congratulations!
Author Response
Please, find attached our responses to Reviewer 2 comments.
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
The authors have included an extensive discussion on the contradictory results found on this study, that looks to be satisfactory instructive to the reader.