Agricultural Water Security under Climate Change in the Iberian Peninsula
Round 1
Reviewer 1 Report
Title
The Title reflects the paper’s content accurately.
Abstract
The Abstract determines the paper’s content and objectives in a very manifest and complete fashion.
- Introduction
Start off L42 with the sentence “Agriculture contributes the largest share of global methane and nitrous oxide emissions. Most of its methane emissions is produced by enteric fermentation during the digestive processes of ruminant animals, and by rice cultivation. The nitrous oxide emissions originate mainly from the application of nitrogen-based fertilizers and animal manure management” verbatim from [1] p. 39. In L42-L43 “Agriculture contributes to approximately 20% of the global emissions of greenhouse gases ” should be rephrased as “Agriculture is the global primary water stakeholder in terms of withdrawals (70% of withdrawals and 92 % of global fresh water consumption) [2] as water is considered to be an input endowment clearly favoring agriculture vis-à-vis industry [3] while contributing to approximately 20% of the global emissions of greenhouse gases”. This 20% is based on the 2000 source [7] cited, consult a more recent source e.g. [4] for more up to date data. Otherwise well written and informative.
- Materials and Methods
2.1. Study area
A very good description.
2.2. Copernicus datasets
The choice of RCP8.5, which tracks CO2 quite well [5], is reasonable and the choice of variables is optimal. In L98 correct the typo “as follow” to “as follows”. The selection of the particular LCs is justified.
- Results
3.1. Land Cover and Normalized Difference Vegetation Index change
Both Figures 2 and 3 are highly descriptive, the interpretation of Table 1 is justified and so is the segmentation of NDVI seen in Gig. 3 and Table 2.
3.2. Bioclimatic indicators
Correct but in Figures 5, 6, 7, 8 and 9 there is no (f).
- Discussion
Quite exhaustive, analytical and in depth and well sourced.
- Conclusions
Firmly based on the previous sections.
References
[1] FAO, The future of food and agriculture: Trends and challenges. Rome, Italy: Food and Agriculture Organization of the United Nations, 2017. [Online]. Available: https://www.fao.org/3/i6583e/i6583e.pdf
[2] Zisopoulou, K., D. Zisopoulos, and D. Panagoulia, “Water Economics : An In-Depth Analysis of the Connection of Blue Water with Some Primary Level Aspects of Economic Theory I,” Water (Switzerland), vol. 14, 2022, doi: https://0-doi-org.brum.beds.ac.uk/10.3390/w14010103.
[3] FAO, The State of Food and Agriculture: Climate Change, Agriculture and Food Security. Rome, Italy: Food and Agriculture Organization of the United Nations, 2016.
[4] Schwalm, C. R., S. Glendon, and P. B. Duffy, “RCP8 . 5 tracks cumulative CO 2 emissions,” PNAS, vol. 117, no. 33, pp. 19656–19657, 2020, doi: 10.1073/pnas.2007117117.
Author Response
The authors are very grateful to the reviewer for his/her encouraging comments and valuable suggestions. We do believe these comments have contributed to improving the overall quality and impact of our study. Please see the attached document with the replys to each comment.
Kind Regards.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In general, the study results are of scientific and practical interest. Before I recommend the manuscript for publication, authors should consider the following remarks.
- I did not find an explanation in the manuscript for why the years 1990 and 2020 were chosen to assess land-cover changes in the studied river basins. How much does the difference in the area under the five crop categories between these two years reflect the general course of evolution over the past 30 years? The authors should more carefully substantiate this and convince the reader of the reliability of the identified trends.
- In the Discussion section, it would be much more helpful from a practical point of view to explain and give general recommendations regarding adaptation to future climate change for not the entire Iberian Peninsula but for each of the five river basins studied. These river basins have different physiographic features and will respond differently to temperature and precipitation changes in the future. Otherwise, I don't understand why you studied land-cover dynamics within individual river basins and then did not use this information in any way in the discussion and conclusions regarding adaptation to climate change. One gets the impression that these are two unrelated studies.
In addition:
- What are the units of measurement in Table 1?
- Line 222. “… 0.06 and 0.12 for both P2 and P3…”. Are you setting the values too low?
- Line 241. “… an increase in temperature associated with a decrease in precipitation…”. What exactly makes you think that way and not vice versa?
- Perhaps more logical is the following title of the manuscript – “Agricultural land use and water security in the face of climate change in the Iberian Peninsula” or “Agricultural water security in the face of climate change in the Iberian Peninsula”
- In Keywords, please do not use the same words and phrases as in the title of the manuscript.
- Instead of “Corine land cover”, please write “CORINE land cover”.
- Aridity index (in mm/mm). What did you mean?
- Delta (mm/mm). What did you mean?
- Volumetric soil water in layer 1 (in mm3/mm3). What did you mean?
Author Response
The authors are very grateful to the reviewer for his/her encouraging comments and valuable suggestions. We do believe these comments have contributed to improving the overall quality and impact of our study. Please see the attached document with the replys to each comment.
Kind Regards.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
I'm still not satisfied with the authors' response to one of my previous comments:
MY COMMENT: Line 241. “… an increase in temperature associated with a decrease in precipitation…”. What exactly makes you think that way and not vice versa?
YOUR RESPONSE: R: As denoted in figures 5 and 6, the climate signal shows an increase of temperature and decrease of precipitation for the entire area. Moreover, Figures 5d and 5e and figures 6d and 6e show the variation for both P2 and P3 and positive and negative values are observed for temperature and precipitation respectively.
My question was not about opposite trends in air temperature and precipitation. My complaint was about the logic that follows from your sentence. According to this logic, the noted decrease in precipitation was the cause of the noted increase in air temperature. That's why I asked, why do you think that this is so, and not vice versa? The relationship between changes in air temperature and precipitation is a complex process. In this case, you need to either explain it somehow in the sentence or change its construction.
Moreover, instead of "temperature," write "air temperature" (where it refers to atmospheric air).
Author Response
The authors are very grateful to the reviewer for his/her comments and suggestions. Please see the following text with the authors response.
Kind Regards.
Author's Reply to the Review Report (Reviewer 2)
MY COMMENT: Line 241. “… an increase in temperature associated with a decrease in precipitation…”. What exactly makes you think that way and not vice versa?
My question was not about opposite trends in air temperature and precipitation. My complaint was about the logic that follows from your sentence. According to this logic, the noted decrease in precipitation was the cause of the noted increase in air temperature. That's why I asked, why do you think that this is so, and not vice versa? The relationship between changes in air temperature and precipitation is a complex process. In this case, you need to either explain it somehow in the sentence or change its construction.
Moreover, instead of "temperature," write "air temperature" (where it refers to atmospheric air).
R: The authors apologize for misunderstanding the reviewer question. Now it is clearer and we agree with the reviewer. We did not mean to establish a cause-effect relationship between air temperature and precipitation, but rather mentioning the synergy between the trends of these two climate variables. We changed the text accordingly.
Line 250 -251: “The scenarios hint at a combination of an increase in air temperature with a decrease in precipitation…”
