Water-Saving Scenarios Based on Input–Output Analysis and Virtual Water Concept: A Case in Iran
Round 1
Reviewer 1 Report
This paper presents a case study in Iran based on three water-saving scenarios. Using both input-output analysis and virtual water analysis, this study found ag contributes the most to water footprint and has great potential in saving water. While interesting and relevant to the journal’s readership, significant improvements are necessary before it can be published. My following comments help the authors improve the paper more efficiently.
Major Concerns:
Line 47-48, rephrase the sentence.
Lines 95-96, correct the reference error and add fig info. Also correct the errors in lines 177. You need to make corrections throughout the paper.
Line 124. For this section and other method section, you should mention any software or statistical procedures used for both input-output analysis and virtual water calculation.
Page 4, footnote 2. Citation is necessary for RAS method here.
Lines 299-300, you need to interpret the meaning of these multiplier values.
Results and discussion. Discussion is not appropriate. Regarding results of the three strategies, discussion is needed, in particular, you need to interpret the values, and compare with existing literature to see any new findings or consistency with other studies.
Most of the reference errors refer to tables or figures, I guess. While they are not showing, it is difficult to understand how values in tables are calculated.
Table 1. This table is technical coefficients and should be calculated according to eq (2). While it is assumed to be known in the equation. How the technical coefficients were calculated should be clearly presented.
Table 2. It shows the definition of sectors. The original values for each sector should be presented in the table (or data should be included in the appendix or supplemental data section.
Table 3. This table looks like results and should be included in the results section with appropriate interpretation and discussion. Calculation of water footprint associated with different sections (table 3) should be presented in detail. Either methods or discussion is missing, so the results (table 4-6) are clearly showing the water use and % changes, while how you got these changes are not clearly presented. Also insights on policy or management associated with each table are not clear.
Fig. 1. I think this figure shows the baseline results, and it should be presented in a first sub-section before presenting results of all three alternative strategies. Most equations presented in the above section are used to calculate the water footprint in this figure.
More literature review on input-output mode and virtual water estimation are necessary.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
I think you did an acceptable and useful empirical work. The process seems sound, although not easily replicable. The theoretical part is a little bit confusing and too long taking into account that almost all is a well-known methodology. All in all, I think it could be published, although with a big deal of changes.
These changes affect, essentially, to the materials and methods and results sections. The general idea is to focus in the framework used to carry out the three water saving scenarios. As it now stands, the method used to obtain the results is not clear. You devote a lot of space in explaining the construction of the tables but much less to the (supposedly) common framework in which you perform your simulations. Well, I do think that this has to change: you have to show clearly how you use Input-Output framework to obtain your results.
You have to realize that the need of using such a framework steams on its ability to: i) simulate changes in technical coefficients, exports-imports and the mix of crops and, ii) obtain results in terms of income, added value and employment in the economy as a whole. The way you are now explaining it, it seems that changes in technical coefficients or in the crops can be done ‘outside’ the box of the I-O framework. You have to clearly unify your calculation framework and, at the same time, put a unique and thorough template for showing the results.
The way as it is now, one has a hard time to compare the results of every scenario, which are ‘thrown’ in the text here and there and shown in tables with different variables and structure. The most important part of the results is that comparison of the scenarios. The fact that agriculture is a key sector for any change in the water management does not need Input-Output tables or any virtual water analysis: is self-evident. A common framework (table) should be presented so as one can compare the results in terms of value added and employment of every scenario. The difficulties in the implementation of these scenarios are a separate question. There is no problem that this important issue appears in the discussion section. But I think that it should be treated in a separated sub section, once the results of the application (that is, the real contribution of the paper) have been clearly settled.
Minor changes
First, in my copy appears many times across the text the message: Error! Reference source not found. Fix this
Page 1 line 44: Allan did not introduce this concept in this reference but in a later one. By the way, the concept of embedded water or embedded whatever is much more previous. Allan simply popularized it under the term virtual water in 1998. There are hundreds of papers which have done essentially the same as you did in this paper. Almost all of them cite the seminal works in this field. Simply pick one of them and cite appropriately those seminal works that probably appear in it.
Page 2
Line 67: the water utilization efficiency is not a question of input-output, it is s previous one (technology, etc.). The main question is the following you mention: trace the intersectoral ‘movement’ of water.
Line 74 nonsurvay methods?
Page 7, line 213: This Company could be a very good data provider, but there is no way of replicating the study nor is a proof of the quality of the data set.
Page 8 Table 3: The final column (Final sectoral water multiplier) would be the ratio between this column and the second (direct water consumption). That’s what a multiplier means.
Page 8, lines 237-238: I think you wanted to say other thing: that it is very reprehensible any misusage in agricultural sector.
Pages 10, 11: As I mentioned above, Tables 5-7 should have a common structure I order to be compared. The numbers about employment and added value should also be shown in these new tables instead of being spread across the text.
Author Response
Please find the attached file.
Author Response File: Author Response.pdf
Reviewer 3 Report
The article ‘Water saving scenarios based on IO Analysis and VWC: A case study in Iran’ presents a preliminary study on optimal water use assessment in the region of South Khorasan in Iran. The evaluation has been carried out combining IO model and the VWC to assess 3 different scenarios of water saving among which adopting a proper crop pattern seems to be the most effective. The problem of water saving and the application of IO model and VWC is up to date and really interesting, however methodology needs to be clarified, especially to better explain the three case studies. Thus, I suggest a major revision in order to improve the methodological description and highlight the hypothesis and the implications of each of the three scenarios considered. Unluckily, not all the references correctly appear in the version of the manuscript I had, so I will suggest the authors to check them and to provide additional literature review, especially in the introduction. Finally, I will suggest to move some parts of the introduction and results in the method section, as better specify in the detailed comment, in order to simplify the comprehension of the text.
Major comment
Line 220-229
To which year/s climatic data refer to?
Which soil type/s has/ve been used?
Paragraph 3.1
Please, describe the way in which a 10% increase in water productivity can be reached?
Are we speaking of green/blue or total water required by crops?
Which is the relation between water used in agriculture and water productivity? Is it simply a linear relation? Please, explain it better
Table 5. How do you obtain the value in table 5? Please, explain it better.
Paragraph 3.2
To which item/agricultural commodities it is applied the reduction in export and increase in import?
How do you justify an increase in import if you decide to export 10% less? There will not be more food/crops available domestically? Which is the rationale behind this scenario?
Paragraph 3.3
Which are the hypothesis behind this scenario? Keeping constant the harvested area and replacing the different crops based on their water footprint? Is the soil type and soil texture good for all crops in the same way? Is climatic condition and rainfall patterns good as well?
Line 316. Why fruit crops are not mentioned here?
Conclusion
Which are the main limits of the model/ indicators that you used?
Minor edits
Line 37 cit. missing
Line 43 cit. missing
Line 48. Add citations
Line 71-83 move to the method section
Line 94-108 cit. missing
Line 133. Considerations ARE used
Line 224. Cit. missing
Line 242-253 move to method section- case study description
Figure 1a. Please, correct the axis – it is not immediate the scale used
Table 6 caption. How a 10% decrease in the final demand is associated with a change in variation in import/export?
Author Response
Please find the attached file.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The paper has been significantly improved and can be accepted for publication.
A minor comments:
Line 99, is that "consequently"?
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
I think that you did the best you could to address my criticisms-concerns. Now I understand better what you did/wanted to say. Two questions remain.
Let’s start by the minor one. In my first review I wrote: “Line 67: the water utilization efficiency is not a question of input-output, it is a previous one (technology, etc.). The main question is the following you mention: trace the intersectoral ‘movement’ of water.”
Your answer:
The authors thank the reviewer for his/her concern. The ‘efficiency’ and ‘effectiveness’ here refer to the economic efficiency of different sectors. That is, the volume of water inputs to a specific sector per the monetary output of that sector. In other words, the water utilization efficiency is assessed through the economic analysis in light of IO model.
Efficiency generally means a ratio between resources and results in obtaining a specific final end. That’s why this word seemed unappropriated to me in that context. For the comparison you made implies the quantity of water per monetary value of the production of very different sectors. I now understand what you wanted to say by water utilization efficiency and I think it would be better phrased under “apparent water productivity” (or its inverse). Let me show you an example: you can use very inefficiently water in the production of diamonds, but that would be very ‘efficient’ in your framework.
A slightly mayor issue but probably beyond the possibilities of this paper: Since virtual water is no more that the direct plus indirect water contained (embedded) in exports/imports, it has nothing new or different with respect to the embedded water calculated by way of the IO table. As a consequence, the comparisons between scenarios could be equally performed. After all, what does a substitution of local production by imports mean? I answer myself: that you are putting zeroes in some parts of your input output table and some positive numbers in the import vector. True, the socio-economic implications of this change go far beyond this ‘cold’ procedure. But you have to understand that there is no difference between both approaches. In an ‘ideal’ world, you could import all the agricultural commodities from abroad. It is very understandable that such scenario is not feasible even in the medium run, but it is the way your calculations show. And, by the way, it is the main contribution of the ‘virtual water’ literature. Against this background, you should not have difficulties in comparing the value added – employment in all the scenarios in a common framework. A different question is the feasibility of the changes it eventually implies. Your current text somehow explains this dilemma, but I think in a slightly confuse way.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
I’m satisfied with authors reply to my first comment.
Author Response
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Author Response File: Author Response.pdf
