Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript presents a relatively well-written and logically structured study. A particularly commendable feature is its holistic approach to assessing regional water use, integrating both environmental and economic outcomes. This comprehensive perspective is valuable for informing sustainable water management strategies and guiding regional policy decisions.

Strengths

• The manuscript adopts a holistic framework for valuing water use, incorporating environmental impacts through net carbon emissions using a life cycle assessment approach across various sectors within the region. This dual-focus enhances the practical relevance and applicability of the study’s findings.
• The logical flow of the manuscript is generally sound, with a clear progression from the introduction of the research problem to the methodology, results, and conclusions.
• The study involves extensive computation and data analysis, providing strong support for the conclusions drawn.

Aspects for Improvement

1. Presentation of Total Regional Water Use
   The manuscript would benefit from the inclusion of a comprehensive, tabulated summary of total regional water use. A well-structured table consolidating key figures would improve the readability and transparency of the results section, enabling readers to better appreciate the scale and distribution of water consumption across different sectors and uses.
2. Language and Grammar
   While the manuscript is generally understandable, the English language and grammar require further refinement to enhance clarity and fluency. I recommend that the authors carefully proofread the text or consider professional language editing services to address occasional awkward phrasing, grammatical errors, and terminology inconsistencies.

Specific examples illustrating these issues:

• Lines 179–181:
  “Studies have shown that economic value modeling enhances resilience against water scarcity by optimizing resource distribution under conditions of uncertainty and climate change.”
  This sentence lacks clarity. A clearer alternative would be:
  “Research shows that using economic models to value water use helps build resilience to water scarcity by improving how resources are distributed under uncertain conditions and a changing climate.”
• Lines 183–185:
  “Additionally, these models facilitate conflict resolution by providing transparent and equitable allocation mechanisms, as evidenced by applications in transboundary river basins where shared water resources are subject to international disputes.”
  If this reflects the authors’ intended meaning, consider revising to:
  “Additionally, these models support conflict resolution by providing transparent and fair allocation mechanisms, as demonstrated in transboundary river basins where disputes over shared water resources are common.”
• Lines 187–188:
  “The model analyzes the agricultural, industrial, urban, recreational and environmental water demands. All economic values are adjusted for inflation in Spain.”
  It would be clearer to revise this as:
  “The analysis evaluates agricultural, industrial, urban, recreational, and environmental water demands. All economic values are adjusted for inflation in Spain.”
  Since a model itself does not ‘analyze’; rather, it is used to analyze.

Conclusion

Overall, this manuscript makes a valuable contribution to the field of regional water resource assessment. Addressing the points outlined above—particularly the inclusion of a total regional water use summary and refinement of the language—would further strengthen the manuscript and enhance its overall quality, clarity, and impact.

Comments on the Quality of English Language

While the manuscript is generally understandable, the English language and grammar require further refinement to enhance clarity and fluency. I recommend that the authors carefully proofread the text or consider professional language editing services to address occasional awkward phrasing, grammatical errors, and terminology inconsistencies.

Specific examples illustrating these issues:

• Lines 179–181:
  “Studies have shown that economic value modeling enhances resilience against water scarcity by optimizing resource distribution under conditions of uncertainty and climate change.”
  This sentence lacks clarity. A clearer alternative would be:
  “Research shows that using economic models to value water use helps build resilience to water scarcity by improving how resources are distributed under uncertain conditions and a changing climate.”
• Lines 183–185:
  “Additionally, these models facilitate conflict resolution by providing transparent and equitable allocation mechanisms, as evidenced by applications in transboundary river basins where shared water resources are subject to international disputes.”
  If this reflects the authors’ intended meaning, consider revising to:
  “Additionally, these models support conflict resolution by providing transparent and fair allocation mechanisms, as demonstrated in transboundary river basins where disputes over shared water resources are common.”
• Lines 187–188:
  “The model analyzes the agricultural, industrial, urban, recreational and environmental water demands. All economic values are adjusted for inflation in Spain.”
  It would be clearer to revise this as:
  “The analysis evaluates agricultural, industrial, urban, recreational, and environmental water demands. All economic values are adjusted for inflation in Spain.”
  Since a model itself does not ‘analyze’; rather, it is used to analyze.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

* Abstract and Introduction

1. In the abstract part of the paper, phrase such as “achieving an optimal balance” could be rephrased to better reflect the characteristics of modeling results. Additionally, the introduction would benefit from a more detailed explanation of how this study advances beyond previous models.

 

* Methodology

2. More explanation for how Spain’s emissions factors for electricity were derived and validated for each water source and sector is needed.
3. It would be valuable to include a brief sensitivity analysis or discussion on how different parameter choices could influence the outcomes.

* Results

4. More clarification is needed regarding the high carbon intensity of desalination and how this influences long term policy decisions under climate uncertainty.

* Conclusion

5. The results of this research depend on local hydrological and economic variables. Addition of more general discussion on the limitations and potential of the suggested models is encouraged.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript presents a comprehensive and innovative framework integrating CO₂ emissions modeling with economic valuation to address sustainable water management in the Segura River Basin. The study is timely, given global water scarcity challenges, and offers actionable insights for policymakers. The methodological rigor, clear structure, and relevance to regional and global contexts are strengths. However, some areas require clarification or improvement to enhance readability, reproducibility, and impact. Here are some comments.

[1] While references are provided, some datasets (e.g., CO₂ sequestration rates for crops) lack transparency. Include supplementary material or appendices with raw data or calculation steps.

[2] Clarify assumptions in economic curves (e.g., non-linear relationships in urban water demand) and sensitivity analyses to validate robustness.

[3] Figure 1: The caption mentions a spatial distribution map, but the figure is not included in the provided text. Ensure all referenced figures are available.

[4] Figure 5: CO₂ emissions per hm³ by sector—consider adding error bars or confidence intervals to show variability.

[5] Tables 1–6: Provide units consistently (e.g., "t CO₂/ha-year" vs. "kg CO₂/m³").

[6] Emphasize intra-sector variability (e.g., high-value vs. low-value crops in agriculture) and its implications for policy.

[7] While mentioned, the study could better address how projected climate scenarios might alter water availability and emissions.

[8] Expand on why desalination remains critical despite its inefficiency (e.g., drought resilience).

[9] In Abstract, simplify the final sentence for clarity: "This approach guides sustainable water allocation in water-scarce regions."

[10] In Section 4.3: The term "Enviromental" contains a typo; correct to "Environmental."

[11] Define all abbreviations at first use (e.g., "ADU" in the abstract).

[12] Ensure all in-text citations match the reference list (e.g., [22] is cited before its full reference appears).

Author Response

Please see the attachment.

Author Response File: Author Response.pdf