Application of Water Quality Indices, Machine Learning Approaches, and GIS to Identify Groundwater Quality for Irrigation Purposes: A Case Study of Sahara Aquifer, Doucen Plain, Algeria

Comment of Reviewer #1

Response

Reference

I find your paper "Application of water quality indices, multivariate modeling, machine learning approaches, and GIS to Identify Spatial Variability of Groundwater Quality for Irrigation purposes: a case study of Sahara aquifer, Doucen plain, Northestern Ouled Djelal, Alger" interesting and worth publishing in water.

There are a few things that need clarification/correction. My comments are as follows:

We are very grateful for your time, your positive outcome and for all your comments, as they have improved the text and helped to understand our study more properly.

We would like to take this opportunity to acknowledge the time and effort devoted by the reviewer.

Please find below our responses to each of your comments.

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1. Abstract, L 39-40: Please add information regarding the parameters. Is this line of a concentration decrease? The same comment applies to the conclusion, L 625-626.

1.We thank the reviewer for drawing our attention to this issue. As a consequence, more information regarding parameters was added in the abstract as well as in the conclusion, as suggested by the respected reviewer.

Line 42-44

Introduction

2. Introduction, L 59: Please explain, or rephrase "meteoric growth"

3. Introduction, L 61: Should not it read "km3"?

4. Introduction L 80: Refs 11-13 are better to be placed in the next paragraph (L 85-100), where all the statistical approaches are referred to. My suggestion is to replace them with the following 10.1016/j.ecolind.2020.106872; 10.1088/1742-6596/1960/1/012018; 10.1088/1742-6596/1960/1/012019, which better reflects the statement "interpret complex water quality data into simple terms"

2.Thank you for this comment. The sentence "meteoric growth" was rephrased and explained as suggested by the reviewer.

3. You are totally right, it’s Km3, we corrected it in the text as suggested.

4.We thank the reviewer for this recommendation. We would like to emphasize that all the authors agreed to add the recommended references (as well as other references). In addition, some references were corrected.

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5. Introduction L 88-93: Repetition of one and the same sentence.

5.We like to thank the reviewer for drawing our attention to this sentence. We deleted the second repetitive sentence as suggested by the reviewer.

Line 95-97

Materials and methods

6. In figs 1 and 2 the distance is expressed in miles, whereas in the text - in km. Could this be corrected?

7. Materials and methods - Paragraphs 2.11 and 2.1.2 can easily be moved to supplement since the paper's length is about 30 pages.

8.  Materials and methods, L 200: Please indicate that the laboratory is accredited under ISO/IEC 17025.

9. Materials and methods, L 202: Please rename paragraph 2.2.2. to "measurement of..."

10. Materials and methods, L 206: Please provide the instrumentation - type, model, producer, and country.

11. Materials and methods, L 207-208: Why did you not use EN 872? Is your method similar or the same? Yes it’s similar

12. Materials and methods, L 209: Please describe the method for the determination of nitrates.

6. We thank the reviewer for this comment. The two distances cited in the text and the figures were corrected. We changed the unit in the text to taking same unit as in the figs as suggested by the respected reviewer.

7. We agree with the reviewers’ comment. The paper’s length is more that 30 pages, we fixed it by moving some parts to “supplementary material” as suggested.

8. We thank the reviewer for drawing our attention to this issue. We corrected the name of the laboratory, and we added that the Lab was accredited ISO/IEC 17025.

9. We thank the reviewer for this comment. We renamed the subtitle of this paragraph as suggested by the reviewer.

10. Many thanks for this suggested. We added all the details and information about the method used to determine Nitrates as suggested by the reviewer.

11. Yes, this method is similar that the method: EN 872. Thank you for this comment.

12. We thank the reviewer for this recommendation. We added the description of this method as suggested by the reviewer .

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Line 232-234

Results and discussion

13. Results and discussion, L 340-342: Please rephrase "develop the following ways", it is not understandable.

14. Please check the correct formulae of the parameters (L 421, 471, 497).

15. Table 4, SAR: Number of samples - 100% maybe? It’s correct

16. Table 4, PI: Suitable - 0% maybe? It’s correct

17. Table 5, please stick to the already used format through the MS of the cations (e.g. Mg2+, instead of Mg++).

13. We thank the reviewer for this comment. We rephrased this sentence as suggested by the reviewer.

14.We checked the formula of this parameters and corrected all the mistakes.

15.Yes, it’s correct, as seen in the result displayed in Table 4.

16. We thank the reviewer for this remark. In Table 4, we used six methods in this paper and the results obtained for every method is different to others. In the discussion section, we tried to emphasize the best method between them.

17. We thank the reviewer for point this issue out. Corrected in Table 5 as suggested by the respected reviewer.

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Comment of Reviewer #2

Response

Reference

As-Salamu Alaykum Authors;

Groundwater is the backbone of sustainable development in arid and semi-arid regions of the world such as Sahara. In addition, aquifers support more than half of water needs for agriculture, industry and drinking purposes globally. Therefore, conservation of groundwater resources and their protection against the natural and anthropogenic pollution loads are required to support human life and environment during the Anthropocene. Frankly, I like the subject and believe the manuscript can be accepted for publication in Water after consideration of the following suggestions/modifications:

Wa alikoum salam.

We would like to emphasize that we appreciate your time, your positive response, and all of your suggestions, which have helped us enhance the content and better understand our study.

We would like to take this chance to thank the reviewer for their time and hard work.

Please find below our responses to each of your comments.

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 1- Title is too long.

1.      We thank the reviewer for drawing our attention to this issue. Title was shortened as suggested by the respected reviewer.

Line 2-5

Abstract

2- Abstract can start with a general problem statement instead of the specific objectives.

3- Line 38: Please do not use capital letter for “twenty”.

4- Abstract can end with some implications of the findings in a broader context. For example, what can others learn from your investigation? How can they apply your findings to their own study areas?

5- Keywords: Please do not use the Title words here, again.

2.      Thank you for this comment. Of course, we added general statement in the beginning of the abstract as suggested by the respected reviewer.

3.      Thank you for this comment, it was corrected it in the text.

4.       We thank the reviewer for this recommendation. We added the sentence that reflects the situation and the importance of our findings as suggested by the respected reviewer.

5.      Many thanks for this suggestion. We delated some keywords as suggested by the reviewer.

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Introduction

6- Please support this statement with appropriate references such as “Anthropogenic depletion of Iran’s aquifers”.

7- Introduction: The authors should place this work into a broader setting. The literature review does help in this regard. Please address the same regional studies aimed to investigate groundwater quantity and quality in arid and semi-arid regions of the world such as “Iran’s groundwater hydrochemistry”.

6.      We thank the reviewer for this recommendation. We added many appropriate references about the Anthropogenic depletion of Iran’s aquifers as suggested by the reviewer.

7.       We thank the reviewer for this recommendation. We agree with the reviewers’ comment. The authors found some appropriate references related to "Iran's groundwater hydrochemistry," that sought to learn more about the amount and quality of groundwater in arid and semi-arid parts of the world.

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Material and method

8- What do you mean by “limit area” in the legend of Figure 2?

9- I suggest the authors to move Figure 3 to SM.

10- Section 2.6 This section needs more references such as: “A framework development for predicting the longitudinal dispersion coefficient in natural streams using an artificial neural network”. ok

8. We meant the limit of the study area as indicated in the figure. In the new figure, we deleted “area” as suggested by the respected reviewer.

9.     We thank the reviewer for this recommendation. We agree with the reviewers’ comment. Consequently, we moved it in the supplementary materials.

10.     We thank the reviewer for this suggestion. We add this reference in the appropriate section as suggest the reviewer.

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Results and discussion

11- No need equations 5 and 6.

12- Discussion: I suggest the authors to extend this section by referring to the same studies conducted in the region and around the world such as “Iran’s groundwater hydrochemistry”.

11.  We totally agree, we deleted it from the manuscript as suggested.

12.  We thank the reviewer for drawing our attention to this issue. As a consequence, an additional paragraph concerning discussion was added as suggested by the respected reviewer. In addition, some important studies such as "Iran's groundwater hydrochemistry," were added in our study

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Comment of Reviewer #1

Response

Reference

you have substantially improved the MS and it is worth publishing in Water. Before that, there are still some minor corrections to be made:

Equation 6: CaX2, 2 should be subscript

We are very grateful for all your comments, as they have improved the text and helped to understand our study more properly. Please find below our responses to each of your comments. Regarding Eq.6 it was corrected as suggested.

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Table 3: Ca2+ instead of Ca++; Mg2+ instead of Mg++; in "SO4-2" 4 should be subscript and 2- instead of -2…..

Thank you very much for drawing our attention to these issues. Corrected as suggested.

Lines 520 to 521

Table 4, PI: the total number of samples is 27 for all the indices (IWQI, SAR KI Na%, MH and PI). Yet, in the classes of PI, the number is 39 (12+15+12). In the text (p. 21, L600-601), you state that "Approximately 55.55% of the water samples found in moderate class and the rest (44.44%) were unsuitable for irrigation", whereas 12 samples (44.4%) appear "Suitable". Should it not be 0 ?

Thank you for this comment. Corrected as suggested.

Lines 524 to 525

L564 KI<1 instead of KI 1  …..

Thank you for this remark. We agree with the reviewer, it was corrected as suggested by the respected reviewer.

Lines 564

P24-25, Fig. 10: Ca++ and Mg++ are still present and should be corrected to Ca2+ and Mg2+.

Thank you very much for drawing our attention to these issues. We corrected it as suggested.

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