Hydrogeochemical and Stable Isotope Data of the Groundwater of a Multi-Aquifer System in the Maknessy Basin (Mediterranean Area, Central Tunisia)
, Khyria Wederni 1,2, Naima Hidouri 2,4, Monji Hamedi 5, Zahra Dhaoui 6 and Younes Hamed 2,7
Round 1
Reviewer 1 Report
Manuscript ID: hydrology-2153620
Title: Hydrogeochemical and stable isotope data of groundwater of a multi-aquifer system of Maknessy basin (Mediterranean area, central Tunisia)
by Zouhour Moussaoui, Matteo Gentilucci, Khyria Wederni, Naima Hidouri, Monji Hamdi, Zahra Dhaoui and Younes Hamed
Written evaluation
Overall impression and recommendation
The manuscript investigates groundwater quality in central Tunisia, using chemical, isotopic and statistical techniques. The paper is generally well structured, the data is good, but it is unfortunately poorly written. There are many concerns which need to be addressed as stated in general and specific comments bellow.
General comments
1) language editing required
I noticed many grammatical errors in the paper, such as the word order, use of articles, singular and plural, and tenses of verbs. I, therefore, recommend that authors double-check their grammar, ask their native English-speaking colleague to assist to check grammar, and/or use the English editing service to ensure that it is meet the standard of publication. Some of the observed errors will be mentioned through specific comments.
2) too long sentences, unclear meaning
There are many too long sentences in which the meaning is lost. Some of them will be stated in specific comments, but in general, if a single sentence stretches across 4-5 lines, it is too long. The Introduction section is a typical example of how it should not be written. Please pay attention through the entire text and revise those sentences accordingly - divide the sentences into several, read them with understanding and ensure that they make sense.
Specific comments
1. Lines 27-28: rephrase the sentence, there aren’t three types of GW quality
2. Line 31: …influencing water quality. (the rest of the sentence not needed)
3. Lines 32-33 and the rest of the paper: please round δ18O to two, and δ2H to one decimal place.
4. Line 33: SMOW is not a reference material. Please use VSMOW2.
“VSMOW2 (Vienna Standard Mean Ocean Water 2) is an primary measurement standard for stable isotope analysis. This water material was prepared at the IAEA Isotope Hydrology Laboratory in 2006 to replace the exhausting VSMOW material.” (https://nucleus.iaea.org/sites/ReferenceMaterials/Pages/VSMOW2.aspx)
5. Line 34-36: Please check sentence, unclear
6. Line 41: …used quality? Do you mean quality of the used water?
7. Line 80-85: unclear sentence, …that are useful to identify…?
8. km2 – add superscript
9. Figure 1: Change font color – black letters on green background do not work; Faults should be in red color; Graphical scale not clear; move the arrow that it does not cover the grid numbers (3900000)
10. Line 112 – add reference to Figure 1
11. Lines 112-115: If you use sentence to elaborate Triassic outcrops, then probably stratigraphic series starts from Triassic, not from Cretaceous.
12. There is no reference on Figure 2 within text.
13. Lines 128-139: It seems that this entire paragraph is from reference 36, which is stated several times. Please rephrase the text
14. Line 148: is the meaning of flow rate actually pumping rate?
15. Lines 150-151: Upper Zebbag aquifer is repeated.
16. Line 154: What is the good test?
17. Line 159: Please add those cold springs in the Figure 3.
18. Figure 3: increase the font where possible (if not possible, remove the boxes with TDS). What are the numbers above boreholes? Add scale below 200 m to the bottom of your aquifer system. Is the altitude in (m a.s.l.)? What is biological agricultural? Change font color – black letters on brown background do not work. Climatic parameters – should P also be in mm/year, as ETP?
19. Line 172: for in situ measurements?
20. Line 186: use formula, rather than figure for equation; add (1) as this is equation
21. Lines 188-189: nitrate and salinity repeats
22. Table 1 is result, it should not be in Materials and Methods!
23. Table 1: Round up to a same number of decimal places accordingly, e.g. why is Na+ in two, but Ca2+ with one decimal place? In my opinion, this table should be in supplementary material; if a table spans through several pages, every page should have table title and heading
24. Figure 4: What is locality in this figure? Also, networek – network
25. Section 5.2.: this section is unnecessary in my opinion, these are the basic methods that are commonly used for representations of hydrochemical types. However, if you decide to leave this part, here are my comments: Piper’s diagram is not used in modelling; it hasn’t been recently used, it is commonly used; if you say that it is used in many studies, please add those studies (not just two); which software was used for Piper? Lines 200-207 is too long for 1 sentence!
26. Lines 214-215 and further: PCA is Principal Component Analysis
27. Lines 219-220: Please check sentence, I don’t understand
28. Line 249: The sentence starts with small letter
29. Table 2: Line numbers overlap with the table; change decimal places, 3 are certainly not needed
30. Lines 288-293: check commas, capital letters
31. Lines 326-331: If Line 186 is equation (1), then move these equations from 2-7
32. Figure 8: increase the font where possible; use decimal point, not comma; what are the meaning of red arrows in Figure 8c)?
33. Line 342-243: … many quantity of organic fertilizers to double their yields… please rephrase. Maybe like: …overuse organic fertilizers to increase their yields…?
34. Line 350: nitrite is NO2-!
35. Lines 374-375 and 403: use decimal points
36. Lines 376-383: too long sentence, meaning is lost
37. Lines 411-412: repeating
38. Lines 415-420: too long sentence
39. Figure 10a): parameter names overlap the dendrogram
40. Line 447: None of the samples are at RMWL, all of them are below the line
41. Line 450 and further: Global Meteoric Water Line abbreviation is GMWL
42. Line 455: use 2 decimal places for d-excess
43. Lines 462-463: round δ18O to two, and δ2H to one decimal place; use VSMOW2
44. Line 480: d-excess repeating
45. Line 483: Use superscripts, check sentence
46. Line 491: point, comma, capital letter - modify
47. Lines 491-495: check sentence, seems like random text
48. Table 5: Line numbers overlap with the table; change decimal places δ18O to two, d-excess to two, and δ2H to one decimal place
49. Conclusion is poorly written, seems like random text:
Lines 523-524: its-its-its repeating
Line 525-529: verb missing; what is the free layer? Too long sentence
Line 530: Statistical methods do not control chemistry, they can indicate something etc.
Line 530-536: too long sentence, meaning is lost
50. Line 551-552: revise-d; manuscriptd
51. Author Contributions and Conflicts of Interest: The last sentence is repeating.
Author Response
Written evaluation
Comment 1: Overall impression and recommendation
The manuscript investigates groundwater quality in central Tunisia, using chemical, isotopic and statistical techniques. The paper is generally well structured, the data is good, but it is unfortunately poorly written. There are many concerns which need to be addressed as stated in general and specific comments bellow.
Response 1: We thank the Reviewer 3 for this valuable and useful comment. Agree with this comment and all corrections will be marked in red colour.
General comments
The manuscript investigates groundwater quality in central Tunisia, using chemical, isotopic and statistical techniques. The paper is generally well structured, the data is good, but it is unfortunately poorly written. There are many concerns which need to be addressed as stated in general and in specific comments below.
Comment 1: language editing required
I noticed many grammatical errors in the paper, such as the word order, use of articles, singular and plural, and ten ses of verbs. I, therefore, recommend that authors double-check their grammar, ask their native English-speaking colleague to assist to check grammar, and/or use the English editing service to ensure that it is meet the standard of publication. Some of the observed errors will be mentioned through specific comments.
Response1: We thank the Reviewer 3 for this valuable and useful comment. Agree with this comment and all corrections will be marked in red colour.
Comment 2: too long sentences, unclear meaning
There are many too long sentences in which the meaning is lost. Some of them will be stated in specific comments, but in general, if a single sentence stretches across 4-5 lines, it is too long. The Introduction section is a typical example of how it should not be written. Please pay attention through the entire text and revise those sentences accordingly - divide the sentences into several, read them with understanding and ensure that they make sense.
Response 2 We thank the Reviewer 3 for this valuable and useful comment. Agree with this comment and all corrections will be marked in red colour.
Specific comments
Comment 1: Lines 27-28: rephrase the sentence, there aren’t three types of GW quality
Response 1: We thank the Reviewer 3 for this valuable and useful comment. I accept your comment; you can see the laundry correction 27-28
Comment 2: Line 31: …influencing water quality. (The rest of the sentence not needed)
Response 2: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment I fixed the sentence
Comment 3: Lines 32-33 and the rest of the paper: please round δ18O to two, and δ2H to one decimal place.
Response 3: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment I round δ18O to two, and δ2H to one decimal place Line 31-32
Comment 4: Line 33: SMOW is not a reference material. Please use VSMOW.
“VSMOW (Vienna Standard Mean Ocean Water) is a primary measurement standard for stable isotope analysis. This water material was prepared at the IAEA Isotope Hydrology Laboratory in 2006 to replace the exhausting VSMOW material.”(https://nucleus.iaea.org/sites/ReferenceMaterials/Pages/VSMOW2.aspx)
Response 4: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I used VSMOW see line 31-32
Comment 5: Line 34-36: Please check sentence, unclear
Response 5: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the line correction 33-35
Comment 6:.Line 41: …used quality? Do you mean quality of the used water?
Response 6: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I corrected it is the quality of water sees line 40
Comment 7: Line 80-85: unclear sentence, …that are useful to identify…?
Response 7: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the correction Line 79-84
Comment 8:.km2 – add superscript
Response 8: We thank the Reviewer 3 for this valuable and useful comment; I put square km2 by exhibiting
Comment 9: Figure 1: Change font color – black letters on green background do not work; Faults should be in red color; Graphical scale not clear; move the arrow that it does not cover the grid numbers (3900000)
Response 9: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the correction in figure 1
Comment 10: Line 112 – add reference to Figure 1
Response 10: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, the figure is extracted at the scale of a geological map: 1/500,000
Comment 11: Lines 112-115: If you use sentence to elaborate Triassic outcrops, then probably stratigraphic series starts from Triassic, not from Cretaceous.
Response 11: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I have correlated lithostratigraphic outcrops in the study area have a stratigraphic series from the Triassic to the Quaternary line 110-110
Comment 12: There is no reference on Figure 2 within text.
Response 12: We thank the Reviewer 3 for this valuable and useful comment; I accept your remark, the reference in figure 2 is Ouda, B. Isotopic palaeohydrology of the Maknassy Basin (Central Tunisia) during the Quaternary recent. Doctoral Thesis, Faculty of Sciences of Tunis, 234p.Master of Science Faculty of Sfax, University of Sfax, 121p. 2000
Comment 13: Lines 128-139: It seems that this entire paragraph is from reference 36, which is stated several times. Please rephrase the text
Response 13: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the laundry correction 127-135
Comment 14: Line 148: is the meaning of flow rate actually pumping rate?
Response 14: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, the meaning of the flow is the pumping flow
Comment 15: Lines 150-151: Upper Zebbag aquifer is repeated.
Response 15: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I cancelled the rehearsals
Comment 16: Line 154: What is the good test?
Response 16: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the correction to the cloth 149-151
Comment 17: Line 159: Please add those cold springs in the Figure 3.
Response 17: We thank Reviewer 3 for this valuable and useful comment; I accept your comment, I have added the cold source in figure 3
Comment 18: Figure 3: increase the font where possible (if not possible, remove the boxes with TDS). What are the numbers above boreholes? Add scale below 200 m to the bottom of your aquifer system. Is the altitude in (m a.s.l.)? What is biological agricultural? Change font color – black letters on brown background do not work. Climatic parameters – should P also be in mm/year, as ETP?
Response 18: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the correction in figure 3
Comment 19: Line 172: for in situ measurements?
Response 19: We thank the Reviewer 3 for this valuable and useful comment; you can see the correction Line 171
Comment 20: Line 186: use formula, rather than figure for equation; add (1) as this is equation
Response 20: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the laundry correction 185
Comment 21: Lines 188-189: nitrate and salinity repeats
Response 21: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I canceled the repetitions Line 187-189
Comment 22: Table 1 is result, it should not be in Materials and Methods!
Response 22: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the correction on line 256
Comment 23: Table 1: Round up to a same number of decimal places accordingly, e.g. why is Na+ in two, but Ca2+ with one decimal place? In my opinion, this table should be in supplementary material; if a table spans through several pages, every page should have table title and heading
Response 23: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the correction in table 1
Comment 24: Figure 4: What is locality in this figure? Also, networek – network
Response 24: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the correction in figure 4
Comment 25: Section 5.2.: this section is unnecessary in my opinion, these are the basic methods that are commonly used for representations of hydrochemical types. However, if you decide to leave this part, here are my comments: Piper’s diagram is not used in modelling; it hasn’t been recently used, it is commonly used; if you say that it is used in many studies, please add those studies (not just two); which software was used for Piper? Lines 200-207 is too long for 1 sentence!
Response 25: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the correction Line 194 and 196-201
Comment 26: Lines 214-215 and further: PCA is Principal Component Analysis
Response 26: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I have corrected the meaning of the CPA you can see line 209
Comment 27: Lines 219-220: Please check sentence, I don’t understand
Response 27: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the laundry correction 214-218
Comment 28: Line 249: The sentence starts with small letter
Response 28: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I put the letter in capital letters
Comment 29: Table 2: Line numbers overlap with the table; change decimal places, 3 are certainly not needed
Response 29: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see table 3
Comment 30: Lines 288-293: check commas, capital letters
Response 30: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I corrected to see the correction Line 274-279
Comment 31: Lines 326-331: If Line 186 is equation (1), then move these equations from 2-7
Response 31: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I corrected the numbering of equations see lines 311-316
Comment 32: Figure 8: increase the font where possible; use decimal point, not comma; what are the meaning of red arrows in Figure 8c)?
Response 32: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see figure 9. The meaning of the red arrows in figure 9c indicates that the ion Base Exchange reaction is reversible.
Comment 33: Line 342-243: … many quantity of organic fertilizers to double their yields… please rephrase. Maybe like: …overuse organic fertilizers to increase their yields…?
Response 33: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can go to line 327
Comment 34: Line 350: nitrite is NO2-!
Response 34: We thank the Reviewer 3 for this valuable and useful comment; I corrected NO2- see line 334
Comment 35: Lines 374-375 and 403: use decimal points
Response 35: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I used the decimals
Comment 36: Lines 376-383: too long sentence, meaning is lost
Response 36: We thank the Reviewer 3 for this valuable and useful comment; you can see the correction Lines 367-375
Comment 37: Lines 411-412: repeating
Response 37: We thank the Reviewer 3 for this valuable and useful comment; I cancelled the rehearsal
Comment 38: Lines 415-420: too long sentence
Response 38: We thank the Reviewer 3 for this valuable and useful comment I accept your comment, you can see the correction Lines 400-401 and 403-410;
Comment 39: Figure 10a): parameter names overlap the Dendrogram
Response 39: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I corrected you can see figure 11a
Comment 40: Line 447: None of the samples are at RMWL, all of them are below the line
Response 40: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment I arranged the sentence lines 418-419
Comment 41: Line 450 and further: Global Meteoric Water Line abbreviation is GMWL
Response 41: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I corrected abbreviation GMWL Line 421
Comment 42: Line 455: use 2 decimal places for d-excess
Response 42: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I used 2 decimals for d-excess Line 427
Comment 43: Lines 462-463: round δ18O to two, and δ2H to one decimal place; use VSMOW2
Response 43: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I rounded δ18O to two and δ2H to one decimal place and I used VSMOW2 see line 434-436
Comment 44: Line 480: d-excess repeating
Response 44: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I cancelled the rehearsals
Comment 45: Line 483: Use superscripts, check sentence
Response 45: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, you can see the correction Lines 454-458
Comment 46: Line 491: point, comma, capital letter – modify
Response 46: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment I have changed the sentence punctuation
Comment 47: Lines 491-495: check sentence, seems like random text
Response 47: We thank the Reviewer 3 for this valuable and useful comment; you can see the correction Lines 462-469
Comment 48: Table 5: Line numbers overlap with the table; change decimal places δ18O to two, d-excess to two, and δ2H to one decimal place
Response 48: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I have changed table 5
Comment 49: Conclusion is poorly written, seems like random text:
Lines 523-524: its-its-its repeating
Line 525-529: verb missing; what is the free layer? Too long sentence
Line 530: Statistical methods do not control chemistry, they can indicate something etc.
Line 530-536: too long sentence, meaning is lost
Response 49: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I rewrite the conclusion you can see the laundry correction 491-507
Comment 50: Line 551-552: revise-d; manuscript
Response 50: We thank the Reviewer 3 for this valuable and useful comment; I accept your comment, I have corrected
Comment 51: Author Contributions and Conflicts of Interest: The last sentence is repeating.
Response 51: We thank the Reviewer 3 for this valuable and useful comment, I accept your comment, I cancelled the rehearsals;
Reviewer 2 Report
The quality of groundwater used for agricultural purposes in the maknassy plain was assed using a combined chemical, isotopic and statistical approach. In addition to its important relevance for an effective water resources management in this agro-based local area in Tunisia, the research i could be useful for other similar semi-arid areas after including the following Comments:
1. The locations of your sampling wells (points) are not distributed evenly, What is the interpolation methods used for the construction of the spatial distribution maps of salinity (Fig. 5), Nitrate (Fig.9). It is very important to test the variogram model (Please refer to Sherif et al., 2021).
2. Why the very important relation between electrical conductivity and total dissolved solids was plotted as has been done for other parameters in Figure 6.
3. Please explain the source of high salinity (more than 10,000 mg/l) in the north-eastern part of the study area.
4. Please explain the source of high Nitrate (more than 50 mg/l) in the north-eastern part of the study area
Author Response
Responses to the comments of Reviewer #1
Comment 1: The locations of your sampling wells (points) are not distributed evenly, what is the interpolation methods used for the construction of the spatial distribution maps of salinity (Fig. 5), Nitrate (Fig.9). It is very important to test the variogram model (Please refer to Sherif et al., 2021).
Response 1: Thank you very much for your detailed and useful comments. We have addressed each of them as follows. I accept your comment; the interpolation method I used is the universal kriging method by the Arcgis software. I add the variogram model (Figure 6) Line 266.
Comment 2: Why the very important relation between electrical conductivity and total dissolved solids was plotted as has been done for other parameters in Figure 6.
Response 2: Thank you very much for your useful comments. We have addressed each of them as follows. I accept your comment, the relationship is very important between electrical conductivity and total dissolved solids because the electrical conductivity is in fact a measure of the ionic activity of a solution in terms of its ability to transmit current thus in a diluted solution, dissolved solids and the electrical conductivity are fairly comparable. Dissolved solids of a water sample, based on the calculated value of electrical conductivity.
Comment 3: Please explain the source of high salinity (more than 10,000 mg/l) in the north-eastern part of the study area.
Response 3: We thank the Reviewer 1, this useful comment. We have addressed each of them as follows. I accept your comment; the correction is in line 237-244
Comment 4: Please explain the source of high Nitrate (more than 50 mg/l) in the north-eastern part of the study area
Response 4: We thank the Reviewer 1 for this valuable and useful comment. We have addressed each of them as follows.I accept your comment; the correction is in line 239-346
Reviewer 3 Report
I’ve found interesting the manuscript Hydrology 2022, 9, x. https://doi.org/10.3390/xxxxx submitted by Zouhour Moussaoui, Matteo Gentilucci, Khyria Wederni,Naima Hidouri,Monji Hamdi, Zahra Dhaoui and Younes Hamed. I hope it will be soon published after some minor possible updates. In particular Authors studied Central Tunisia's Maknassy plain which is one of the country's most important agricultural basins. Due to the semiarid climate, the irrigation of cultivated crops is mostly dependent on the extraction of groundwater resources. Three categories of groundwater quality are represented by the examined waters, namely calcium chloride, calcium sulphate, and magnesium sulphate. A multivariate statistical analysis (PCA and AHP) and a geochemical technique were used to analyse water quality as a function of chemical factors. The stable isotopic compositions of the tested fluids range from -7.5294 to -4.8968 vs SMOW for 18O and 2H, (better to utilize two decimals only like -7.53 and 4.90) demonstrating the exchange between groundwater and rock and the evaporation effect. Isotopic analyses establishing three distinct groups of recent rain infiltration, paleo-recharge, and mixing influence suggest that dissolution and other processes affect the geochemical composition of rainwater during penetration. Therefore, these aquifers were refilled by precipitation coming from a blend of Atlantic and Mediterranean steam masses. Are Authors able to exclude the utilization by agriculture of fertilizers or ammendants like Nitrophoska or Magnesium Sulphate or Ammonium Nitrate?I think some comments would be appreciated by Readers.The addition of Tritium and 14C data (also coming from previous literature) would strongly support findings about palaeowaters and about Deuterium excess (see also, as an example, Martinelli et al. 2014. Isotopic features of Emilia-Romagna region (North Italy) groundwaters: environmental and climatological implications. J. Hydrol. 519 (Part B), 1928–1938.)
(Yundi Hu, Zaihua Liu, Min Zhao, Qingrui Zeng, Cheng Zeng, Bo Chen, Chongying Chen, Haibo He, Xianli Cai, Yi Ou, Jia Chen (2018) Using deuterium excess, precipitation and runoff data to determine evaporation and transpiration: A case study from the Shawan Test Site, Puding, Guizhou, China,
Geochimica et Cosmochimica Acta,Volume 242, 21-33)
(Jie Li, Zhonghe Pang, Klaus Froehlich, Tianming Huang, Yanlong Kong, Wenhui Song, Hongxiang Yun (2015) Paleo-environment from isotopes and hydrochemistry of groundwater in East Junggar Basin, Northwest China, Journal of Hydrology,Volume 529, Part 2, 650-661)
Author Response
Responses to the comments of Reviewer #2
Comment 1: I’ve found interesting the manuscript Hydrology 2022, 9, x. https://doi.org/10.3390/xxxxx submitted by Zouhour Moussaoui, Matteo Gentilucci, Khyria Wederni,Naima Hidouri,Monji Hamdi, Zahra Dhaoui and Younes Hamed. I hope it will be soon published after some minor possible updates. In particular Authors studied Central Tunisia's Maknassy plain which is one of the country's most important agricultural basins. Due to the semiarid climate, the irrigation of cultivated crops is mostly dependent on the extraction of groundwater resources. Three categories of groundwater quality are represented by the examined waters, namely calcium chloride, calcium sulphate, and magnesium sulphate. A multivariate statistical analysis (PCA and AHP) and a geochemical technique were used to analyse water quality as a function of chemical factors. The stable isotopic compositions of the tested fluids range from -7.5294 to -4.8968 vs SMOW for 18O and 2H, (better to utilize two decimals only like -7.53 and 4.90) demonstrating the exchange between groundwater and rock and the evaporation effect. Isotopic analyses establishing three distinct groups of recent rain infiltration, paleo-recharge, and mixing influence suggest that dissolution and other processes affect the geochemical composition of rainwater during penetration. Therefore, these aquifers were refilled by precipitation coming from a blend of Atlantic and Mediterranean steam masses. Are Authors able to exclude the utilization by agriculture of fertilizers or ammendants like Nitrophoska or Magnesium Sulphate or Ammonium Nitrate?I think some comments would be appreciated by Readers.The addition of Tritium and 14C data (also coming from previous literature) would strongly support findings about palaeowaters and about Deuterium excess (see also, as an example, Martinelli et al. 2014. Isotopic features of Emilia-Romagna region (North Italy) groundwaters: environmental and climatological implications. J. Hydrol. 519 (Part B), 1928–1938
Response 1: We thank the Reviewer 2 for this valuable suggestion and we agree.
I take your point that in the study area there is no isotopic groundwater work. This is the first isotope study in the Maknessy Basin. It will be carried out in future studies on tritium and 14C
Round 2
Reviewer 1 Report
Manuscript ID: hydrology-2153620
Title: Hydrogeochemical and stable isotope data of groundwater of a multi-aquifer system of Maknessy basin (Mediterranean area, central Tunisia)
by Zouhour Moussaoui, Matteo Gentilucci, Khyria Wederni, Naima Hidouri, Monji Hamdi, Zahra Dhaoui and Younes Hamed
Written evaluation – Round 2 comments
1) language editing required
The text is now better, but surely needs proofreading, I suggest MDPI language editing service.
2) As I understand HCA and PCA analyses were done. Why the abstract says AHP? Why the conclusion states CAC?
3) Line 28 – remove „quality“, these are not groundwater quality types
4) Line 80: Please rephrase to not start the sentence with brackets.
5) There is no reference on Figure 2 within text. – to be clear, you do not mention Figure 2 in the text. Maybe add (Figure 2) after first sentence (line 111)
6) Figure 3: Is the altitude in (m a.s.l.) and not in (m)? What is biological agricultural?
7) Figure 4: It still says hydrographic networek.
8) Lines 434-435: remove „vs SMOW“
9) Line 492: remove „ ,which “
10) Line 496-498: verb missing (were able to determine?)
11) Line 498: Maybe it would be clearer if you write: Two categories of groundwater were observed, namely...
12) Author Contributions and Conflicts of Interest: The last sentence is still repeating. – remove one
Author Response
Responses to the comments of Reviewer 3
Comment 1: Language editing required
The text is now better, but surely needs proofreading; I suggest MDPI language editing service.
Response 1: Thank you very much for your detailed and useful comments. We have addressed each of them as follows. Thank you for viewer’s suggestion. The text has been revised.
Comment 2: As I understand HCA and PCA analyses were done. Why the abstract says AHP? Why the conclusion states CAC?
Response 2: Thank you very much for your useful comments. We have addressed each of them as follows. I accepted your comment, it’s a typo, and I corrected it. You can see the correction Line 29 and 499.
Comment 3: Line 28 – remove „quality“, these are not groundwater quality types
Response 3: Thank you very much for your useful comments. We have addressed each of them as follows.I accepted your comment, I removed it, and you can see the correction Line 28
Comment 4: Line 80: Please rephrase to not start the sentence with brackets.
Response 4: Thank you very much for your useful comments. We have addressed each of them as follows. I accepted your comment; you can see the correction Line 80 and 81.
Comment 5: There is no reference on Figure 2 within text – to be clear, you do not mention Figure 2 in the text. Maybe add (Figure 2) after first sentence (line 111)
Response 5: Thank you very much for your useful comments. We have addressed each of them as follows. I accepted your comment, I added it you can see the correction Line 111
Comment 6: Figure 3: Is the altitude in (m a.s.l.) and not in (m)? What is biological agricultural?
Response 6: Thank you very much for your useful comments. We have addressed each of them as follows.I accepted your comment; you can see the correction in figure 3.
Biological agricultural is a mode of agricultural production that excludes the use of synthetic substances, such as pesticides and chemical fertilizers. It is defined by the use of fertilizers of organic origin, such as manure, compost, natural fertilizer or bone meal.
Comment 7: Figure 4: It still says hydrographic networek.
Response 7: Thank you very much for your useful comments. We have addressed each of them as follows.I accepted your comment; you can see the correction in figure 4
Comment 8: Lines 434-435: remove „vs SMOW“
Response 8: Thank you very much for your useful comments. We have addressed each of them as follows.I accepted your comment; I removed it, and you can see the correction Line 434
Comment 9: Line 492: remove „ ,which “
Response 9: Thank you very much for your useful comments. We have addressed each of them as follows.I accepted your comment; I removed it, and you can see the correction Line 492.
Comment 10: Line 496-498: verb missing (were able to determine?)
Response 10: Thank you very much for your useful comments. We have addressed each of them as follows.I accepted your comment; you can see the correction Line 495-496
Comment 11: Line 498: Maybe it would be clearer if you write: Two categories of groundwater were observed, namely...
Response 11: Thank you very much for your useful comments. We have addressed each of them as follows.I accepted your comment; you can see the correction Line 496-497
Comment 12: Author Contributions and Conflicts of Interest: The last sentence is still repeating. – remove one
Response 12: Thank you very much for your useful comments. We have addressed each of them as follows.I accepted your comment; I removed it in Conflicts of Interest, and you can see the correction Line 531
Best regards
All authors
