Review Reports - Groundwater Prospecting Using a Multi-Technique Framework in the Lower Casas Grandes Basin, Chihuahua, México

Round 1

Reviewer 1 Report (New Reviewer)

The positive aspects of the work are: showing a multilateral analysis of aquifer in desert areas and examples of the use of various tools for its assessment. Examples illustrating the legitimacy of using various methods in practice and drawing attention to the economics of searching for aquifers in areas with a complex geological structure have an undeniable scientific value. Too "flowery" descriptions of the importance of groundwater for the economy require improvement and shortening. Too detailed, according to the reviewer, “flowery” descriptions regarding local interpretations of the results of water-bearing tests of individual regions should also be removed, because the foreign reader does not know the exact geological structure of the described areas. After making abbreviations and corrections, the work will meet the requirements for its publication.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report (New Reviewer)

(1) 2. Materials and Methods and 3. Results: Appropriate compression is recommended.

(2)Figure 5. Regional geologic settings at the Ascension aquifer (0801)：Geologic map legends should be arranged from new to old by geologic time.

(3)Figure 5. Electrical conductivity and resistivity values for different rocks. Should be Figure 6. Modify the numbers of subsequent figures and the numbers referenced in the text.

(4)Table 2: The Accum. of eigenvalues in PCA Layer 4 to PCA Layer7 are incorrect. Please check.

(5) Figure 10. The best fit curve (a) and layered model (b) for Vertical Electrical Sounding (VES) at site 2: The necessary legend is missing.

(6)Figure 11. Vertical Electrical Sounding (VES) at site 1 best fit curve and layer models: The necessary legend is missing.

(7) Figure 17. Updated SWL for 2022 for the regional Ascension aquifer (0801)：It is proposed to add equipotential lines and groundwater flow direction in 1998 to the figure.

(8）References：Description format is confusing.

Author Response

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Reviewer 3 Report (New Reviewer)

1. Abstract should be more sound and highlight the important key findings Refer: https://doi.org/10.1080/10106049.2022.2158951; https://doi.org/10.1016/j.asoc.2022.109739

2. Why did you use this "Schlumberger" method for your study region. add the details in methodology section

3.Add the details of instruments used for VES with model number

4. Discussion part need to modified. Highlight the important research finding and discuss in detail. refer:https://doi.org/10.3390/w14213549; https://doi.org/10.1016/j.measurement.2022.112230

5. Split the conclusion section into two. Add the recommendation of the present research objective and add conclusion Refer: https://doi.org/10.1016/j.egyr.2022.09.015

6. Check references as per journal format

Author Response

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Reviewer 4 Report (New Reviewer)

Granados-Olivas et al. presented a multi-technique framework to evaluate potential sites to drill for groundwater resources. The main components of the methodology include well-head leveling correction with a differential global positioning survey to define piezometric levels, principal component analysis using Landsat-8 images, application of geospatial tools, geophysics using time domain electromagnetic surveys (TDES) and vertical electric soundings (VES), and structural geo-hydrology to define aquifer characteristics. The work is well researched and well presented. I recommend the authors address following comments/suggestion prior to further consideration of the manuscript.

1- Improve the introduction by better pointing out the novelty of your work, and its importance for the literature.

2- The workflow in figure 4 should be clearer, consider revising.

3- Figure 7 can be deleted from the manuscript.

4- Figure 11 have a very low resolution quality, consider changing the figure.

5- The conclusion section is rather long. Please only provide the outcomes of the research and highlight its significance for future research.

Author Response

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Reviewer 5 Report (New Reviewer)

The paper presents a multi-technique framework to evaluate potential sites to drill for groundwater resources, in the Lower Casas Grandes Basin, México. It is a suitable topic for Water MDPI journal. The manuscript is professionally written, clear, and easy to read. The results are relevant, well presented and discussed.

I recommend a minor revision of the manuscript following my unique comment below:

The manuscript's novelty should be (more) explored in the Abstract, Introduction, and Conclusions.

Author Response

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Round 2

Reviewer 2 Report (New Reviewer)

Figure 17. The picture name and legend are confused, and the representation of the picture is wrong. The equipotential lines and groundwater flow direction in 1998 should be added to the original drawing (equipotential lines and groundwater flow direction in 2022).

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report (New Reviewer)

Author Response

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Author Response File: Author Response.docx

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

This paper explained how to use a multiple method to locate potential sites for drilling groundwater wells. The title of “aquifer characterization” was not achieved in methods nor in the results.

What is the type of aquifer (fracture hard rocks)? What is the thickness of the aquifer? How permeable is the aquifer (hydraulic conductivity values)? How much is the groundwater recharge? How much is the well yield? How much groundwater is abstracted and for what purposes? How many groundwater level monitoring wells and what are historical changes of groundwater levels? Who can afford to pump groundwater at a depth of 240m?

If the authors can address above the questions, the revised manuscript may be considered for publication.

Author Response

Water Journal

Manuscript ID 2100255

Response to Reviewer 2 Comments

Comments and Suggestions for Authors

In the paper entitled ‘Hydrogeological aquifer characterization using a multi-technique framework: Application to the Lower Casas Grandes Basin, Chihuahua, Mexico’ the authors explored the groundwater potential of the area applying multi-technique framework (remotely sensed reconnaissance and geophysical prospecting). A survey was carried out to update the static water level in the region. The article is interesting and is in the scope of Water journal. However, the article needs some improvements before its consideration for publication.

Response: Thank you for your comments and suggestions. I appreciate your time and effort while reviewing our paper. I have integrated and improved the paper which includes all your recommendations and incorporates text which aims into all your comments. Again, thank you for your time and observations.

Language used throughout the entire of length of article must be improved, especially the sentence structure. Also enrich the text with technical terminology of the subject.

Response: I have worked throughout the updated version of our paper to improve the sentence structure, add more technical terminology, and expand the sections for more clarity and understanding. Also, the document was edited by the MPDI English Editing system. Thank you.

Title: Tile is very long please, reduce its length.

Response: I have changed the title of our paper. Hope this complies with your request. Thank you.

Introduction: The overall scope of the entire article especially the introduction is very narrow. I recommend the authors to include citations of other studies from different parts of the globe for groundwater exploration in alluvial aquifers using similar techniques. Please, shuffle the paragraphs 2 and 3. Line 79-80 a reference is required. Line 70 set abbreviations for principal component analysis (PCA) then use it for the entire length of the article.

Response: I have expanded the overall scope of the introduction section adding more details and citations on the specifics of the aquifer and other additional information in regard to its hydrogeological characteristics. Paragraphs 2 and 3 were rearranged and expanded on their rationale. A specific reference was added in regard to the sentence on lines 79-80. All acronyms throughout the document were fixed and used as suggested. Thank you.

Methods: Describe what is PCA?. Any specific reason for choosing VES with Schlumberger electrode configuration?

Response: I have added a description of what is PCA in the application of remote sensing. Regarding the Schlumberger configuration for the VES´s is because the Schlumberger method is very useful when it is necessary to know the resistivities of deeper layers, without the need to carry out many measurements as with the Wenner method. I have added a more detailed explanation of this section to our updated version of the paper. Thank you.

Study area. Lines 105-120 should move to introduction.

Response: Agree. I have completely restructured the introduction section on the new version of our paper which includes this specific section as you suggest. Thank you.

Results: Show the values of RMS for all resistivity models.

Response: In the updated version of our paper, values for RMS were added for the presented resistivity models. Also, additional wording was integrated into the text for a more clear and more comprehensive explanation. Thank you.

Conclusions: The first paragraph (line 530 to 539) of conclusion should be moved and merged with the last paragraph of introduction.

Response: Agree. In the updated version of our paper, I have moved some paragraphs of this section and adjusted the rationale in the introduction section. Thank you.

viii)Figures Quality of all figures need improvement. Legends of figures need more details so that reader can get an idea of the figures without reading the text.

Response: I have updated and reworked all figures to improve their quality and clearness for readers to understand and catch the main ideas that we suggest on the paper, including re-editing all legends on the figures with specific explanations on the displayed images. Thank you.

Figure 1 Location map is very poor and too narrow it should also cover regional context. Legend also requires little more details. Instead of taking it from others work I recommend the authors to plot it by themselves.

Response: Agree. I have re-edited all maps according to international cartographic standards plotting our own maps using GIS and official data sets from the Mexican cartography agency. Thank you.

Figure 2 is very poor and make no sense. Please, plot it differently. Change ‘roadmap’ to workflow.

Response: The main idea in this figure was to have a set of sequential steps to address the issue of groundwater prospecting. I have plotted differently on the updated paper. Also, I have changed the word as suggested. Thank you.

Figure 10 impossible to read, please improve its quality.

Response: Agree. I have re-edited this figure and enhanced the legend text for clarity. Thank you.

Merge figures 12 and 13. It would be interesting to see the change in Equipotential lines.

Response: I have reworked both figures projecting them under international cartographic standards and kept both on the document for reference and support to the integrated descriptive text. Change of SWL is shown in tabular form within the figure showing the updated information for 2022. Thank you.

xiii)Line 318-320 Please show the results from video camera used ? “The hydrostratigraphic units at both sites was further investigated with a downhole video ca- 319 mara recording in the previously drilled well (Pozo El Menón) till a depth of 150 m ”

Response: This text was eliminated from the updated version of our paper. Thank you.

xiv)Table 1 is not necessary, you may remove it.

Response: Agree. In the updated version of our paper, I have eliminated this table from the main body of the text and reordered all other tables. Thank you.

Minor erros:

Line 164 add a reference of the USGS site from where the LANDSAT 8 data were obtained.

Response: Done. Thank you.

Line 171 add a space between number and units (30 m).

Response: Done. Thank you.

Line 192 change [13] [14] to [13,14].

Response: Done. Thank you.

Change heading 2.5 to ‘Geophysical surveys’.

Response: Done. Thank you.

Line 485 direction of groundwater

Response: Not sure which sentence or figure you are addressing; however, all figures and their related explanations in regard to groundwater flow direction were explained and referenced in the updated version of our paper. Thank you.

Author Response File: Author Response.docx

Reviewer 2 Report

Language used throughout the entire of length of article must be improved, especially the sentence structure. Also enrich the text with technical terminology of the subject.
Title: Tile is very long please, reduce its length.
Introduction: The overall scope of the entire article especially the introduction is very narrow. I recommend the authors to include citations of other studies from different parts of the globe for groundwater exploration in alluvial aquifers using similar techniques. Please, shuffle the paragraphs 2 and 3. Line 79-80 a reference is required. Line 70 set abbreviations for principal component analysis (PCA) then use it for the entire length of the article.
Methods: Describe what is PCA?. Any specific reason for choosing VES with Schlumberger electrode configuration?
Study area. Lines 105-120 should move to introduction.
Results: Show the values of RMS for all resistivity models.
Conclusions: The first paragraph (line 530 to 539) of conclusion should be moved and merged with the last paragraph of introduction.
viii)Figures Quality of all figures need improvement. Legends of figures need more details so that reader can get an idea of the figures without reading the text.
Figure 1 Location map is very poor and too narrow it should also cover regional context. Legend also requires little more details. Instead of taking it from others work I recommend the authors to plot it by themselves.
Figure 2 is very poor and make no sense. Please, plot it differently. Change ‘roadmap’ to workflow.
Figure 10 impossible to read, please improve its quality.
Merge figures 12 and 13. It would be interesting to see the change in Equipotential lines.
xiii)Line 318-320 Please show the results from video camera used ? “The hydrostratigraphic units at both sites was further investigated with a downhole video ca- 319 mara recording in the previously drilled well (Pozo El Menón) till a depth of 150 m ”
xiv)Table 1 is not necessary, you may remove it.

Minor erros:

Line 164 add a reference of the USGS site from where the LANDSAT 8 data were obtained.

Line 171 add a space between number and units (30 m).

Line 192 change [13] [14] to [13,14].

Change heading 2.5 to ‘Geophysical surveys’.

Line 485 direction of groundwater

Author Response

Water Journal

Manuscript ID 2100255

Response to Reviewer 1 Comments

Thank you for your comments and suggestions. I appreciate your time and effort while reviewing our paper. I have integrated an improved paper that includes all your recommendations and integrates text along the document which focuses on more detail in all your comments. Again, thank you for your questions.

This paper explained how to use a multiple method to locate potential sites for drilling groundwater wells. The title of “aquifer characterization” was not achieved in methods nor in the results.

Response: We have included additional graphics with schematics on the characterization of the structural geology in the areas of interest. We also added text explaining the regional geology and expanded the interpretation of the geophysics results which helped with this characterization. Thank you.

What is the type of aquifer (fracture hard rocks)?

Response: Based on official publications from the Mexican water authority (CONAGUA), the Ascension Valley originated from tectonic rifts filled by deposits of alluvial materials of very heterogeneous granulometry. It is considered an unconfined aquifer unit with medium to high permeability characteristics. However, the main objective of this research was to locate potential faults in the fracture hard rocks on the mountain front that could have potential recharge from a higher elevation from the headwaters. I have added text on the paper expanding in regards to the type of aquifer at the study site. Thank you.

What is the thickness of the aquifer?

Response: Average aquifer thickness at the Mexican section of the Basin and Range Province where the Lower Casas Grandes Basin is located varies from 300 m up to 2000 m in depth. This information was added to the updated version of our paper. Thank you.

How permeable is the aquifer (hydraulic conductivity values)?

Response: The hydraulic characteristics of the aquifer were considered contemplating the transmissivities obtained from pumping tests carried out in the aquifer of Janos, which is next to Ascension which was done by CONAGUA. Transmissivities in the Janos zone according to a study carried out in 1972 by CONAGUA, ranged from 1 to 50 x 10-3 m2/s with an average value of 4 x 10-3 m2/s; and according to the updated 1979 study, the transmissivities are less than 5 x10-3 m2/s. In the area of the Ascensión aquifer, which presents characteristics similar in its geology to that of Janos, it is estimated that the average value of transmissivity is 4 x 10-3 m2/s. The value of the storage coefficient is estimated to be of the order of 0.03. I have added this explanation to the updated version of our paper. Thank you.

How much is the groundwater recharge?

Response: The recharge of the aquifer comes from the area where the Casas Grandes River and the Salto del Ojo stream are located; locally recharges occur from rainwater that precipitates and infiltrates the mountain front at El Capulín (study site). Also, recharge is present through the El Fresnal mountain range located in the eastern part of the eastern mountains. The lower parts of the valley also allow recharge to the aquifer through rainwater infiltration and irrigation water returns. According to CONAGUA the natural recharge is considered as the sum of the infiltration of rainwater plus the subterranean flow coming from the mountainous areas that surround the valley and from the entering through the southwestern part from Janos, it has been calculated at 94.2 Mm3/year. For rainwater, a valley area of 2000 km2 was considered, with precipitation of 289.4 mm and an infiltration coefficient of 0.08 which gives results in a natural recharge of 48.6 Mm3/year. Horizontal recharge by lateral flow is 45.6 hm3/year. The induced recharge comes from groundwater used for irrigation and a lower proportion of water used for domestic uses and urban public uses. The total amount of induced recharge has been calculated at 38.0 hm3/year, which is calculated by multiplying the volume applied to irrigation (187 Mm3/year of groundwater) by an infiltration coefficient of 0.20 and multiplying the volume used in domestic and public urban uses (3.04 Mm3/year) for a coefficient of 0.20. This information was added to the updated version of our paper. Thank you.

How much is the well yield?

Response: Average range of well yields at the study site varies from 10 to 150 l/s where most of the well infrastructure is designed to pump an average of 64 l/s. This information was added to the updated version of our paper. Thank you.

How much groundwater is abstracted and for what purposes?

Response: The total extraction of groundwater in the area is about 241.2 hm3/year (Feb 20, 2020), which is destined mainly for agriculture and to a much lesser extent for domestic, urban, and industrial uses. This information was included in the updated version of our paper. Thank you.

How many groundwater level monitoring wells and what are historical changes in groundwater levels?

Response: For our paper, we only monitored 5 wells for the 2022 update on SWL which showed an average drawdown of 7 m/year as compared to the latest SWL survey done by CONAGUA in 1998. However, in México it is required by law that at least 10% of the well infrastructure should be monitored to update groundwater evolution. That is, out of the 632 existing wells in the watershed (2020) at least 63 wells were used as monitoring wells. The Ascensión aquifer has systematic groundwater evolution data from 1977 until the year 1998. According to the data on the evolution of the static water level from 1987-1998, the aquifer presents an average drawdown of –1.0 m/year. However, in the vicinity of the town of Ascensión, there are maximum drawdowns of -29.0 m ( -2.4 m/year); The drops in groundwater levels in this area range from –5.0 to -29.0 m (-0.4 to -2.4 m/year) occur as an elongated cone in the direction south to north, that is to say in an ellipsoidal shape, and with a length of the order of 25 km on its longest axis and 15 km on its short axis. These drops in static water levels are due to the large extraction of groundwater and the concentration of pumping wells. This information was included in the updated version of our paper. Thank you.

Who can afford to pump groundwater at a depth of 240m?

Response: Since there is an urgent need for groundwater in the study area, many ranchers are struggling for water to provide to their cattle. Hence, they are willing to risk high investments to solve their water problems. Furthermore, ever since there is new pumping technology available, many of these ranchers are installing solar panel infrastructure to pump groundwater at greater depths. Moreover, low-yielding wells (1 or 2 l/s) could be a significant difference and a lifesaving infrastructure for these families when they can have it on their rangeland. I have added a text on our updated paper justifying this issue. Thank you.

Water Journal

Manuscript ID 2100255

Response to Reviewer 2 Comments

Comments and Suggestions for Authors

Response: Thank you for your comments and suggestions. I appreciate your time and effort while reviewing our paper. I have integrated an improved the paper which includes all your recommendations and incorporates text which aims into all your comments. Again, thank you for your time and observations.

Language used throughout the entire of length of article must be improved, especially the sentence structure. Also enrich the text with technical terminology of the subject.

Response: I have worked throughout the updated version of our paper to improve the sentence structure, add more technical terminology, and expand the sections for more clarity and understanding. Also, the paper was edited by the MPDI English Editing system. Thank you.

Title: Tile is very long please, reduce its length.

Response: I have changed the title of our paper. Hope this complies with your request. Thank you.

Methods: Describe what is PCA?. Any specific reason for choosing VES with Schlumberger electrode configuration?

Response: I have added a description of what is PCA in the application of remote sensing. Regarding the Schlumberger configuration for the VES´s is because the Schlumberger method is very useful when it is necessary to know the resistivities of deeper layers, without the need to carry out many measurements as with the Wenner method. I have added a more detailed explanation in this section of our updated version of the paper. Thank you.

Study area. Lines 105-120 should move to introduction.

Response: Agree. I have completely restructured the introduction section on the new version of our paper which includes this specific section as you suggest. Thank you.

Results: Show the values of RMS for all resistivity models.

Conclusions: The first paragraph (line 530 to 539) of conclusion should be moved and merged with the last paragraph of introduction.

Response: Agree. In the updated version of our paper, I have moved some paragraphs of this section and adjusted the rationale in the introduction section. Thank you.

viii)Figures Quality of all figures need improvement. Legends of figures need more details so that reader can get an idea of the figures without reading the text.

Response: Agree. I have re-edited all maps according to international cartographic standards plotting our own maps using GIS and official data sets from the Mexican cartography agency. Thank you.

Figure 2 is very poor and make no sense. Please, plot it differently. Change ‘roadmap’ to workflow.

Figure 10 impossible to read, please improve its quality.

Response: Agree. I have re-edited this figure and enhanced the legend text for clarity. Thank you.

Merge figures 12 and 13. It would be interesting to see the change in Equipotential lines.

Response: This text was eliminated from the updated version of our paper. Thank you.

xiv)Table 1 is not necessary, you may remove it.

Response: Agree. In the updated version of our paper, I have eliminated this table from the main body of the text and reordered all other tables. Thank you.

Minor erros:

Line 164 add a reference of the USGS site from where the LANDSAT 8 data were obtained.

Response: Done. Thank you.

Line 171 add a space between number and units (30 m).

Response: Done. Thank you.

Line 192 change [13] [14] to [13,14].

Response: Done. Thank you.

Change heading 2.5 to ‘Geophysical surveys’.

Response: Done. Thank you.

Line 485 direction of groundwater

Author Response File: Author Response.docx