Identification of Aquifer Systems in Weathered and Fractured Sandstone Based on 3D Geological Modeling in the Mesa de Los Santos (Santander, Colombia)

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript presents a 3D geological model of the Mesa de Los Santos, situated in Santander, Colombia, constructed from stratigraphic and hydrogeological data. It contains three different aquifer systems: one is a shallow aquifer (SAS), the upper aquifer 1 (UA1), and the upper aquifer 2 (UA2). The authors determine the groundwater flow through the different aquifers and fracture patterns, using hydrodynamic parameters. The manuscript is well-written and supported by a substantial bibliography.  To improve the manuscript, I recommend improving/integrating the following issues:

1. Highlights in the abstract, introduction, and conclusions, the obtained results, and how they improve the findings with respect to the previous bibliography. It is unclear what the new contribution of this study is in relation to the earlier findings.
2. For example, in section 4.1.3. The 3D model does not clearly indicate what is new in Figure 7 with respect to References [33,46] (lines 422-426). BTW, references [33] do not work. Please update with a working link.
3. Regarding the stratigraphic data mentioned in the abstract and introduction, I suggest including some stratigraphic sections for points C#.
4. Expand the 3.2 section lines 276-277 to include which input parameters were used to construct the physical model.
5. Expand lines 292-294 to detail which is the contrubution of the actual study in comparison with references [38,43,45-47].
6. Expand lines 295-306 and include more details on the 3D model of the Los Santos formation and the Python's Gempy library.
7. In lines 310-312 were mentioned a field visit during 2020 and 2021. and in lines 315-316 in 2023. Were the piezometric values taken several times? Expand and put values into a Table.
8. expand the lines 322-326 were the isopiestic lines were constructed.
9. Describe briefly the methods and codes used. For example, which program was used to get the piezometric map of Figure 10? how the piezometric contours were determined ? if a numerical code was used, needs to show the grid used. The results seems to be low quality. What about the errors? 
10. Improve the quality of Figures: 1b), 8, 9, 10. 
11. Use a table (with the numbers) beside Figure 9. Standardize the form for the decimals used throughout the manuscript.
12. Highlight the limitations of this study in the conclusions and suggest ways to improve them for future research.

 

Author Response

see file

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

the topic is interesting but paper needs some significant improvements. On the first there is no information on the extension of the area under study. It could supposed standing on the rules in some maps. On the second, except for Figure 10, there is no information about the groundwater flow and piezometric trends. Moreover,  they are referred to isotopes data, but they are related to another papers, and in this site it would be good to include the synthesis of data previously published, in the aim do discuss. In other words in my opinion is that this paper is a good trailer which asks to be better organized and supported by data, which in this case are not enough, or they are not presented adequately. To present Hydrodynamics of an area it is required to focus on some more details on it. 

Author Response

see file

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear author/s,

after careful reading of your manuscript I attach bellow my comments/questions to be replied to:

The manuscript deals with a hydrogeological identification and presentation of the aquifer system in the Mesa de Los Santros (Colombia) based on the combination of different approaches (UAE; isotopes, piezometric head wells/boreholes, in situ observations).

Although wide range of methods/approaches are considered and used to perform presented study I do have concern in the lack of exact domain boundary definition. Hereby I want to emphasize it is not clear how the domain boundary has been defined (orographic, topographic, other). Since the dominant GW flow pathways indicate divergence of the flow towards the west (NW and SW) I am wondering how the basin boundary has been selected/decided upon. Hereby I want to highlight even the aquifer system cross section highlight the continuity of aquifer/aquitard units (Fig. 11. b)). 

Conclusions content mostly presents the repetition of the previous work (references) either the Results section. I kindly ask authors to improve the Conclusions section with clear and non ambigue content clearly representing novel findings arose from the study conducted within the manuscript. 

 

 

Author Response

see file

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Thank you for the opportunity to review your manuscript on the Los Santos Formation aquifers.  In general, it is very well written and organized.  I have provided a few comments and suggested edits.  A few additional figures would be helpful.  In addition a paragraph in the Conclusions explaining the novelty of your work would be helpful, especially in regard to the geologic setting, methods used, and complex aquifer distribution.

Comments for author File: Comments.pdf

Author Response

see file

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors answered all my questions in detail and improved the work. I have no further questions.

Reviewer 3 Report

Comments and Suggestions for Authors

Grateful to the authors.