The Effects of Regional Fluid Flow on Deep Temperatures (Hesse, Germany)

Round 1

Reviewer 1 Report

The paper address the effects of fluid flow on the geothermal potential of The Federal state of Hesse is located in central Germany. They have identified areas where the deep thermal field is controlled by conductive heat transport, and by convection heat transport. This is a very interesting topic and can be extended to other regions across the world.

The manuscript presented material in a very logistical manner, with clear description about the structure, temperature and hydraulic data used. The model is also validated with the measured thermal, hydraulic and geochemical data.

However, there are many English usage errors throughout - please review with a technical writer, For example: 

On Page 1 Lines 43-45  In particular, we address the following question; which contribution different heat transport mechanisms have in defining the deep thermal field of Hesse.

On Page 5: Lines 147-148: All previous physical models [8, 19-21, 23, 32] were built on the base of the same structural model  of Hesse of Arndt [20], introduced in chapter 3.1. I think here authors are referring to section 2.1, there are no chapters in a journal article

On Page 7 Lines 204-205: According to this, six  geological layers are represented by 21 numerical layers (Table 1). I think here authors are referring to table 2 not table 1.

On page 25 Lines 732-734: This said, we could be positive in this work while stating that our regional anal<sis has been able to pin point specific areas where free convective heat transport is expected to occur, thus providing a physics based guidelines for additional an future activities.

On Page 28 Line 845: B.2. Racharge data Supplementary Material is missing in the submission.

Some of the details in section 2 and 3 can be included in appendix to increase attention to the actual results of the paper.

Discussion section is too lengthy.

Though the paper addresses a very interesting topic, it cannot be accepted without a more thorough edit to improve awkward phrasing and increase readability of the manuscript.

Author Response

Response to Reviewer 1 Comments

Point 1: On Page 1 Lines 43-45  In particular, we address the following question; which contribution different heat transport mechanisms have in defining the deep thermal field of Hesse.

Response 1: The sentence was edited: In particular, we address the following question: Which contribution have different heat transport mechanisms in defining the deep thermal field of Hesse?

Point 2: On Page 5: Lines 147-148: All previous physical models [8, 19-21, 23, 32] were built on the base of the same structural model of Hesse of Arndt [20], introduced in chapter 3.1. I think here authors are referring to section 2.1, there are no chapters in a journal article

Response 2: Thank you for the advice. We changed the link to section 2.1. All other “chapters” were changed to “sections”.

Point 3 On Page 7 Lines 204-205: According to this, six  geological layers are represented by 21 numerical layers (Table 1). I think here authors are referring to table 2 not table 1.

Response 3: The link was changed to Table 2.

Point 4: On page 25 Lines 732-734: This said, we could be positive in this work while stating that our regional anal<sis has been able to pin point specific areas where free convective heat transport is expected to occur, thus providing a physics based guidelines for additional an future activities.

Response 4: anal<sis was changed to analysis.

Point 5 On Page 28 Line 845: B.2. Racharge data Supplementary Material is missing in the submission.

Response 5: That is true. Both data sets are already published and therefore cannot be published again (but can be looked up: Kopp, B., Baumeister, C., Gudera, T., Hergesell, M., Kampf, J., Morhard, A., Neumann, J., Entwicklung von Bodenwasserhaushalt und Grundwasserneubildung in Baden-Württemberg, Bayern, Rheinland-Pfalz und Hessen von 1951 bis 2015. Hydrologie & Wasserbewirtschaftung 2018, 62, 62-76 And BGR, Hydrologischer Atlas von Deutschland, Tafel 5.5 - Mittlere jährliche Grundwasserneubildung. In 2003). The maps show the data with all needed information for the discussion.

Point 6 Some of the details in section 2 and 3 can be included in appendix to increase attention to the actual results of the paper.

Response 6: The details of the properties in section 3.3 were shifted to Appendix C and all reference numbers were adjusted accordingly.

“More details on lithology of the resolved units can be looked up in Appendix C.”

Point 7 Discussion section is too lengthy.

Response 7: As we think that in the discussion only relevant and important points are described and Point 7 is very vague we did not change this section.

Author Response File: Author Response.docx

Reviewer 2 Report

Paper is very interesting and has been very carefully prepared. The authors' significant contribution is visible - results of numerical simulation, the figures are well prepared, their selection is appropriate, the figures show both the geological background and the obtained simulation results. My minor remarks concern details: I just wonder if there is mistake in the scale description on figure B2-b - value of 687- is it not linear scale? Figure 14- scale - km asl?

Author Response

Response to Reviewer 2 Comments

Point 1: My minor remarks concern details: I just wonder if there is mistake in the scale description on figure B2-b - value of 687- is it not linear scale?

Response 1: Yes that is true. The scale is not linear. This is based on the set of data we used and the best way to visualize the recharge differences. When we checked the data again, we found a problem with the maximum recharge rate, therefore it was changed accordingly.

Point 2: Figure 14- scale - km asl?

Response 2: Yes, thank you. The scale of the depth of the basement is indeed km above sea level. We changed the Figure accordingly.

The Figures are implemented in the submitted word file.

Author Response File: Author Response.docx