Change Analysis of Karst Landforms, Hydrogeological Conditions and Effects of Tunnel Excavation on Groundwater Environment in Three Topography Grades in China
Round 1
Reviewer 1 Report
This paper contain good data, methodology and interpratation but to improve the quality I will suggest a minor revision
1- Try to enrich the abstract with TDS values, isotopic composition...
2- More detail the tectonic setting and more explain the faults role in the interconnectivity of tunnels and in the hydrodynamic of groundwater
3- What about the flow rate of the springs (near/far the faults), is there any relationship (quantity and quality)?
4- More explain the isotopic variation vs altitude (See the ref of Hamed et al., 2008, 2010, 2014)
5- Is there any karst aquifer pollution by anthropogenic activities (industrial, agriculture, etc) in the study area (vulnerability area???)
6- Added some recommendations
Author Response
Response to Reviewer 1 Comments
Point 1: Try to enrich the abstract with TDS value, isotopic composition.
Response 1: The author summarized and extracted the corresponding content, and added them to the abstract.
Point 2: More detail the tectonic setting and more explain the faults role in the interconnectivity of tunnels and in the hydrodynamic of groundwater.
Response 2: The author has enriched the “Discription of the study site” about the faults role in each karst system.
Point 3: what about the flow rate of the springs(near/far the faults), is there any relationship(quantity and quality)?
Response 3: The author add some related survey results from batang system which shows that about 70% of the karst phenomenon including springs with a volume of 5 to 500L/s and small karst caves are located at the fault or close to them.
Point 4: More explain the isotopic variation vs altitude( Seeing the ref of Hamed et al., 2008, 2010, 2014).
Response 4: The author has studied the researches, and think they are helpful to improve the revision, and add them in the reference:
Hamed, Y., Ahmadi, R., Demdoum, A., Bouri, S., Gargouri , I., Hamed, B. D., Al-Gamal, S., Laouar, R., Choura, A., 2014. use of geochemical, isotopic, and age tracer data to develope models of groundwater flow: A case study of Gafsa mining ba-sin-Southern Tunisia. Journal of African Earth Sciences, 100(6),418-436.
Hamed, Y., Dassi, L., Ahmadi, R., Hamed, B. D. 2008. Geochemical and isotopic study of the multilayer aquifer system in the Moulares-Redayef basin, southern Tunisia. International Association of Scientific Hydrology Bulletin, 53(6),1241-1252.
Point 5: Is there any karst aquifer pollution by anthropogentic activities ( industrial, agriculture, etc) in the study area ( vulnerability area?).
Response 5: As all the samples were collected before the tunnel construction, the author didn’t find significant pollution from the major ions. Also the tunnels mentioned in the study are usually away from industrial areas, so the author didn’t concentrate on the pollution condition research.
Point 6: Added some recommendations.
Response 6: the author has strengthened discussion part.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper seems to me to be very interesting and important from two points of view:
1. The presentation and justification of the characteristics of the relief and karst dynamics, according to the topographic sectors of the Chinese relief, from SE to NE. The authors present an excellent summary of these characteristics, although some conclusions require more detailed explanations that take into account the complexity and systemic nature of karst functioning;
2. Analysis of the influence of the position and design of railway tunnels on karst dynamics.
However, in my opinion these work objectives are not fully achieved, due to a work organization deficit. Two examples:
1. The study of the importance of railway tunnels, highlighted at the beginning of the work, only occupies a few lines in the last chapter and in the conclusion, and lacks a scientific demonstration of the statements made by the authors...
2. Table 1 presents data from 64 water samples collected for the study, but only about half of them are used in the discussion.
Although my English literacy is low, I think that the quality of work can be improved with an English language review.
Fig. 1 requires a review of the maps, taking into account the accuracy and legibility of the maps contained therein.
The attached text contains a set of general and detailed comments that, in my opinion, can help authors to improve and deepen the scientific quality of the text.
Comments for author File: Comments.pdf
Author Response
Response to Reviewer 2 Comments
Point 1: The study of the importance of railway tunnels , highlighted at the beginning of the work, only occupies a few lines in the last chapter and in the conclusion, and lacks a scientfic demonstration of the statements made by the authors.
Response 1: the author has enhanced the discussion part about the influence of tunnels on the groundwater environment with text and image.
Point 2: Table 1 presents data from 64 water samples collected for the study, but only half of them are used in the discussion.
Response 2: there are 9 tunnels sampled in the study ,the 1st tunnel (pingguo with 7 samples) is located in the first topographic grade, the from the 2nd ( xiaozai) to the 8th (laoshishan) tunnel including 6th Dongfeng tunnel(sample 8 to sample 51) are located in the second topograpic grade, these tunnel samples represents a regional feature. The 9th tunnel (Batang tunnel) with sample 52 to 64 is located in the third topographic grade. Except the sample 59 to 64 are lack of hydrogen and oxygen isotopes, all the samples were used to analysis from Fig.7 to Fig.9.
Point 3: the attached text contains a set of general and detailed comments that, in my opinion, can help authors to improve and deepen the scientific quality of the text.
Response 3:the author has studied the comments and made a series of modifications.
a.misspelling of words or grammar mistake: “condition” in the title, “be formed by karst” in the abutract, et al;
b.redrafted Fig.1, the legend was revised, the boundary of three topographic grades were added, the locations of tunnels were sited, the title of the fig has been renamed;
c.” The barrier effect causes the water table to rise in the upper reaches and the water table to drop in the down reaches (Shin et al., 2008; Deveughèle and Zokimila, 2010).” This paper presents a situation that the tunnel drainage might cause a certain condition: the water level might growing in the inflow direction while the discharge direction water level descending;
- “Since no typical karst landforms emerge, it can be inferred that the karst development is weak in this area, might because it is a karst in a phase of greater youth”;
e.” It means that the karst development phase of the Pingguo System is older than the Dongfeng System, and the karst development of the Pingguo System is stronger than that of the Dongfeng System”, this part has been revised into “The result shows that Pingguo system is more evolved than Dongfeng system, and the karst development of the Pingguo System is stronger than that of the Dongfeng System”;
- All these conditions might cause the vadose zone thinner” than the first grade”;
g.” In addition, the tunnel layout is a notable factor that may cause detailed differences in impacts”, to support the conclusion, the author added some explain and discussion in part 5.3
Author Response File: Author Response.pdf
