Groundwater Circulation Mechanism of the Upstream Area of Beiniuchuan River Using Isotope–Hydrochemical Tracer
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe paper “Groundwater circulation mechanism of the upstream area of Beiniuchuan River using isotope-hydrochemical tracer” by Li Chen, Pucheng Zhu, Pei Liu, Wei Zhang, Xinxin Geng and Linna Ma is devoted to the tracing of groundwater circulation patterns across the upstream area of Beiniuchuan River as a typical region for coal mining.
The authors aimed to provide the scientific basis for the management and protection of groundwater resources and water supply security in the coalfield area. They used field investigations, sampling tests, and the applied hydrochemical and isotope techniques including the routine analysis of eight major ions, TDS, and hydrogen and oxygen stable isotopes as well as 3H tritium and 14C radiocarbon.
48 sets of river water, pit water, and groundwater from different aquifers were investigated and classified according to Piper diagram indicating the distinct roles of studied aquifers in the water cycle. The authors used the published data on deuterium in atmospheric precipitation (rainwater) to indicate that the river water and groundwater mainly receive local precipitation recharge and undergo significant evaporation during the recharge process. The radiogenic isotopes 3H and 14C were used to estimate the circulation rate of groundwater.
The manuscript is clear, relevant for the field and presented in a well-structured manner and might be accepted after the minor revision concerning some typos given below:
Line 175: RMWL, not RWML
Figure 4: the abbreviation on the plot should be RMWL and LMWL, not RWML and LWML.
Comments on the Quality of English LanguageEnglish is good, there may be some typos, and a lot of spaces between words has been omitted (possibly during the .doc-.pdf conversion), please check them.
Author Response
1 Line 175: RMWL, not RWML
Reply: This mistake has been modified in manuscript.
2 Figure 4: the abbreviation on the plot should be RMWL and LMWL, not RWML and LWML.
Reply: These mistakes have been modified in manuscript.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe current study investigated the groundwater circulation mechanism in the Dongsheng mining area. The authors did so by carrying out field sampling tests and employed several hydrochemical and isotope techniques, to evaluate the water chemistry, circulation and age. The results indicate that through the analysis of Hydrogen and oxygen isotopes, the local groundwater is primarily recharged by atmospheric precipitation. While the 3H and 14C values show that the Quaternary alluvial and shallow-buried Yan'an formation groundwater, has a fast turnover rate, while the deep-buried Yan'an Formation and Yan'long Formation groundwater have a slower turnover rate. Finally due to the coal mining activities, the water circulation has being affected. The sealing integrity of the Yan'an Formation has been reduced, and precipitation has enhanced the vertical infiltration capacity of the formation, increasing the proportion of groundwater participating in the intermediate flow system.
The current work is interesting and can be used to evaluate the water circulation in the Dongsheng area, ultimately enabling more efficient management of the coal mining impact on the local community. Thusly it is recommended to be published in Water. Although there are some minor issues that need to be addressed and a minor revision is advised.
( 1) Overall the language is in pretty good quality. However there as several cases that spaces are missing between words. Have a look at lines 126, 128, 142, 177, 257 and so on. The authors are advised to reread the main body of the manuscript.
( 2) Line 22: “The 3H and 14C results show that the Quaternary…”. The 3 and 14 should be superscripts as seen in the rest of the manuscript.
( 3) Lines 271- 274: “Only a few Yan’an …. through vertical infiltration.” Here is the main point of the manuscript, where it is being established that there is vertical water circulation. However, it lacks statistical details regarding the significance of samples falling below 1 TU (how much is the “only a few…”). Could it be that the samples with values less than 1 TU are statistically important and the vertical circulation is not that extended? The authors should try to defend their most important statement here, by including any statistical information they can, so that it is clear that there is vertical water circulation.
( 4) The authors should try to extend the discussion around the implications the reduction of the sealing integrity of the Yan'an Formation has. The whole reason this extended investigation was carried out, was to evaluate whether the water circulation was affected due to the mining activities in the region. The results indicate that the water circulation was affected but how that does affect the local community? There is only a really small reference about it at the end of conclusions (lines 337-339). It should be added in the discussion section (4. Discussion) and extended a bit.
( 5) Finally it would be interesting to add some information regarding the contamination levels (heavy metals or anything similar) of the underground aquifers, related to the coal mines in the region. Of course such information might not be available now, but would certainly add to the manuscript and further support the current study findings regarding the presence of the vertical circulations.
Author Response
1 Overall the language is in pretty good quality. However there as several cases that spaces are missing between words. Have a look at lines 126, 128, 142, 177, 257 and so on. The authors are advised to reread the main body of the manuscript.
Reply: These mistakes have been amended in manuscript.
2 Line 22: “The 3H and 14C results show that the Quaternary…”. The 3 and 14 should be superscripts as seen in the rest of the manuscript.
Reply: These mistakes have been modified in manuscript.
3 Lines 271- 274: “Only a few Yan’an …. through vertical infiltration.” Here is the main point of the manuscript, where it is being established that there is vertical water circulation. However, it lacks statistical details regarding the significance of samples falling below 1 TU (how much is the “only a few…”). Could it be that the samples with values less than 1 TU are statistically important and the vertical circulation is not that extended? The authors should try to defend their most important statement here, by including any statistical information they can, so that it is clear that there is vertical water circulation.
Reply: Relevant information has been added in manuscript.
4 The authors should try to extend the discussion around the implications the reduction of the sealing integrity of the Yan'an Formation has. The whole reason this extended investigation was carried out, was to evaluate whether the water circulation was affected due to the mining activities in the region. The results indicate that the water circulation was affected but how that does affect the local community? There is only a really small reference about it at the end of conclusions (lines 337-339). It should be added in the discussion section (4. Discussion) and extended a bit.
Reply: The discussion part has been extended in manuscript.
5 Finally it would be interesting to add some information regarding the contamination levels (heavy metals or anything similar) of the underground aquifers, related to the coal mines in the region. Of course such information might not be available now, but would certainly add to the manuscript and further support the current study findings regarding the presence of the vertical circulations.
Reply: The data regarding the contamination levels of the underground aquifers is being analyzed. These information will be demonstrated in follow-up studies.
