Effects of Seasonal Variation on Water Quality Parameters and Eutrophication in Lake Yangzong
, Yang Zhang 2 and Hucai Zhang 2,*
Round 1
Reviewer 1 Report
General Comments:
The research article is designed to study the “Effects of Seasonal Variation on Water Quality Parameters and 2 Eutrophication in Lake Yangzong”. The author discusses the analysis of the vertical and horizontal spatial distribution characteristics of water quality parameters and nutrition clearly showed that Lake Yangzong undergoes complex seasonal changes.
The discrepancies of the article are mentioned below to improve its quality.
Revisions:
The article abstract needs revisions. Summarize each section of the article very well. Also, mention the methodology of the article.
The introduction section needs extensive revisions with more citations of the relevant references. The authors must include paragraphs about water quality, point and non-point sources of water quality, and advanced monitoring of the water quality, i.e., satellite data and UAVs. I would recommend to the authors to consult and cite the studies of Mazhar et al.
Iqbal, M.M., Hussain, S., Cheema, M.J.M. and Lyul, J., 2022. Seasonal effect of agricultural pollutants on coastline environment: a case study of the southern estuarine water ecosystem of the boseong county Korea. Pak. J. Agri. Sci, 59(1), pp.117-124.
Iqbal, M.M., Li, L., Hussain, S., Lee, J.L., Mumtaz, F., Elbeltagi, A., Waqas, M.S. and Dilawar, A., 2022. Analysis of Seasonal Variations in Surface Water Quality over Wet and Dry Regions. Water, 14(7), p.1058.
Farid, H.U., Ahmad, I., Anjum, M.N., Khan, Z.M., Iqbal, M.M., Shakoor, A. and Mubeen, M., 2019. Assessing seasonal and long-term changes in groundwater quality due to over-abstraction using geostatistical techniques. Environmental Earth Sciences, 78(13), pp.1-12.
Iqbal, M.M., Shoaib, M., Farid, H.U. and Lee, J.L., 2018. Assessment of water quality profile using numerical modeling approach in major climate classes of Asia. International journal of environmental research and public health, 15(10), p.2258.
In the methodology section, the figure-1 should move after the heading of the 2.2 samplings.
L125-126, kindly mention the name of the instrument, which you have used to measure the water quality.
Correctly mention the caption of the figure-1. Something like that, figure-1 shows the study area and sampling location of the lake.
L158-162, you have mentioned about the groups. Kindly move these lines in the methodology section and also convert this information in the form of the Table for clear understanding. In the methodology section, kindly clearly mention the groups and use those groups throughout the article.
L194-195, if you mention the groups and their durations in the methodology section then you don’t need to mention it in the every place. After that, you can use only group name from group-1 to group-4 at the proceedings of the article.
How you have develop the figure-9 and figure-10. Have you get the lake data through any satellite source.? Because you have taken the sample at three points only of the lake? If yes, then you did not mention in the methodology section about the collection of the satellite data.
Explain the figure-11 in your wording for better understanding of the audience and correct the caption and mention the (a) and (b) with the figure.
Revise the conclusion of the article and discuss about every crop and their results.
Author Response
Thanks for the comments by reviewer #1, those comments are all valuable and very helpful for revising and improving our manuscript. We have read the comments carefully and have made correction which we hope meet with approval. The responds to the reviewer #1 comments are as flowing:
Point 1: The introduction section needs extensive revisions with more citations of the relevant references. The authors must include paragraphs about water quality, point and non-point sources of water quality, and advanced monitoring of the water quality, i.e., satellite data and UAVs. I would recommend to the authors to consult and cite the studies of Mazhar et al.
Iqbal, M.M., Hussain, S., Cheema, M.J.M. and Lyul, J., 2022. Seasonal effect of agricultural pollutants on coastline environment: a case study of the southern estuarine water ecosystem of the boseong county Korea. Pak. J. Agri. Sci, 59(1), pp.117-124.
Iqbal, M.M., Li, L., Hussain, S., Lee, J.L., Mumtaz, F., Elbeltagi, A., Waqas, M.S. and Dilawar, A., 2022. Analysis of Seasonal Variations in Surface Water Quality over Wet and Dry Regions. Water, 14(7), p.1058.
Farid, H.U., Ahmad, I., Anjum, M.N., Khan, Z.M., Iqbal, M.M., Shakoor, A. and Mubeen, M., 2019. Assessing seasonal and long-term changes in groundwater quality due to over-abstraction using geostatistical techniques. Environmental Earth Sciences, 78(13), pp.1-12.
Iqbal, M.M., Shoaib, M., Farid, H.U. and Lee, J.L., 2018. Assessment of water quality profile using numerical modeling approach in major climate classes of Asia. International journal of environmental research and public health, 15(10), p.2258.
Response 1:
I have added relevant contents and cited these documents in the article. Thank you for providing these useful references. (line 39-47, 563-574)
Point 2: In the methodology section, the figure-1 should move after the heading of the 2.2 samplings.
Response 2:
The position of the figure has been changed accordingly. (line 138)
Point 3: L125-126, kindly mention the name of the instrument, which you have used to measure the water quality.
Response 3:
I have indicated the name of the instrument (YSI6600V2). (line 167)
Point 4: Correctly mention the caption of the figure-1. Something like that, figure-1 shows the study area and sampling location of the lake.
Response 4:
The title of Figure 1 has been changed as: Study area and sampling sites of lake Yangzong. (line 139)
Point 5: L158-162, you have mentioned about the groups. Kindly move these lines in the methodology section and also convert this information in the form of the Table for clear understanding. In the methodology section, kindly clearly mention the groups and use those groups throughout the article.
L194-195, if you mention the groups and their durations in the methodology section then you don’t need to mention it in every place. After that, you can use only group name from group-1 to group-4 at the proceedings of the article.
Response 5:
Thanks for your suggestion. Only by analyzing the chart we can see the seasonal changes and distinguish the specific months. It is difficult to divide into four groups directly in the method. After some thinking, I decided to change the group to season, and change all the groups in the full text to season, so as to more intuitively reflect the seasonal changes of the lake. (line 183-189)
Point 6: How you have develop the figure-9 and figure-10. Have you get the lake data through any satellite source.? Because you have taken the sample at three points only of the lake? If yes, then you did not mention in the methodology section about the collection of the satellite data.
Response 6:
Thank you for reminding me. The data in Fig. 9 and Fig. 10 are from the monitoring data of the whole lake in the later stage, which I have supplemented in the method. (line 143-145)
Point 7: Explain the figure-11 in your wording for better understanding of the audience and correct the caption and mention the (a) and (b) with the figure.
Response 7:
Thank you for your advice. Figure 11 has been divided into two parts, which is clearer and more intuitive. (line 387)
Author Response File: 
Author Response.docx
Reviewer 2 Report
The presented manuscript is interesting and raises important issues related to the contamination of stagnant waters. However, the authors made a few mistakes which need to be corrected due to the journal's importance.
1. in the abstract, the authors write about arsenic and anthropogenic pollution, especially fertilizers, and in the methodology, there is nothing about the determination of these parameters
2. I am asking for a detailed description of the depth from which the water samples were taken, or the measurement was made from the presented description; it is difficult to understand the authors
A vertical line was set to monitor the water quality at different depths at each site. The first data was measured between 0.1 m to 1 m below the water surface, the last data was monitored 0.5 meters above the bottom of the lake, and other data were collected at one-meter intervals.
3. please describe the figure in more detail 3. why is there a straight line at the measurement points S1, S2, and S3 in 2016 and 2020, it means that there was no variation in oxygen content with depth? it's strange because the colder the water, the more dissolved oxygen it has.
4. Figure 4. Please explain why the 2015 reaction curve ends at a depth of approx. 8 m.
Summing up, I say that the quoted 24 items are not much, and out of 24 items, 20 are in Chinese, so you cannot refer to them. please complete the literature with items in English because in its current form it is to be seriously corrected
Author Response
Thanks for the reviewer #2 comments, those comments are all valuable and very helpful for revising and improving our manuscript. We have studied comments carefully and have made correction which we hope meet with approval. The responds to the reviewer #2 comments are as flowing:
Point 1: in the abstract, the authors write about arsenic and anthropogenic pollution, especially fertilizers, and in the methodology, there is nothing about the determination of these parameters
Response 1:
Thank you for your comment. Actually, there is no mention of arsenic pollution in the abstract. The focus of the article is mainly on the study of hydration parameters and nutrients.
Point 2: I am asking for a detailed description of the depth from which the water samples were taken, or the measurement was made from the presented description; it is difficult to understand the authors
A vertical line was set to monitor the water quality at different depths at each site. The first data was measured between 0.1 m to 1 m below the water surface, the last data was monitored 0.5 meters above the bottom of the lake, and other data were collected at one-meter intervals.
Response 2:
Regarding the setting of the water depth line, I have the following points of view:
- It has been modified to collect surface water about 0.5m below the water surface. The reason is that it is too shallow, and the lake water is easily affected by factors such as ships and precipitation, resulting in data errors.
- Collect a sample every 1m, which is more accurate and can accurately see the relevant laws of water stratification.
- Sampling at 0.5m above the bottom layer is to prevent the disturbance of sediment from interfering with the hydration parameters.
Point 3: please describe the figure in more detail 3. why is there a straight line at the measurement points S1, S2, and S3 in 2016 and 2020, it means that there was no variation in oxygen content with depth? it's strange because the colder the water, the more dissolved oxygen it has.
Response 3:
Thank you for your questions. You are right. There is a great correlation between temperature and DO in winter during 2016 and 2020. Because the water bodies are fully mixed, there is no significant change in temperature, pH, do and other indicators in the vertical direction.
Point 4: Figure 4. Please explain why the 2015 reaction curve ends at a depth of approx. 8 m.
Response 4:
I'm very sorry for the situation of S1 point in April 2015. At that time, there were some abnormal conditions in the equipment, and some data below 8m were lost.
Point 5: Summing up, I say that the quoted 24 items are not much, and out of 24 items, 20 are in Chinese, so you cannot refer to them. please complete the literature with items in English because in its current form it is to be seriously corrected
Response 5:
Thank you for your summary. I found that I did cite too many Chinese documents. Therefore, I revised the citation of the literature. At present, except for some extremely relevant ones that cannot be modified, I have quoted new literatures and added some relevant contents. (line 550-646)
Author Response File: Author Response.docx
Reviewer 3 Report
General: The paper is rejected in its present form and recommended for resubmission after revision.
The paper require improvement aimed at suitability within the frame of acceptable style in scientific-limnology. The professional terms and evaluation of the data require significant improvement.
Specific comments
Lines 18-19: water quality parameters were significantly correlated and probably affected by temperature.
Line 29:water supply and storage are identical
Line 30: change exchange cycle to water exchange is recommended.
Line 34: change trophic levels to trophic status is recommended.
Lines 38-43: Thermal stratification is the result of geographic location and summer-winter climatological differences and the depth of the lake. The seasonal vertical distribution of nutrients accompany the thermal structure dynamics.
Lines 44-46: Algal growth rate and other physiological characterization of living organisms are responding temperature and not vice versa.
Lines 50-60: Data about global distribution of phytoplankton require citations.
Line 61: change nutritional status to trophic status ids recommended.
Line 66: …in their body might be deleted.
Line 94: change elevation by altitude is recommended
Line 97: …daily temperature…values are supportive
Line 102: atmospheric precipitation. .and …Total annual rainfall…and value are supportive
Line 102: sufficient for what?
Line 116: …still high…values are supportive
Line 119: change sites to stations is recommended
Line 123: change points to stations is recommended.
Line 127: ….water quality…define parameters.
Line 135: indicate how much time between sampling and lab.analysis.
Line 150: characteristics might be deleted
Line 151: Indicate briefly what is plateau
Line 158: change curve to pattern is recommended
Line 158-164: A clear summarized presentation of seasonal thermal stratification
with temperature ranges and timing (month) is recommended
Lines 181-185: the evaluation of reasonable effects causing the informed case.
What is horizontally mean (line 181)?
Lines 192-198: For understandable evaluation of the vertical distribution of DO, the thermal structure development and stability which prevent mixing is recommended.
The higher is the temperature differences the stronger is the stratification stablity and DO distribution.
Figure 2 and the entire text as well: The use of professional terms such as thermal structure, chemical structure, Epilimnion, Hypolimnion, Thermocline, Chemocline etc.is ultimately recommended.
Line 210-224: Change layers to stratified (line 211) is recommended.
All those changes require explanation. Indicate day time each sampling because photosynthetic algal activity is light dependent affecting DO, pH, chlorophyll.
Line 208: change was to is …is recommended.
Figure 3:It Is obviously possible that increase of epilimnetic DO is due to photosynthetic enhancement?
Lines 233-247: The relation between EC and salts concentration is obvious, indicate.
Figure 5: Enhancement of EC and salts concentrations in winter is indicated. The possibility of winter floods and intensive inputs in winter are relevant, indicate.
Figure 6: In S1, S2, S3 low chlorophyll at 0-2 m and peaks at 2.5-9 m depths. Did you document algal vertical migration? Did you collect samples at the same day-time in all stations.
Figure 7: The vertical distribution of phycocyanin and chlorophyl are similar. Probably Cyanobacteria are dominant within the phytoplankton assemblages? Indicate.
Line 323-329: The possibility of intensive inputs of TN included in the winter floods, indicate.
Line 330: Change of bottom water to Hypolimnion is recommended.
Lines 330-340: The statement o TN and TP release from bottom or sinking from the Epilimnion require clarification.
Lines 359-362: Probably external import? Indicate.
Lines 372-378: Throughout the entire paper there are no climatological information such as: rainfall, headwater discharges, air temperature, and seasonal (month) frame
of winter-summer etc. critical addition.
Line 370: and can be deleted.
Lines 384-385: The environmental parameters follow the thermal structure and stratification is response to climatological condition.
Line 396: wrong interpretation: DO deletion in the hypolimnion is due to geochemical DO consumption during decomposition and stable stratification prevent mixing.
Lines 399 and 404: these are two obvious well known processes, photosynthetic activity is obviously DO production.
Line 409: But chlorophyll data indicates lower DO ion surface, clarify.
Line 411: CO2 concentration is controlled by organics decomposition but not affected significantly by algal respiration.
Line 414: pH level is mostly controlled by photosynthetic activity.
Line 430: Evaporation is controlled by air temperature and relative humidity, wind regime and less by rainfall.
Line 433-435: Relation between salt concentrations and growth rate of Cyanobacteria should be followed by citations, it is not so commonly documented. Moreover, no data about salts input into the lake are presented.
Line 440: citation is critically required.
Line 442: change of could be to is…is recommended.
Line 451: change of water nutrition change to trophic status is recommended.
Line 454: If so, then what are the differences in external inputs? Did you calculate TN/TP mass ratio in the lake and external inputs, which is significantly relevance? Curiosity: TN/TP (line 480) as 1.3/0.06=22 which is favorable for cyanobacteria.
Lines 458-459: the optional development of TN and TP enhancement in the hypolimnion as a result of particle sedimentation from the epilimnion. Indicate.
Comments for author File: 
Comments.pdf
Author Response
Thanks for the reviewer #3 comments, those comments are valuable and very helpful for revising and improving our manuscript. We have considered your comments carefully and have made correction accordingly. The responds to the reviewer #3 comments are as flowing:
Point 1: Lines 18-19: water quality parameters were significantly correlated and probably affected by temperature.
Response 1:
It has been modified according to your requirements. (line 18-19)
Point 2: Line 29: water supply and storage are identical
Response 2:
Similar words have been deleted. (line 31)
Point 3: Line 30: change exchange cycle to water exchange is recommended.
Response 3:
It has been modified according to your requirements. (line 32)
Point 4: Line 34: change trophic levels to trophic status is recommended.
Response 4:
It has been modified according to your requirements. (line 37)
Point 5: Lines 38-43: Thermal stratification is the result of geographic location and summer-winter climatological differences and the depth of the lake. The seasonal vertical distribution of nutrients accompany the thermal structure dynamics.
Response 5:
It has been modified according to your requirements. (line 48-50)
Point 6: Lines 44-46: Algal growth rate and other physiological characterization of living organisms are responding temperature and not vice versa.
Response 6:
It has been modified according to your requirements. (line 57-58)
Point 7: Lines 50-60: Data about global distribution of phytoplankton require citations.
Response 7:
Thank you very much for your advice. In the article, I mentioned some of the algae in Lake Yangzong. Because the water quality parameters are mainly written, there is no detailed description of algae.
Point 8: Line 61: change nutritional status to trophic status ids recommended.
Response 8:
It has been modified according to your requirements. (line 77)
Point 9: Line 66: …in their body might be deleted.
Response 9:
It has been modified according to your requirements. (line 82)
Point 10: Line 94: change elevation by altitude is recommended
Response 10:
It has been modified according to your requirements. (line 110)
Point 11: Line 97: …daily temperature…values are supportive
Response 11:
Thank you for reminding me. Relevant data has been added and referenced. (line 113-114)
Point 12: Line 102: atmospheric precipitation. .and …Total annual rainfall…and value are supportive
Response 12:
Thank you for reminding me. Relevant data has been added and referenced. (line118-119)
Point 13: Line 102: sufficient for what?
Response 13:
The sufficient rainfall in summer is different from that in winter, so there is a transition between spring and autumn.
Point 14: Line 116: …still high…values are supportive
Response 14:
The expression has been changed and relevant data has been supplemented: The Arsenic content was remained at a moderate level (in 2010, fluctuate around 0.05 mg/L> 0.01 mg/L). (line 135-136)
Point 15: Line 119: change sites to stations is recommended
Response 15:
It has been modified according to your requirements. (line 140)
Point 16: Line 123: change points to stations is recommended.
Response 16:
It has been modified according to your requirements. (line 145)
Point 17: Line 127: …. water quality…define parameters.
Response 17:
Supplementary description has been made: (including WT, DO, Chl-a, pH, conductivity and phycocyanin). (line 149-150)
Point 18: Line 135: indicate how much time between sampling and lab.analysis.
Response 18:
Thank you for reminding me. Generally, our samples will be processed within two hours after they are shipped back. (line 159)
Point 19: Line 150: characteristics might be deleted
Response 19:
It has been modified according to your requirements. (line 175)
Point 20: Line 151: Indicate briefly what is plateau
Response 20:
I'm very sorry. I think plateau lake is a rather vague definition. Some people think that areas with an altitude of more than 1000 m belong to the plateau, and lakes on the plateau are plateau lakes. Some people also think that only when the altitude is above 3000 m can it be regarded as a plateau. So I have no definition.
Point 21: Line 158: change curve to pattern is recommended
Response 21:
It has been modified according to your requirements. (line 183)
Point 22: Line 158-164: A clear summarized presentation of seasonal thermal stratification with temperature ranges and timing (month) is recommended
Response 22:
For seasonal classification, I have supplemented the temperature range corresponding to the four seasons classification. (line 184-188)
Point 23: Lines 181-185: the evaluation of reasonable effects causing the informed case. What is horizontally mean (line 181)?
Response 23:
horizontally means parameters between different monitoring points. The WT difference of the three monitoring points is not large.
Point 24: Lines 192-198: For understandable evaluation of the vertical distribution of DO, the thermal structure development and stability which prevent mixing is recommended. The higher is the temperature differences the stronger is the stratification stablity and DO distribution.
Response 24:
Thank you for your suggestion. It has been modified as required to make it easier to understand. (line 219-220)
Point 25: Figure 2 and the entire text as well: The use of professional terms such as thermal structure, chemical structure, Epilimnion, Hypolimnion, Thermocline, Chemocline etc.is ultimately recommended.
Response 25:
Thank you for your suggestion. Some words have been replaced as required with professional words.
Point 26: Line 210-224: Change layers to stratified (line 211) is recommended. All those changes require explanation. Indicate day time each sampling because photosynthetic algal activity is light dependent affecting DO, pH, chlorophyll.
Response 26:
Change layers to stratified (line 211): It has been modified according to your requirements. (line 240)
The surface water of 0-2m is related to the sampling environment at that time. The water of Lake Yangzong is relatively mobile, and the YSI instrument is unstable on the surface when it is put down. So that the pH value fluctuates greatly just after entering the water.
Point 27: Line 208: change was to is …is recommended.
Response 27:
It has been modified according to your requirements. (line 238)
Point 28: Figure 3: It Is obviously possible that increase of epilimnetic DO is due to photosynthetic enhancement?
Response 28:
Thank you for your question. I think the high content of DO in Epilimnion is due to the large hydrodynamic force, which has little relationship with the photosynthesis of algae, because the chlorophyll content in the surface water is not high.
Point 29: Lines 233-247: The relation between EC and salts concentration is obvious, indicate.
Response 29:
Conductivity has a great relationship with ion concentration. Ions often come from external sources, such as K+ and NO2- plasma in fertilizers. These ions can promote the growth of algae (Deng et al. 2016).
Point 30: Figure 5: Enhancement of EC and salts concentrations in winter is indicated. The possibility of winter floods and intensive inputs in winter are relevant, indicate.
Response 30:
In my opinion, the increase of ion concentration in winter has nothing to do with the flood, because winter is the dry season, and the total water volume of the lake decreases, so the ion concentration increases, and the rivers entering the lake in the South may be merged.
Point 31: Figure 6: In S1, S2, S3 low chlorophyll at 0-2 m and peaks at 2.5-9 m depths. Did you document algal vertical migration? Did you collect samples at the same day-time in all stations.
Response 31:
Thank you for your advice. I did collect samples on the same day, but I did not document algal vertical migration. I think that in Lake Yangzong, due to the large epilimnetic hydrodynamic force, it is not conducive to the growth of algae. However, due to the high transparency, there is still light at the position of 2.5 – 9 m and sufficient DO, so there are more algae.
Point 32: Figure 7: The vertical distribution of phycocyanin and chlorophyll are similar. Probably Cyanobacteria are dominant within the phytoplankton assemblages? Indicate.
Response 32:
It is indeed possible that the chlorophyll and phycocyanin content curves are similar, indicating that cyanobacteria may be the dominant population, but the specific situation may require relevant data on the content of cyanobacteria.
Point 33: Line 323-329: The possibility of intensive inputs of TN included in the winter floods, indicate.
Response 33:
Winter is a dry season with little precipitation, mainly due to the low total water volume of the lake and the high TN content caused by the confluence of the southern rivers. (line 356-357)
Point 34: Line 330: Change of bottom water to Hypolimnion is recommended.
Response 34:
It has been modified according to your requirements. (line 361)
Point 35: Lines 330-340: The statement o TN and TP release from bottom or sinking from the Epilimnion require clarification.
Response 35:
Thank you for your good question. I think TN and TP changes are due to the release of sediment. First, in August 2021, it is summer, and the water stratification phenomenon is obvious. There is no exchange between the upper water body and the lower water body. Therefore, the high content of TN and TP in the bottom layer must be caused by the release of sediment. Second, in December 2020, in winter, the PN and PP contents in the water account for 21% and 45% respectively, which is not high, and the closer to the bottom layer, the higher the TDN and TDP contents, which also shows that this is caused by the release of bottom mud.
Point 36: Lines 359-362: Probably external import? Indicate.
Response 36:
Thank you for your questions. I really ignored the confluence of the rivers entering the lake in the south. In the dry season, the lake water mainly comes from the rivers entering the lake. Therefore, in December 2020, the TN and TP contents at point S1 of Lake Yangzong were significantly high. According to previous data, the TN content of the southern river was 5 times that of the lake water, and the TP was 2 times that of the lake water. However, there is no monitoring data in 2020 and 2021, so we can only speculate.
Point 37: Lines 372-378: Throughout the entire paper there are no climatological information such as: rainfall, headwater discharges, air temperature, and seasonal (month) frame of winter-summer etc. critical addition.
Response 37:
Thank you very much for your advice. Some climatological information has been added in the introduction.
Point 38: Line 370: and can be deleted.
Response 38:
It has been modified according to your requirements. (line 406)
Point 39: Lines 384-385: The environmental parameters follow the thermal structure and stratification is response to climatological condition.
Response 39:
It has been modified according to your requirements. (line 419-421)
Point 40: Line 396: wrong interpretation: DO deletion in the hypolimnion is due to geochemical DO consumption during decomposition and stable stratification prevent mixing.
Response 40:
It has been modified according to your requirements.
Point 41: Lines 399 and 404: these are two obvious well known processes, photosynthetic activity is obviously DO production.
Response 41:
Thank you for your advice. I have made a trade-off between the obvious and the obvious.
Point 42: Line 409: But chlorophyll data indicates lower DO ion surface, clarify.
Response 42:
Thank you for your proposal. The surface water of Lake Yangzong has a large hydrodynamic force, which is unfavorable to the growth of algae. This is also the reason why the do content of surface water is high, but the chlorophyll content is low. (line431-433)
Point 43: Line 411: CO2 concentration is controlled by organics decomposition but not affected significantly by algal respiration.
Response 43:
Thank you for your professional reply. This part has been revised. (line 449-450)
Point 44: Line 414: pH level is mostly controlled by photosynthetic activity.
Response 44:
Thank you for your professional reply. This part has been revised. (line 452-453)
Point 45: Line 430: Evaporation is controlled by air temperature and relative humidity, wind regime and less by rainfall.
Response 45:
Thank you for your advice. What I mean by this paragraph is that precipitation is used to distinguish the rainy and dry seasons of lakes.
Point 46: Line 433-435: Relation between salt concentrations and growth rate of Cyanobacteria should be followed by citations, it is not so commonly documented. Moreover, no data about salts input into the lake are presented.
Response 46:
Thank you for your advice. My statement here is wrong. What I want to show is that the growth of algae is related to the conductivity, and the conductivity is related to the content of ions contained in the lake water. I cited the research of Deng et al. 2016. (line 472-475)
Point 47: Line 440: citation is critically required.
Response 47:
Thanks for your reminder. Relevant references have been cited. A large amount of FeCl3 is used to remove arsenic, so there is a large amount of ferric salt, resulting in high conductivity. (line 483-484)
Point 48: Line 442: change of could be to is…is recommended.
Response 48:
It has been modified according to your requirements. (line 487)
Point 49: Line 451: change of water nutrition change to trophic status is recommended.
Response 49:
It has been modified according to your requirements. (line 498)
Point 50: Line 454: If so, then what are the differences in external inputs? Did you calculate TN/TP mass ratio in the lake and external inputs, which is significantly relevance? Curiosity: TN/TP (line 480) as 1.3/0.06=22 which is favorable for cyanobacteria.
Response 50:
Thank you for your very interesting question. Unfortunately, I don't have relevant data of external sources, so I can't analyze the import of N and P. I'm very sorry.
Point 51: Lines 458-459: the optional development of TN and TP enhancement in the hypolimnion as a result of particle sedimentation from the epilimnion. Indicate.
Response 51:
This is similar to point 35. I think that the increase of N and P content in bottom water should be the result of sediment release, not the result of upper layer sedimentation. The reason is the same as point 35.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Required revisions have been done.
Author Response
Again, we would like to thank you very much for the helpful input that improved the quality of the manuscript greatly.
Reviewer 2 Report
The authors significantly improved the manuscript,
Thank you for adding an article other than just in Chinese.
However, I am still unsatisfied, because the added literature is old, and it would be good to refer to the latest reports.
I believe the authors should still work on the manuscript.
Author Response
Thanks for the comments by reviewer #2, those comments are all valuable and very helpful for revising and improving our manuscript. We have read the comments carefully and have made correction which we hope meet with approval. The responds to the reviewer #2 comments are as flowing:
Point 1: The authors significantly improved the manuscript,
Thank you for adding an article other than just in Chinese.
However, I am still unsatisfied, because the added literature is old, and it would be good to refer to the latest reports.
I believe the authors should still work on the manuscript.
Response 1:
Thank you for your advice. I have updated some old literature, 6 in total (line 577-580, 596-599, 600-602, 606-608, 618-620, 652-654). Some of the quotes are from the Lake Yangzong arsenic pollution incident at that time, and they are consistent with what I wrote, so they are not updated.
Author Response File: Author Response.docx
Reviewer 3 Report
my comments were responded adequatly
Author Response
Again, we would like to thank you very much for the helpful input that improved the quality of the manuscript greatly.
