Quantitative Analysis of Temporal and Spatial Variations of Soil Salinization and Groundwater Depth along the Yellow River Saline–Alkali Land
Round 1
Reviewer 1 Report
The paper is thematically focused on the issue of quantitative analysis of temporal and spatial variations of soil salinization and groundwater depth along the Yellow River Saline – Alkali Land. Overall, the contribution is processed at an average level. I recommend the authors to consistently state the basic units of the SI system, ie mm instead of cm (eg lines 23, 120, 265), and to state the units in the index form m2 (line 49). I consider it very important to complete the discussion, in which the results are insufficiently confronted with work on similar topics. The conclusion also insufficiently characterizes the achieved results. After incorporating these comments, the text can be accepted for publication.
Author Response
Thank you very much for your beneficial comments and suggestions. The corresponding changes have been made in the revised manuscript according to your comments point-by-point. The revised contents are listed behind the response, among them, the line number we responded to corresponds to the "Final Showing Markup" of the revised manuscript:
Point 1:I recommend the authors to consistently state the basic units of the SI system, ie mm instead of cm (eg lines 23, 120, 265), and to state the units in the index form m2 (line 49).
Response 1: Thanks very much for your suggestion on the basic units. All units have been revised in the revised manuscript L.23,50,270,356.
Point 2:I consider it very important to complete the discussion, in which the results are insufficiently confronted with work on similar topics. The conclusion also insufficiently characterizes the achieved results. After incorporating these comments, the text can be accepted for publication.
Response 2: We thank the reviewer for the professional advice very much.We have rewritten the Abstract, and improved Introduction, Discussion and Conclusions in the revised manuscript.
Thank you for your comments on the inappropriate descriptions in our article. It’s a great help in improving this article and in future writing. We hope that these revisions are satisfactory and that the revised manuscript will be acceptable for publication. Thank you again!
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Please see the attachment.
Comments for author File: Comments.pdf
Author Response
Thank you very much for your beneficial comments and suggestions. We have rewritten the Abstract, and improved Introduction, Discussion and Conclusions in the revised manuscript. The corresponding changes have been made in the revised manuscript according to your comments point-by-point. The added contents are marked using the "Track Changes" function in Microsoft Word. The revised contents are also listed behind the response, among them, the line number we responded to corresponds to the "Final Showing Markup" of the revised manuscript:
Point 1:Line 12-16: too long sentence. Make it simple and divide in 2 or more sentences.
Response 1: Thanks very much for your suggestion. Line 38-39 has been rewritten in the revised manuscript L.12-16.
L.12-16：To study the spatial distribution of soil salinization, the temporal and spatial variation of groundwater depth, along the Yellow River saline–alkali land. GIS technology was used to carry out spatial interpolation and quantitative analysis in Shahao, including salinization data obtained before summer irrigation, and groundwater depth data for one hydrological year from long-term observation wells.
Point 2:Line 19-21: general concept, not your findings. Should not include in your abstract.
Response 2: Thanks very much for your suggestion on the abstract. We have rewritten the abstract in the revised manuscript L.19-22.
L.19-22：The high salt content of the Yellow River itself, freeze-thaw change and poor drainage are three important factors causing the high soil salinity along the Yellow River saline–alkali land. Groundwater depth are divided into autumn irrigation, the freezing period and the crop growth period.
Point 3:Line 28: grammatical error.
Response 3: We are sorry for some grammar errors in the text. In the revised manuscript, L.28 has been revised in the revised manuscript L.28-29.
L.28-29：Soil is a natural history complex formed with the combined action of natural factors such as climate, biology, water, and human activities.
Point 4:Line 38-39: Needs to rewrite the sentence in a better structure.
Response 4: Thanks very much for your suggestion. Line 38-39 has been rewritten in the revised manuscript L.36-38.
L.36-38：In traditional soil-type distribution maps, based on limited soil profile points, the soil-type boundaries are delineated, according to factors such as landforms, topography, and the phenological landscape.
Point 5:Line 44: Explain what is “Thiessen polygons” in GIS and how it works?
Response 5: We are sorry for the confusion because of our unclear description.Thiessen polygons is embedded in GIS as a mapping tool by algorithms. Steps: GIS-ArcToolBox-Create Thiessen Polygons <in_features (Distribution of soil sampling points) > <out_features_class> {ONLY_FID | ALL}. In addition,we added detailed description of Thiessen polygons in the revised manuscript L.44-45.
L.44-45：Thiessen polygons is embedded in GIS as a mapping tool by algorithms.
Point 6:Line 49: m2 should be m2. Please provide extra care regarding sub/superscript.
Response 6: We are sorry for ub/superscript errors in the text. In the revised manuscript, m2 has been revised.（L.50）
Point 7:Line 58-60: Please listed all available studies here.
Response 7: We thank the reviewer for the professional advice very much.We added available studies (L.57-60)
L.57-60: Research on saline–alkali land has mainly focused on the control and improvement of soil salinization [12-14], water and salt transportation mechanism[15], the effect of salinization on crop growth [16-17], and the relationship between groundwater depth and mineralization [18].
L.395-403:
- Min W , Guo H , Zhou G , et al. Soil salinity, leaching, and cotton growth as affected by saline water drip irrigation and N fertigation[J]. Acta Agriculturae Scandinavica, 2016:489-501.
- Luo S , Wang S , Lei T , et al. Aggregate-related changes in soil microbial communities under different ameliorant applications in saline-sodic soils[J]. Geoderma, 2018, 329:108-117.
- Guoshuai,W.;Haibin,S.;Xianyue,L.;Qian,Z.;Jiawei,G.;Weigang,W. Analysis of water and salt transportation and balance during cultivated land,waste land and lake system in Hetao Irrigation Area[J].SHUILI XUEBAO:2019,50(12):1518-1528.(in Chinese)
- Li J , Qu Z , Chen J , et al. Effect of Different Thresholds of Drip Irrigation Using Saline Water on Soil Salt Transportation and Maize Yield[J]. Water, 2018, 10(12):17.
Point 8:Line 63: Please quantify “small irrigation areas”
Response 8: Thanks very much for your suggestion. We added description “small irrigation areas below 667 hm2” in the revised manuscript L.65-66.
Point 9:Line 73: What is the reason behind selecting “Shahao” for this study?
Response 9: Because the Hetao irrigation area is one of the three major artesian water diversion irrigation area in China. The average annual the Yellow River diversion is planned to be 5.2 billion m3. The study area Shahao is its trunk irrigation areas,which is a typical area along the Yellow River.We added description in the revised manuscript L.75-78.
L.75-78: The Hetao irrigation area is one of the three major artesian water diversion irrigation area in China. The average annual the Yellow River diversion is planned to be 5.2 billion m3[15]. Shahao is its trunk irrigation areas,which is a typical area along the Yellow River.Therefore, in this study, Shahao was selected for the research.
Point 10:Line 74: What do you mean by “previous field soil surveys”? Any particular timeline?
Response 10: We are sorry for the confusion because of our unclear description. In the revised manuscript, ‘previous field soil surveys’ has been revised(L.78-80).
L.78-80: A map of the regional soil types was drawn by GIS on the basis of field soil surveys, sampling and experimental data
Point 11:Line 88-93: Include
Response 11: Thanks very much for your suggestion. We added sources references of these parameters in the revised manuscript L.99.
L.426-427:
- Jianyu,T.;Jingsong,Y.;YAO Rongjiang,Y.;Xiangping,W.;Guangming,L.;Qiang,C.Effects of Soil Salinity on Nitrogen Transformation in Hetao Irrigation District of Inner Mongolia, China[j]. Soils, 2020, 52(4): 802–810.(in Chinese)
Point 12:Figure 1: I did not see any legend for “Shahao” to identify in this figure. Hangjinhou Banner is not visible in sub-fig. a. Scales need to include in all sub-figures as it is not consistent in all of them.Also, the grids mentioning latitude and longitude are not correct as you used different zoom version in all sub-figures. It is difficult to differentiate among salt, soil sampling points and well points insub-fig. c. What is the unit of elevation in legend? Yellow River needs to show in map.
Response 12: Thanks very much for your suggestion.In the revised manuscript L.106, Figure 1 have been revised.
Point 13:Line 107: What is the importance behind mentioning scale 1:10000? Why 7 samples per square kilometer? Any particular reason?
Response 13: In soil survey, sampling points, profile sampling, soil texture, soil type and code refered the soil survey technical specifications formulated by the Chinese Academy of Sciences, with reference to the former Soviet soil survey technical regulations for the development of Hetao Irrigation Area. This method is more comprehensive and representative.
Point 14:Line 112-114: Reconstruct the sentence.
Response 14: In the revised manuscript, we have reconstructed the sentence.(L.122-123)
L.122-123:We distinguished particle size is greater than or less than 0.01 mm in laboratory, then calculated the percentage of soil particles.
Point 15:Line 122-125: What are the reasons behind this underline?
Section 2.2.1.2. Groundwater depth data: Needs to rewrite. How you collect this data and what kind of instruments used and so on..?
Response 15: Thanks very much for your suggestion. We have rewritten Section 2.2.1.2. Groundwater depth data.(L.131-134)
L.131-134: The groundwater depth is automatically monitored by the water level gauge(HOBO U20-001-02, America) and the wireless transmission water level gauge, which is monitored once every 2 hours, and at the same time, the groundwater depth is manually monitored once every 6 days.
Point 16:Eqn. 1: What is k, n in eqn. 1?
Response 16: Eqn. 1:The meaning of k ,n is the number of the point.(1,2,3...k...n.)
Point 17:2.2.2. Thiessen polygon, 2.2.3. Inverse distance weighting : As far I understand these are tools of GIS that you used for your analysis, so the description should include this information and the reason behind using these tools. You did not use those equation in your analysis rather you use GIS tools that has built-in function. Am I right? Why IDW, not other interpolation like spline,kriging?
Response 17: Thanks very much for your suggestion. Kriging is an interpolation method, according to the characteristics of uncertain points, making an unbiased optimal estimation in a limited area. The IDW method is based on the principle of similarity, i.e., the closer the distance is, the more similar the properties are. The inverse distance interpolation method is suitable for cases in which the sampling points are evenly distributed and cover the entire area. In this study, sampling points were evenly arranged at a density of one sampling point per square kilometer, so IDW can be used for interpolation.In addition,we added detailed description of Thiessen polygons in the revised manuscript L.44-47.
L.44-47: Thiessen polygons is embedded in GIS as a mapping tool by algorithms. It can segment physical quantities with spatial attributes according to limited known points, and provide a good technical platform and a means to draw soil-type maps [8].
Point 18:2.2.1. Data Collection: I will suggest providing all data collection timeline, criteria and other stats in a tabular format.
Response 18: We thank the reviewer for the professional advice very much on the data.. We have added data collection timeline. (L.111-113)
L.111-113: The data involved in this study mainly include soil texture, groundwater depth, and soil salinity and alkalinization (Table 1).
Table 1. Data collection type.
|
Type |
Year |
Depth/mm |
Number of sampling points |
|
Soil texture |
2009 |
0-1000 |
343 |
|
Groundwater depth |
2007-2008 |
/ |
57 |
|
Soil salinity and alkalinization |
2010 |
0-500 |
50 |
Point 19:Line 169: Include “particle analysis” process in methodology
Response 19: Thanks very much for your suggestion. We added 2.2.4 Particle analysis process in methodology.(L.179-185)
L.179-185: 2.2.4. Particle analysis process
1）Place the soil in a cool place to dry, fully roll it with a wooden shovel, then sieve it with a 1 mm sieve;
2) Standardize the sieved soil samples according to the operating procedures of the laser particle size analyzer, and accurately record the results;
3) After completing the measurement test, we used the particle size analysis software（Talwin） to process the data.
Point 20:Table 4: Are you sure about the percentage mentioned in the table? Why these are so small? Please correct them.
Response 20: We are sorry for the confusion of Table 4. In the revised manuscript, we have corrected them.(L.149)
L.149:
Table 4. Particle composition and bulk density of different soil textures in Shahao.
|
Soil texture |
Particle size distribution (%) |
Bulk density |
||
|
0.05~1 (mm) |
0.05~0.002 (mm) |
<0.002 (mm) |
(g /cm3) |
|
|
Sandy soil |
8.1 |
81 |
10.9 |
1.348 |
|
Sandy loam |
3.5 |
72.5 |
24.0 |
1.421 |
|
Clay |
1.0 |
66.0 |
33.0 |
1.535 |
Point 21:Line 176-179: Reconstruct the sentence.
Response 21: Thanks very much for your suggestion. In the revised manuscript, we have reconstructed the sentence.(L.174-178)
L.174-178: In this study, the area covered by each of the 57 long-term observation wells is 40 km2, sampling points were evenly arranged at a density of one sampling point per square kilometer, so this method can be used for interpolation.Moreover the distribution of submersible observation wells is’t dense, the IDW helps to improve the accuracy of the interpolated data.
Point 22:Figure 2: Latitude and Longitude mentioned in figure needs to correct as both maps are in same location (also in Fig.3). Legends need to revise. Soil texture should be soil code according to Table5. Remove “_” from legend. Also, those are not point Thiessen. Provide appropriate name for legend.
Response 22: Thanks very much for your suggestion.In the revised manuscript, Figure 2 and Figure 3 have been revised.(L.216, L.218)
Point 23:Line 202-203: You mentioned “the groundwater depth of Shahao gradually rises from south to north”, however, the figure you provided as Fig.4 does not support your statement. It looks like“Groundwater depth” decreasing from south to north. Terminology needs to correct for whole section 3.2.
Response 23: We thank the reviewer for the professional advice very much. ‘rise’ has been corrected to ‘decrease’ for whole section 3.2 in the revised manuscript L.224,236.
L.224: the groundwater depth of Shahao gradually decreases from south to north,
L.236: so a large amount of the irrigation water seeped deep into groundwater, causing the groundwater depth in the entire study area to decrease markedly.
Point 24:Line 242: It should be Figs. 5 & 6
Response 24: Thanks very much for your suggestion. section 3.2.Line 242 has been revised to ‘Figs. 5 & 6’ in the revised manuscript L.265.
Thank you for your comments on the inappropriate descriptions in our article. It’s a great help in improving this article and in future writing. We hope that these revisions are satisfactory and that the revised manuscript will be acceptable for publication. Thank you again!
Author Response File: 
Author Response.docx
Round 2
Reviewer 2 Report
Authors still need to revise the Abstract and Introduction. It should be well written to provide a conceptual understanding of your article objectives, methodology and findings. Please work on it and revise accordingly. Please give special focus on grammar and sentence structures.
Author Response
Thank you very much for your beneficial comments and suggestions. We have revised the Abstract and Introduction in the revised manuscript (L.16,18-20,22; L.60-61,68-75). The revised contents are marked using the "Track Changes" function in Microsoft Word. Among them, the line number we responded to corresponds to the "Final Showing Markup" of the revised manuscript, and the revised content is added underline in red. We hope that these revisions are satisfactory. Thank you again!
Author Response File: Author Response.pdf
