Temporal Spatial Mutations of Soil Erosion in the Middle and Lower Reaches of the Lancang River Basin and Its Influencing Mechanisms
Round 1
Reviewer 1 Report
REVIEW FORM
Sustainability-1670138
Temporal spatial mutations of soil erosion in the Middle and Lower
reaches of Lancang River Basin and its influencing mechanisms
Comments from the reviewer
- Abstract
- In the keywords, please use the term “Lancang River Basin” instead of “Lancang River”.
- Introduction
- No comment.
- Materials and Methods
- In Figure 1, the name of the province should be “Yunnan Province” instead of “Yun nan Province”.
- Lines 133-134 in the 3rd paragraph of section 2.2. The RUSLE model, please add more reference(s) for the sentence “In this paper, the Wischmeier [30] monthly scale Eq. (2) has been widely used in recent years to calculate the R factor of the ML‐LCR.”.
- Line 143 in section 2.2. The RUSLE model, there is no explanation about the variable “Kepic”.
- In Table 1, the row “Slope gradient (o)”, why there are two numbers in the bracket? Please explain.
- Line 165 in section 2.2. The RUSLE model, the values of a and b were not mentioned and explained in the main text.
- In Table 2, what is the criteria for defining the values of P factor for each land use type?
- Results
- Lines 230-233 in section 3.1. Spatial temporal evolution characteristics of soil erosion, please give the reason and compare with the actual situation for the results illustrated in the sentence “The average soil‐erosion modulus in 2000 was 2.39 × 103 t/(km2∙a), which decreased by 38% in 2005 but then remained basically unchanged through 2010, and then it decreased ~22% during 2010–2015 and increased ~14% during 2015–2019.”.
- In section 3.1. Spatial temporal evolution characteristics of soil erosion, please specify the year 2003 for the sentences “There was a sharp increase in the light‐risk erosion area in the ML‐LRB during 2000–2005,…… (Lines 238-240)” and “During 2000–2019, the moderate‐risk erosion area in the ML‐LRB decreased sharply during 2000 and 2005,…… (Lines 240-243)” .
- Lines 245-246, in section 3.1. Spatial temporal evolution characteristics of soil erosion, the results explained in the sentence “The intense‐ and severe‐risk erosion area had a sharp decrease since 2000 and stabilized after 2005, but there was a year‐to‐year increase since 2015.”, it seems that the results do not correspond to the case of severe‐risk erosion area.
- Line 251 in section 3.1. Spatial temporal evolution characteristics of soil erosion, the results explained in the sentence “……..and a decrease in the moderate‐risk erosion area.”, it seems that the specified result does not correspond to the case of 2019.
- Lines 265-266, in section 3.1. Spatial temporal evolution characteristics of soil erosion, the authors claimed that “…..S2–S4, S6 and S7 had above‐moderate erosion risk,…..”, but in fact the aforementioned subbasins should fall in moderate risk erosion category class as seen from the range indicated in Figure 2.
- Lines 270-271, in section 3.1. Spatial temporal evolution characteristics of soil erosion, the authors claimed that “….., and S2, S5 and S6 had higher average soil erosion modulus than the other subbasins.”, in this case the subbasin S7 should also be included.
- Line 274, in section 3.1. Spatial temporal evolution characteristics of soil erosion, the authors claimed that “….., S8 was in the slight‐risk erosion range,…..”, should it be light‐risk erosion range as seen from the range indicated in Figure 2?
- Line 280, in section 3.1. Spatial temporal evolution characteristics of soil erosion, the authors claimed that “S8 and S9 were within the slight‐risk erosion range,…..”, should it be light‐risk erosion range as seen from the range indicated in Figure 2?
- Line 283, in section 3.1. Spatial temporal evolution characteristics of soil erosion, the authors claimed that “….., whereas the other subbasins had no significant change.”, what about subbasin S2?
- Lines 335-337, in section 3.2. Trends analysis in soil erosion, the authors stated that “…..,but there was a concentrated increasing in soil erosion in Dali City and Xishuangbanna.”, should “Lin cang and Pu'er” also be included?
- Lines 385-388, in section 3.2. Trends analysis in soil erosion, the authors stated that “During 2000–2015, the NDVI in the ML‐LRB increased each year, with the proportion of with vegetation coverage (greater than 80%) of the study area increasing from 25.61% in 2000 to 85.23% in 2015 but falling to 40.40% in 2019.”, what is the reason for the decrease of percentage in 2019, please explain and add the details in the main text?
- Discussion
- Lines 396-401, in section 4.1. Main mechanisms controlling changes in soil erosion, the authors stated that “During 2000–2010, there were no significant changes in land use in the ML‐LRB, but during 2010–2019, there was a huge change in Land use across the study area: ~38.34% of the Arable land changed to Forest, while ~14.39% changed to Grassland; ~10.01% of the Forest changed to Arable, while ~9.11% changed to Grassland and ~15.01% of the Grassland changed to Arable, while ~40.58% changed to Forest.”, please compare the obtained findings with the actual information whether the results are in line with what was happening in the area or not.
- Please provide the reference for the sentence written in Lines 420-422, in section 4.1. Main mechanisms controlling changes in soil erosion as “Despite the large number of hills and mountains in the ML‐LRB, there was a yearly increase of areas with vegetation cover (greater than 80%).”
- Line 449, in section 4.2. Main reasons for controlling mutation in soil erosion, where is Figure 3.11 presented in the main text as the authors referred to?
- The authors located Figure 12 in section 4.2. Main reasons for controlling mutation in soil erosion, however, this figure was not mentioned in this section.
- Conclusion
- No comment.
- General comments
- Since this is an academic publication, please try to avoid the terms, e.g. we, our, etc.;
- Please provide the explanation/full names for some variables indicated in the equations, which were not yet provided.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear editor
The manuscript "Temporal spatial mutations of soil erosion in the Middle and Lower reaches of Lancang River Basin and its influencing mechanisms" was submitted to Sustainability journal. It's an outstanding research about statistical analysis of soil erosion. I have some concerns, finally I recommend to authors that improve the quality of this paper as follows:
- It is strongly recommended that the quantitative results have been highlighted in abstract. So, you have played a significant role in increasing the readers and receiving more citations. I can’t find any information about results.
- There are duplicate words between the title and keywords, such as: “mutations, Lancang River, soil erosion” .Please be careful.
- I believe that you can improve introduction about importance of statistical analysis in soil erosion research. Also you can add some references, I can’t find any reference in line 56-64.
- There is not any information about geology, precipitation, soil in 2-1 section (Study area). Please improve it.
- The research methodology and experiments section are well described, congratulations.
- Results and dissection section are well described, congratulations.
- According to Figure 2, how do you describe the increase of soil erosion in 2019 in the northern part of the region? Please speak about it in discussion.
- I can’t checked plagiarism because the size of PDF was too large (185 MB). Please reduce the size of the article so that I can check.
- Please be sure that all the references cited in the manuscript are also included in the reference list and vice versa with matching spellings and dates.
- Please use more researches related to 2020 and 2021 in references.
Author Response
Dear Editor and Reviewers,
We really appreciate MDPI for giving us the opportunity to revise our manuscript. We also thank the detailed valuable comments on our manuscript of “Temporal spatial mutations of soil erosion in the Middle and Lower reaches of Lancang River Basin and its influencing mechanisms”. We have studied comments carefully and made corrections which we hope to meet with your approval. All the line number in the revision notes are the line number in the clean manuscript. The responses to the reviewer’s comments are as follows:
Response to Reviewer 2 Comments
First of all, thank you very much for your review, your comments are very useful for us.
Point 1: It is strongly recommended that the quantitative results have been highlighted in abstract. So, you have played a significant role in increasing the readers and receiving more citations. I can’t find any information about results.
Response 1: Thanks for your advice, the quantitative results of the study are not emphasized in the abstract because the innovation point of this study is mainly intended to reflect a new research perspective through which to provide a scientific basis for further investigation of the spatial variation of soil erosion.
Point 2: There are duplicate words between the title and keywords, such as: “mutations, Lancang River, soil erosion” .Please be careful.
Response 2: Thanks for your advice, and we have revised in the manuscript.
Point 3: I believe that you can improve introduction about importance of statistical analysis in soil erosion research. Also you can add some references, I can’t find any reference in line 56-64.
Response 3: Thanks for your advice, and we have revised in the manuscript. (L. 59-60 in manuscript with clean)
Point 4: There is not any information about geology, precipitation, soil in 2-1 section (Study area). Please improve it.
Response 4: Thanks for your advice, and we have revised in the manuscript. (L. 116-122 in manuscript with clean)
Point 5: The research methodology and experiments section are well described, congratulations.
Response 5: Thanks for your approval.
Point 6: Results and dissection section are well described, congratulations.
Response 6: Thanks for your approval.
Point 7: According to Figure 2, how do you describe the increase of soil erosion in 2019 in the northern part of the region? Please speak about it in discussion.
Response 7: Thanks for your advice, and we have revised in the manuscript. “The above study found that the dramatic increase in NDVI in the northern part of the LRB in 2019 was the dominant factor for the increase of soil erosion in 2019 in the northern part of the region.” (L. 411-413 in manuscript with clean)
Point 8: I can’t checked plagiarism because the size of PDF was too large (185 MB). Please reduce the size of the article so that I can check.
Response 8: Thanks for your advice, and we have revised in the manuscript.
Point 9: Please be sure that all the references cited in the manuscript are also included in the reference list and vice versa with matching spellings and dates.
Response 9: Thanks for your advice, and we have identified.
Point 10: Please use more researches related to 2020 and 2021 in references.
Response 10: Thanks for your advice, and we have revised in the manuscript.
Reviewer 3 Report
The fundamental problem in estimating soil losses from erosion is the realism of the results obtained. Currently, there are a large number of publications in the scientific literature using various erosion models in estimating soil losses.
The key problem is the evaluation of the quality of the obtained results. How the authors of the article will answer the question: how real are the results of erosion intensity (extremely high in this region of the world!). How can you verify your data?
Author Response
Dear Editor and Reviewers,
We really appreciate MDPI for giving us the opportunity to revise our manuscript. We also thank the detailed valuable comments on our manuscript of “Temporal spatial mutations of soil erosion in the Middle and Lower reaches of Lancang River Basin and its influencing mechanisms”. We have studied comments carefully and made corrections which we hope to meet with your approval. All the line number in the revision notes are the line number in the clean manuscript. The responses to the reviewer’s comments are as follows:
Response to Reviewer 3 Comments
First of all, thank you very much for your review, your comments are very useful for us.
Point 1: The fundamental problem in estimating soil losses from erosion is the realism of the results obtained. Currently, there are a large number of publications in the scientific literature using various erosion models in estimating soil losses.
The key problem is the evaluation of the quality of the obtained results. How the authors of the article will answer the question: how real are the results of erosion intensity (extremely high in this region of the world!). How can you verify your data?
Response 1: Thanks for your advice, as you mentioned, there are numerous publications in the scientific literature using various erosion models to estimate soil loss, and the present study is only a selection of mathematical models among many models applicable to calculate soil erosion in mountainous hilly areas, the accuracy of which has been proven by numerous studies. To better use the Revised Universal Soil Loss Equation (RUSLE) and to ensure the accuracy of the calculation results, the rainfall, vegetation cover, and land-use type data for this study were obtained from the Resource and Environment Data Center of the Chinese Academy of Sciences (https://www.resdc.cn/); the soil properties were obtained from the Chinese soil dataset in the World Soil Database (HWSD); the topographic data were obtained from the Geographic Spatial Data Cloud (https:// www.gscloud.cn/). All data were projected in a uniform coordinate system (WGS_1984_UTM_Zone_47N) and image element size (90×90m).
The accuracy and reliability of the RUSLE model have been verified in many studies. The existing discussions on soil erosion trends have mainly focused on their changes and variability over time. Few studies have addressed the spatial variability of soil erosion and its influencing mechanisms. The focus of this paper is to introduce a mature and reliable method to evaluate the spatial and temporal heterogeneity of soil erosion from a new perspective. This study aims to provide a new perspective by combining Sen's slope estimation with the Mann-Kendall model to investigate the spatial and temporal distribution, spatial abrupt variation characteristics and influence mechanisms of soil erosion, and presents a case study of the middle and lower reaches of the Lancang River Basin (ML-LRB) in China.
At the same time, we would like to apply for more research funds to purchase more detailed data in future studies to further verify the changes of NDVI at mutation points.
Round 2
Reviewer 1 Report
Comments from the reviewer
- Materials and Methods
- Line 165 in section 2.2. The RUSLE model, the values of a and b were not mentioned and explained in the main text.
- In Table 2, please add the criteria for defining the values of P factor for each land use type, i.e. “The values of P factor for each land use were selected based on the criteria of existing domestic and international studies, and also applied to the hilly areas of the Lancang River Basin.”, which was explained by the authors into the main text. Please also add the references as the authors stated that “……based on the criteria of existing domestic and international studies……”
- Discussion
- The authors must follow the suggestion of the reviewer by “comparing the obtained findings with the actual information whether the results are in line with what was happening in the area or not”, for the following sentence.
“In section 4.1. Main mechanisms controlling changes in soil erosion, the authors stated that “During 2000–2010, there were no significant changes in land use in the ML‐LRB, but during 2010–2019, there was a huge change in Land use across the study area: ~38.34% of the Arable land changed to Forest, while ~14.39% changed to Grassland; ~10.01% of the Forest changed to Arable, while ~9.11% changed to Grassland and ~15.01% of the Grassland changed to Arable, while ~40.58% changed to Forest.”
- Please provide the reference for the sentence written in Lines 420-422, in section 4.1. Main mechanisms controlling changes in soil erosion as “Despite the large number of hills and mountains in the ML‐LRB, there was a yearly increase of areas with vegetation cover (greater than 80%).”
- General comments
- The authors must follow the suggestions of the reviewer rather than clarifying in the author's notes, but nothing was made in the revised manuscript.
Author Response
First of all, thank you very much for your review, your comments are very useful for us.
Point 1 - Line 165 in section 2.2. The RUSLE model, the values of a and b were not mentioned and explained in the main text.
Response 1: Thanks for your advice, and we have revised in the manuscript. “α and β are the parameters defining the shape of the NDVI-C curve ". (Line 172 in manuscript with clean)
Point 2: - In Table 2, please add the criteria for defining the values of P factor for each land use type, i.e. “The values of P factor for each land use were selected based on the criteria of existing domestic and international studies, and also applied to the hilly areas of the Lancang River Basin.”, which was explained by the authors into the main text. Please also add the references as the authors stated that “……based on the criteria of existing domestic and international studies……”
Response 2: Thanks for your advice, and and we have revised in the manuscript. P-value was assumed to be: i) 0 for Water area; ii) 0.5 for Arable; iii) 0.9 for Forest and Grass; iv) 1 for Urban construction and Unused land [38-40]. (Line 183 in manuscript with clean)
Point 3: - The authors must follow the suggestion of the reviewer by “comparing the obtained findings with the actual information whether the results are in line with what was happening in the area or not”, for the following sentence.
Response 3: Thanks for your advice, “The present study showed very little difference compared with the results of many scholars on the average soil erosion modulus in the LRB, and the overall spatial distribution trend was generally consistent [8,18,30,46].” The above results on the average annual soil erosion modulus in the Lancang River basin are 1.3×103 t/(km2·a), 1.98×103 t/(km2·a) and 5.35×103 t/(km2·a), respectively, which were somewhat different from the present study result of 1.53×103 t/(km2·a), but the overall spatial distribution trend of was consistent. (Line 238-240 in manuscript with clean)
Point 4: “In section 4.1. Main mechanisms controlling changes in soil erosion, the authors stated that “During 2000–2010, there were no significant changes in land use in the ML‐LRB, but during 2010–2019, there was a huge change in Land use across the study area: ~38.34% of the Arable land changed to Forest, while ~14.39% changed to Grassland; ~10.01% of the Forest changed to Arable, while ~9.11% changed to Grassland and ~15.01% of the Grassland changed to Arable, while ~40.58% changed to Forest.”
Response 4: Thanks for your advice, we draw this conclusion from Figure 10.
Point 5: - Please provide the reference for the sentence written in Lines 420-422, in section 4.1. Main mechanisms controlling changes in soil erosion as “Despite the large number of hills and mountains in the ML‐LRB, there was a yearly increase of areas with vegetation cover (greater than 80%).”
Response 5: Thanks for your advice, and we have revised in the manuscript. (Line 450 in manuscript with clean)
Reviewer 2 Report
Dear editor
The manuscript "Temporal spatial mutations of soil erosion in the Middle and Lower reaches of Lancang River Basin and its influencing mechanisms" was submitted to Sustainability journal as a revision. It’s a nice paper but I have some minor concerns about similarity and abstract, please highlight quantitative results in abstract. I checked plagiarism detection of this research and the similarity is 25% and there are some concerns, please check the attached file.
Best Regards
Comments for author File: Comments.pdf
Author Response
First of all, thank you very much for your review, your comments are very useful for us.
Point 1 The manuscript "Temporal spatial mutations of soil erosion in the Middle and Lower reaches of Lancang River Basin and its influencing mechanisms" was submitted to Sustainability journal as a revision. It’s a nice paper but I have some minor concerns about similarity and abstract, please highlight quantitative results in abstract. I checked plagiarism detection of this research and the similarity is 25% and there are some concerns, please check the attached file.
Response 1: Thanks for your advice, we have highlighted the quantitative results in abstract and reduced the similarity as much as possible. “During 2000-2019, annual soil erosion in the ML-LRB variation ranged from 0 to 7.00×103 t/(km2·a) with a multi-year mean of 1.53×103 t/(km2·a), decreasing year by year from north to south, while an increasing trend began to appear in the central above region after 2015.” (Line 23 in manuscript with clean )
We will also reduce the similarity in accordance with the journal's requirements.
