Evaluation of Soil Loss and Sediment Yield Based on GIS and Remote Sensing Techniques in a Complex Amazon Mountain Basin of Peru: Case Study Mayo River Basin, San Martin Region
, Julio Cesar Minga 2, Jhon Walter Gómez-Lora 2, Víctor Hugo Gallo-Ramos 3,4 and Victor Garcés Díaz 1
Round 1
Reviewer 1 Report
A lot of science and effort was put to apply new methods of estimating soil erosion and sediment yield as advancements from the original USLE.
The authors have shown good understanding of the English language. Except need to say meandering instead of being meandering line 81)
Author Response
Point 1: Are all the cited references relevant to the research? Can be improved.
Response 1: We added references relevanted and additional text in the introduction (lines 31 to 45 and 72 to 85) and in the results and discussion sections to give more consistency to the study.
Point 2: Are the arguments and discussion of findings coherent, balanced and compelling? Can be improved.
Response 2: In order to improved the paper, in the discussion section, we added paragraphs on the potential and actual erosion results and why RUSLE was chosen instead of another model or equation to complement this section. See lines 407 to 412, 459 to 468, 474-481 in the discussion section.
Point 3: Is the article adequately referenced? Can be improved
Response 3: We have updated all references in the references section. A total of 33 references were added that improve the manuscript.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
1. Please check the sentence in line 98. In line 99, the equation might be representative of average soil erosion or average water erosion, not sure.
2. The findings showed low, moderate, and very high erosion. So, it is better to mention the ranges from low to very high instead of very low to very high in line 307.
3. In line 353, I am not sure about the May station. Are you expressing upper Mayo and lower Mayo stations?
4. Considering C factor, the lower Mayo had the low values. I was expecting to get insights into soil erosion in relation to low C factor values in the lower Mayo.
The quality of English is good, clear, and understandable. Some minor changes might be required in some cases.
Author Response
Point 1: Please check the sentence in line 98. In line 99, the equation might be representative of average soil erosion or average water erosion, not sure.
Response 1: we have checked the sentence on lines 98 and 99 and it has been updated.
Point 2: The findings showed low, moderate, and very high erosion. So, it is better to mention the ranges from low to very high instead of very low to very high in line 307.
Response 2: We have considered your comments and have updated the text on line 307.
Point 3: In line 353, I am not sure about the May station. Are you expressing upper Mayo and lower Mayo stations?
Response 3: Yes, we were expressing upper Mayo and lower Mayo ground stations. The sentences was uploaded.
Point 4: Considering C factor, the lower Mayo had the low values. I was expecting to get insights into soil erosion in relation to low C factor values in the lower Mayo.
Response 4: We have added a paragraph on the low C factor values and associated erosion rates in basins of the bajomayo such as cumbaza and zapatero.
Point 5: Are the arguments and discussion of findings coherent, balanced and compelling? Can be improved
Response 5: We improved the arguments and discussion of findings (discussion section) with several citations and references. A total of 33 references were added that improve the manuscript.
Author Response File: Author Response.pdf
Reviewer 3 Report
This paper integrated the RUSLE model with GIS techniques to evaluate soil erosion and sediment production in the Mayo watershed.Its research ideas are clear, the data and materials are reliable, the discussion is sufficient, and provides reference for soil erosion and sedimentation research in similar watershed.Specific suggestions for modification are as follows:
1、2.2 “The evaluation of soil loss in the Mayo river basin can be classified into 4 levels according to the FAO classification”.It is suggested to supplement the four levels of soil erosion evaluation.
2、Figure 7(b)is not reflected in the paper, it is suggested to supplement the explanation.
3、 Discussion : ”In addition, from the review of local literature, no information on sediment estimates in the Mayo river and erosion rates were available.”Lack of literature support, it is suggested to supplement literature.
4、 GIS technology appears frequently in the paper, so it is suggested to add it to the keywords.
5、 The table layout in this paper is chaotic, and it is suggested to adjust it.
6、 Figure 8 is named the same as Figure 9, but the content is different. It is recommended to change the name for its specific area.
7、 Figure 10 is not illustrated in the article.
8、 Formula (2) It is difficult to distinguish between middle-aged rainfall and monthly rainfall, so it is suggested to add subscripts to distinguish.
Moderate editing of English language
Author Response
Point 1: 2.2 “The evaluation of soil loss in the Mayo river basin can be classified into 4 levels according to the FAO classification”.It is suggested to supplement the four levels of soil erosion evaluation.
Response 1: We updated the paragraph according to the 4 levels of soil erosion classification of FAO.
Point 2: Figure 7(b)is not reflected in the paper, it is suggested to supplement the explanation.
Response 2: The description has been supplemented for figure 7a and 7b.
Point 3: Discussion : ”In addition, from the review of local literature, no information on sediment estimates in the Mayo river and erosion rates were available.”Lack of literature support, it is suggested to supplement literature.
Response 3: We added supplement literature about erosion rates in silimar regions to Mayo river such as Amazonas and Lamas.
Point 4: GIS technology appears frequently in the paper, so it is suggested to add it to the keywords.
Response 4: we added GIS such as keyword.
Point 5: The table layout in this paper is chaotic, and it is suggested to adjust it.
Response 5: The table layout has been improved according to comment.
Point 6: Figure 8 is named the same as Figure 9, but the content is different. It is recommended to change the name for its specific area.
Response 6: We changed the name in both figures.
Point 7: Figure 10 is not illustrated in the article.
Response 7: We added citation of Figure 10 in the article.
Point 8: Formula (2) It is difficult to distinguish between middle-aged rainfall and monthly rainfall, so it is suggested to add subscripts to distinguish.
Response 8: We added subscripts to distinguish between monthy and annual rainfall.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments to the authors (if any)
I am writing in regard to manuscript ID sustainability-2370962 entitled “Estimation of Soil Erosion and Sediment yield using the Modified Revised Universal Soil Loss Equation through GIS and Remote Sensing techniques in the Mayo river basin, San Martin region – Peruvian Amazon,” which was submitted to the Sustainability MDPI. The subject addressed is within the scope of the journal.. After careful review, I have a major revision that I would recommend the author consider:
11. Please change the title of the paper to avoid similarity with the work of Chuenchum et al. (2019)
Chuenchum, P., Xu, M., & Tang, W. (2019). Estimation of soil erosion and sediment yield in the Lancang–Mekong river using the modified revised universal soil loss equation and GIS techniques. Water, 12(1), 135.
22. The abstract need to be reformulated (the problem and conclusion have been much discussed), please add the significant results.
33. The introduction is too short, an expanded version is needed (such as the global problem, LULCC impact on the quality and quantity of water, methods, and technology used for assessing the problem, and the importance and aim of the study)
44. The language of all figures must be written in English
55. The legends of all figures are not clear
66. The abbreviations included in all figures must be discussed
77. 2.2. RUSLE, please write the words, not abbreviations
88. What is the period of study of this paper, one year of data is not significant and sufficient to provide managers and decision-makers with good information for better planning. This suggestion need be considered
99. How validated the SWAT model between calculated and observed sediment yield data
110. How the authors evaluate the efficiency of the simulated data in the SWAT model (calibration, validation, and sensitivity analysis), where the SWAT includes several parameters
111. LULC map was not included in the analysis; NDVI does not make any sense. Please add LULC maps for your study period.
112. The comparison of flow calibration and validation in the SWAT model must be discussed
113. The statistical parameters of observed and calculated sediment yield and estimation errors for the study area must be added
114. What is the R2 result between NDVI and C factor
115. The results section must be more developed.
116. Please update your references list
Comments for author File: Comments.pdf
Extensive editing of English language required
Author Response
Point 1: 1 Please change the title of the paper to avoid similarity with the work of Chuenchum et al. (2019) Chuenchum, P., Xu, M., & Tang, W. (2019). Estimation of soil erosion and sediment yield in the Lancang–Mekong river using the modified revised universal soil loss equation and GIS techniques. Water, 12(1), 135.
Response 1: We changed the title for “ Evaluation of Soil Loss and Sediment yield based on GIS and Remote Sensing Techniques in a complex amazon mountain basin of Peru: Case study Mayo river basin, San Martin region”.
Point 2: The abstract need to be reformulated (the problem and conclusion have been much discussed), please add the significant results.
Response 2: In order to reformulated the abstract, we added sifnificant results in lines 25 to 30 and 34 – 36.
Point 3: The introduction is too short, an expanded version is needed (such as the global problem, LULCC impact on the quality and quantity of water, methods, and technology used for assessing the problem, and the importance and aim of the study).
Response 3: The introduction was expanded in lines 44 to 58 (global problem, land degradation), in lines 85 – 98 (methods, and technology used), 99 to 106 (importance) and 112 to 116 (objectives).
Point 4: The language of all figures must be written in English.
Response 4: All figures were updated to English.
Point 5: The legends of all figures are not clear.
Response 5: The legends were updated.
Point 6: The abbreviations included in all figures must be discussed.
Response 6: We discussed the abreviations in all figures. Please, see xx to xx lines.
Point 7: RUSLE, please write the words, not abbreviations
Response 7: Your suggestion has been considered and updated.
Point 8: What is the period of study of this paper, one year of data is not significant and sufficient to provide managers and decision-makers with good information for better planning. This suggestion need be considered.
Response 8: We added the period of data (1981 to 2019) in the text (lines 294-295). The results show the average erosion values in the Mayo basin and its watersheds.
Point 9: How validated the SWAT model between calculated and observed sediment yield data.
Response 9: In lines 489-491, we mentioned that the sediment yield results are estimated values that need to be calibrated, but due to the lack of a hydrometric station with historical data this has not been done.
Point 10: How the authors evaluate the efficiency of the simulated data in the SWAT model (calibration, validation, and sensitivity analysis), where the SWAT includes several parameters.
Response 10: It has not been possible to evaluate the efficiency of the information simulated in SWAT because there was insufficient historical information in the study area.
Point 11: LULC map was not included in the analysis; NDVI does not make any sense. Please add LULC maps for your study period.
Response 11: Knijff, J. (2000)[1], Castro, I. (2013)[2] and Durigon et. al., (2014)[3] mention the use of NDVI as an alternative for estimating C-factor values in soil erosion.
In this sense, the equation proposed by Durigon et. al., (2014) was used because it was calibrated for tropical watersheds with heavy rainfall such as the study area, so the LULC map was not considered.
Point 12: The comparison of flow calibration and validation in the SWAT model must be discussed.
Response 12: It has not been possible to evaluate the efficiency of the information simulated in SWAT because there was insufficient historical information in the study area.
Point 13: The statistical parameters of observed and calculated sediment yield and estimation errors for the study area must be added.
Response 13: It has not been possible added stastistical parameters of sediment yield because there was insufficient historical information in the study area for calibrated.
Point 14: What is the R2 result between NDVI and C factor.
Response 14: The R2 result between NDVI and C factor is 0.9
Point 15: The results section must be more developed.
Response 15: The results section was more developed. In lines 307 to 313 and 329 to 333.
Point 16: Please update your references list
Response 16: We have updated all references in the references section. A total of 33 references were added that improve the manuscript.
[1] Knijff, J.; Jones, R.; Montanarella, L. Soil erosion risk assessment in Europe. Technical Report 2000. European Union, Joint Research Centre European Commission. Available online: https://www.unisdr.org/files/1581_ereurnew2.pdf (accessed on November 13, 2022).
[2] Castro, I. Estimación de pérdida de suelo por erosión hídrica en microcuenca de presa Madín, México. Ing. Hidráulica y Ambiental. 2013, 34, 3-16.
[3] Durigon, V.; Carvalho, D.; Antunes, M.; Oliveira, P.; Fernandes, M. NDVI time series for monitoring RUSLE cover management factor in a tropical watershed. Int. J. Remote Sens. 2014, 35, 441–453.
Author Response File: Author Response.pdf
Reviewer 5 Report
# Introduction and Novelty
- The authors must provide a novelty statement within this topic.
- Only 12 citations on this topic provides a shallow overview of the topic. The authors could provide some overview of:
- Mayo river basin previous works regarding erosion monitoring.
- Information on the rate of water erosion in areas of the neotropical realm.
# References
- The cited references are majorly used for the construction of the model. The state of the art review could be improved as mentioned previously. Nevertheless, the number of references is satisfactory.
# Applied Methodology
- Please, improve the resolution of all figures particularly on what touches the written information on it.
- Please provide information of authorship on all figures. In author made, state that and present the software and database used.
- If Figure 1 is author made, it would be interesting to present first the GIS information.
# Results and Discussion
- In Line 232 replace “The following figure” for “Figure 2”.
- Figure 3 presentation is missing. Figure 3b is only mentioned after Figure 4. This type of thing must be reorganized. Figures 5, 6 and 10 also are not presented in text.
# Overall
- The manuscript has interesting ideas and, after polishing could be an interesting reference in the future.
The authors could use tools like Grammarly to implement some corrections on the manuscript to present a new version of it with a more concise text.
Author Response
Point 1: # Introduction and Novelty
- The authors must provide a novelty statement within this topic.
- Only 12 citations on this topic provides a shallow overview of the topic. The authors could provide some overview of:
- Mayo river basin previous works regarding erosion monitoring.
- Information on the rate of water erosion in areas of the neotropical realm.
Response 1:
We added 4 references provided mainly information about soil erosion by water in similar regions to study area. In addition, the autors mencioned that is scarce information on soil erosion by water in the Mayo basin, and this work is a more local estimate of the erosion rate. A total of 33 references were added that improve the manuscript.
Point 2: # References
The cited references are majorly used for the construction of the model. The state of the art review could be improved as mentioned previously. Nevertheless, the number of references is satisfactory.
Response 2: We have improved the state of the art review, as can be seen at 44 to 58, 77 to 79, 86 to 99 lines. So, the number of references increase by 30.
Point 3: # Applied Methodology
- Please, improve the resolution of all figures particularly on what touches the written information on it.
- Please provide information of authorship on all figures. In author made, state that and present the software and database used.
Response 3: We have improved the resolucion of all figures in the text and detailed the sources of datasets as well as the software used for the elaboration of the RUSLE factor maps.
Point 4: - If Figure 1 is author made, it would be interesting to present first the GIS information.
Response 4:
In section 2 Materials and methods, We have detailed the sources of GIS datasets as well as the software used for the elaboration of figure 1 and RUSLE factor maps.
Point 5: # Results and Discussion
- In Line 232 replace “The following figure” for “Figure 2”.
- Figure 3 presentation is missing. Figure 3b is only mentioned after Figure 4. This type of thing must be reorganized. Figures 5, 6 and 10 also are not presented in text.
Response 5: Following the reviewer's comments, line 232 and Figures 3, 5, 6 and 10 have been updated. All figures have been properly mentioned.
Point 6: # Overall
- The manuscript has interesting ideas and, after polishing could be an interesting reference in the future.
Response 6:
The manuscript was polished following all comments and suggestions. We are considering that will be an interesting reference in the future, especially for the decision makers in the Mayo river in order to preserve its natural resources.
Author Response File: Author Response.pdf
Round 2
Reviewer 4 Report
Comments to the authors (if any)
I am writing in regard to manuscript ID sustainability-2370962 entitled “Evaluation of Soil Loss and Sediment Yield based on GIS and Remote Sensing Techniques in a Complex Amazon Mountain Basin of Peru: Case Study Mayo River basin, San Martin Region,” which was submitted to the Sustainability MDPI. We think the authors for the improvement that have been done during the first round of revision.
Comments
1. Lines 30-43 must be compressed into one paragraph
2. The introduction was not well improved, please read my first comment.
3. Please update your references list with a paper for the years 2022 and 2023.
Comments for author File: Comments.pdf
Author Response
Response to Reviewer 4
Comments (round 2)
Point 1: Lines 30-43 must be compressed into one paragraph
Lines 30 – 43 have been compressed.
Point 2: The introduction was not well improved, please read my first comment.
The introduction was improved. In following sentences:
- In lines 44 to 66 (global problem)
- In lines 57 to 63 and 83 to 85 (LULCC impact on the quality and quantity of water)
- In lines 108 to 119 (methods and technology used for assessing the problem)
- In lines 128 to 137 (the importance and aim of the study)
Point 3: Please update your references list with a paper for the years 2022 and 2023.
We updated references list with papers for 2022 and 2023. In total, we added 4 news references.
Author Response File: Author Response.pdf
