Global Analysis of the Cover-Management Factor for Soil Erosion Modeling
Round 1
Reviewer 1 Report
Coverage management factor (C factor) is an important parameter for quantifying soil erosion. The accuracy of C factor value is very important for predicting soil erosion in the study area. High-precision C factor value will help to formulate effective soil conservation measures to ensure sustainable land use and environmental protection. This paper summarizes and discusses the published articles related to C-factor quantification methods. This topic has certain research value. However, this paper needs to carry out more in-depth research in the following aspects :
1. When searching for published literature, will there be limitations in only involving the two keywords ' USLE ' and ' RUSLE ', resulting in incomplete collection of literature, which in turn affects the establishment of the database, making the analysis of C factor incomplete ?
2. In lines 202-204, ' Is it recommended to combine Eq.11 and Eq.12 to quantify large-scale C factors including tropical regions ' ? Can an example be added to illustrate the scientificity and feasibility of the proposal ?
3. The whole article only points out that the resolution of satellite images will affect the accuracy of C-factor values. Whether the C-factor values calculated based on high-resolution satellite images can be compared with the C-factor values calculated from low-resolution satellite images will be more convincing.
Reviewer 's Conclusion : Revised for Retrial
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Author Response
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Author Response File: 
Author Response.docx
Reviewer 2 Report
The authors of this paper implement a very interesting “systematic review” of the methods used by the academic community worldwide for quantifying the C factor. The C factor is an indispensable part of the USLE/RUSLE type of equations estimating soil erosion. At the same time, the C factor is the part of the equation most probably to be affected by human activity and highly influenced by agricultural and conservation policy. Thus, the paper is very relevant, and at the heart of the global soil erosion discussion.
The paper is well-developed, structured around its objectives, concise, and comprehensive. It provides a meaningful classification of methods in 6 broad categories and discusses the results of the various works in each one of the categories.
The paper is based on a very extensive review (847 papers) that established an extensive database. In my opinion, the next step is a meta-analysis of the results and attempting to fit a more robust model based on collected covariates (location, publication year, size of the study area, land-use types and C factor estimation methodology). Such a meta-analysis will increase the value added of the created database and will take the results of the present systematic review one step forward.
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
Dear Authors,
The article is valuable with the examination of this huge number of publications analyzed.
I have a feeling that comparing the average of the C factors with the inclusion of all used values is pointless (see e.g. Figure 4). I suggest considering removing these parts or, at least discussing them in more detail, giving some hints why the similarities apply and how to handle these similarities.
I suggest the inclusion of more discussion about the data in the manner of showing the differences as you do in Lines 161-165. Where were the smallest and largest values and for what reason?
I also suggest the inclusion of various values of the given groups, e.g. what magnitudes belong to certain crops, or crop rotations or monocultures/non-monoculture values.
The same applies to the other categories, e.g. forests are known to provide different cover, only considering the continental climate, deciduous and pine forests differ a lot, when they are in their natural state, obviously, and you also have artificial forest discussed, so, you are aware and the readers also, I assume, so I suggest adding more in-depth details about your analyses.
It would mean a tremendous added value.
Considering crops themselves, as the major influencing factors of soil water erosion must be discussed in more detail. Just comparing legumes with corn and telling that a similar average was found in the literature is not good information without further explanations, as corn rows are normally 70 cm apart while legumes are known to have a much thicker row, so simply telling that their C factor is similar is misleading.
I think.
So, I need to give a major.
Best regards, Reviewer X
I think English is basically OK!
However, I am not a native speaker.
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The authors have fully addressed the review comments in the revised version.
