Modelling of Nutrient Pollution Dynamics in River Basins: A Review with a Perspective of a Distributed Modelling Approach
Round 1
Reviewer 1 Report
The objective of this paper was to review existing process-based models to simulate nutrient pollution dynamics and provide a future research direction. Overall, the quality of the article is good, and it can provide new information in the research field. However, there are a few minor issues that need to be addressed.
Page 1, lines 34-36: “The toxic algal bloom outbreak has increased in the Murray-Darling Rivers, the largest basin in Australia, which has vast socio-economic and environmental impacts (Hannam, 35 P, 2021).” This statement seems a little out of context. Please move this sentence further down the paragraph after the UK example (lines 43-44).
Page 4, lines 155-156: I noted that the authors cited Shrestha et al. 2006 to refer to the AnnAGNPS model. However, that is a model application model. Please provide the original citation (that describes the model development) for the AnnAGNPS model here?
Page 5, line 236: I noted a typo here. Please change “SAWAT” to “SWAT”.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This manuscript presents a review of nonpoint source pollution models. I certainly think this manuscript fits the scope of journal very well and the manuscript itself is well organized. I have a couple of comments for the authors to consider to further improve this manuscript.
- Line 80-85: There have been a number of reviews in the literature that summarize and compare different NPS models. The authors made an attempt here to emphasize that they “highlighted the prospect of process-based modelling compared with others, particularly the capacity in determining the fate of nutrient in higher temporal and spatial resolution and dealing with climate change application.” I think this is a very important claim and the paper should be written to support this claim. However, I don’t see any discussion of “climate change application” in the section that describes the various types of models.
- Line 97: Not all the models in the paper (here and subsequent sections) are provided with their full names, which I think can be fairly easily resolved. They can be provided either in the tables or in the manuscript text where they are first mentioned.
- Line 65-68: Provide a few examples on such international/national organizations.
- Line 87: There are two section 1 in the manuscript. Make the 2nd one Section 2.
- Line 183-185: Does SPARROW involve these techniques? Please verify.
- Line 212: Why “the structure does not allow for future advancement”? This is unclear to me.
- Line 276: I encourage the authors to greatly expand this section “Research gap analysis over basin-scale modeling”. It will be a great service to the community.
- Section 3 and 4: I think these two sections can be merged to be a single section. Moreover, it is not clear to me why the authors chose to showcase this particular model (IISDHM). What’s the purpose?
- Line 336: Co-relation or correlation?
- Figure 4: There is no regression equation on the left panel. There is no unit for the y-axis on the right panel.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors have revised the manuscript substantially according to my previous comments. I don't have additional comments.
