The Influence of River Morphology on the Remote Sensing Based Discharge Estimation: Implications for Satellite Virtual Gauge Establishment
Round 1
Reviewer 1 Report
See attached technical review. The discussion for the Results and Discussiom, and Conclusions sections needs to be srengthened.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript “The Influence of River Morphology on Remote Sensing based Discharge Estimation: Implications for Satellite Virtual Gauge Establishment” is scientifically sound and well-structured, written and presented. The methodological part is very clear, indicating the process and the several data sources used for producing the outputs. The results are very well presented. In general, it a very good paper, however I believe that the amelioration of the discussion part, which is rather a synopsis of the methodology and the results, would result to an excellent scientific paper.
Specific comments
Line 66: “sensed river characteristics, such as water level [13] and water area [14]”: I would suggest that the following references to be added in the manuscript, e.g. for water level: Ovakoglou et al. (2016) https://doi.org/10.1016/j.jag.2016.04.007 propose the use of remote sensing data for assessing the bathymetry of lakes.
Lines 68-69: “estimate discharge based on 68 hydraulic geometry [7,15-19]” I would propose the work of Reil et al. (2018) https://doi.org/10.1111/jfr3.12304 to include remote sensing techniques in their evaluation for estimating the riverbed morphology as part of a hydraulic simulation process.
Lines 156: the link (http://hydro.iis.u-tokyo.ac.jp/~yamadai/MERIT_Hy-dro/) for the MERIT HYDRO product is not active.
Line 178-179: “river gradient (G) in this study refers to ratio of elevation difference (H) to the horizontal distance (L).” Unfortunately Figure S1 is not accessible in order to see the performed processes. Thus I would propose to be added in the manuscript as an Annex integrated within the main manuscript.
Discussion. The proposed methodology and outputs should be compared with the outputs (in terms of accuracy, biases, etc) with the work of other scholars that assess river discharges through remote sensing, and the differences and similarities should be mentioned. Finally, the limitations of the research as well as issues that could further ameliorate the final outputs should be part of the discussion part.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
