Sediment Transport Capacity in a Gravel-Bed River with a Sandy Tributary

Round 1

Reviewer 1 Report

This paper is very close to ready for publication. I have made comments on the paper. Where I have highlighted sentences, I suggest a rewording for clarity. The quality of figures 1 and 2 leaves much to be desired, so I would suggest you improve them. You could combine 1 and 2, making 1 an inset in a larger and less messy version of 2 with all necessary indicia of cardinal directions and scale.

Comments for author File: Comments.pdf

Mostly misplaced "the" s. Also in listing the sediment transport algorithms considered, these should not start with a ":" but as a new sentence for each.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Title: Sediment transport capacity in a gravel river with a sandy tributary 

This study uses a group of sediment transport equations (i.e. Meyer-Peter and Muller, Parker, Engelund and Hansen, Ackers and White, and Yang’s) into the actual Tagus – Alberche rivers confluence. It has potential to give some insights to the environmental engineers to predict the sediment transport, especially to single out which tested model/equation is the best for the investigated field data. However, after reading, this paper presents some short-comings that need to be overcame to make sure its standard aligns with this journal. Sediment transport is a complex event, hence some of the key factors need to be at least discussed in this paper to give confidence to the readers. Hence, I suggest below points for revision:

1. Abstract needs to be more precisely argued. Besides confirming Yang’s model is the best, the authors need to also explore the percentage errors (of each and every model), which parameter(s) within the selected model has the key effect to the results, etc.     

2. The introduction: It should more clearly portray the novelty of this study. Besides, the motivation of doing such research has to be also located here. This is important, as those utilised sediment transport equations have been discovered and fully tested in a lot of literature. In the view of this, what is the real novelty?    

3. This study employs a range of existing equations in its modelling part. They are not novel as they had already been tested a lot of times in numerous papers/books. To use the old equations, the authors need to show good understanding to them by doing a parameter analysis. This will identify the key parameters used for model adjustment/fitting.  

4. Continue from previous point, sediment transport is a complex issue, especially in the actual field study. One of such non-defined factors to affect river flow/sediment transport is its bedform. Some advanced techniques, such as water-worked bed, has been proposed to study it. This effect needs to be discussed with appropriate literature.  

a) Examining the physical components of boundary shear stress for water-worked gravel deposits. EARTH SURF PROC LAND, 35(10), 1240-1246.

b) Velocity Profile and Turbulence Structure Measurement Corrections for Sediment Transport-Induced Water-Worked Bed, Fluids (MDPI), 6(2), Article No. 86, pp. 1-11.

c) Velocity Distribution and 3D Turbulence Characteristic Analysis for Flow over Water-Worked Rough Bed, Water (MDPI), 2017, 9(9), Article No. 668, pp. 1-13.

5. Other relative factors include the irregularity of channel-form, and turbulence effect. They need to be explored in this paper to give a preliminary understanding, besides the sediment transport modelling.   

6. Conclusion is too long and has to be made more concise. Also the bullet-point form has to be converted into proper text.   

The language, and sentencing need improvement to minimise the grammatic error. 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

After reading the revised version, I think the authors has invested a lot of efforts to improve it. I hence suggest accepted at current form.