Identify the Impacts of the Grand Ethiopian Renaissance Dam on Watershed Sediment and Water Yields Dynamics

Round 1

Reviewer 1 Report

Dear authors,

The manuscript presents an important analysis of the Impacts of the Grand Ethiopian Renaissance Dam on Watershed Sediment and Water Yields Dynamics in the Blue Nile, Ethiopia. The article fits the scope and is unpublished for the study region. It is an interesting manuscript, but the introduction, figures and description of the methodology must be improved. It presents a case study and, as far as I can be competent to judge, it is a good paper. The manuscript can be accepted after attending the suggestions. Next, I place my suggestions:

Lines 2-4: The title can be reduced, consider not being very specific from the study area, so the reader will be encouraged to review the abstract. (Is not a mandatory, I leave it at the discretion of you).

Line 25: Keywords must be separated by point coma

Lines 47-49: Here it would be good to know the extension of the dam and the capacity of generation.

Lines 27-82: The introduction is poor in extension, development and appointments. I suggest expanding this section, a good approach is to place a paragraph at the beginning the general context more context related to research. Large dams also cause impacts on the Land Use and Land Cover and socioeconomic. I suggest adding a context of these relationships. You can check the following papers so you can generate this context: https://doi.org/10.11137/2019_1_74_86, https://doi.org/10.5801/ncn.v15i1.895, https://doi.org/10.3390/su14031630.

Lines 78-82: The goal of the paper is not clear. I suggest leaving only the general objective and close the paragraph with a justification of what the study will be the study

Line 87: Here you should already place geospatial technologies (at least as it is written, programs are expected to be confirmed)

Line 101: Figure 1 needs to be improved. Maps of the study area is more common to see vector data than a DEM. You can leave the DEM, but the colors must be modified. Preferably, do not use the blue color in the representation of DEM. This thinking more of your non-African readers, who may not be very familiar with the territory of Africa. The legend must be unified and improved.

Lines 466-494: This section should be synthesized. Comment exclusively as relevant. This section must respond to the objective of the paper, since the objective is not clear, I do not see the conclusions very clearly.

The citations must go in the format required by the journal

Author Response

Dear Reviewer,

Thank you very much for your thorough work and useful comments, which have been carefully considered and incorporated into the revised manuscript.

Author Response File: Author Response.docx

Reviewer 2 Report

The authors showed, indeed, the involvement into a valuable ,and required from environmentally sound perspective, estimation of the dam significance to changing runoff conditions and erosion intensity. The subject of the paper is no doubt considered as interesting, but the ,,state of the art” should be better presented in the introduction. Could there kindly be any references to the current literature sources? The title is practical, indeed, pointing at an intetesting case study, but from a viewpoit of a scientific paper it seems too local, directed only at a single case , not depicting a broader problem.

Methodology- AWY model- at first it is kindly required to explain the term ,,AWY”? Is it a common , widespread term used in hydrological sciences/ geosciences or water management? Isn’t the proposed model too general? The averge yield or runoff usually requires complex models , like SWAT to be estimated on a catchment scale. Is there any impact of soil cover /soil  deposits on runoff or yield? - such as percolation or interflow or leakage to groundwater.

                                                ,, Z is a seasonality factor that captures the precipitation and other hydrologic  variables of the watershed at the local scale”- how all the physiographic or hydrologic variables can be captured by a single parameter?

Was there a calibration of the hydrologic model?

As far as I am concerned the topic is nice and interesting, but does not reveal any signs of scientific novelty. The impact of a large dam is a vital issue and requires environmental impact statemets etc., but in a scientific work should serve a firm goal. The authors, to the best of my belief, draw sufficient attention to the environmental impact assessment and the role the dam would play for hydrologic and sediment regime, but a hypothesis supported by a literature review ought to come first.

Author Response

Dear Reviewer,

Thank you very much for your thorough work and useful comments, which have been carefully considered and incorporated into the revised manuscript.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Dear authors,

This is the second revision of the manuscript, the authors attended to all the suggestions made. It presents a case study and, as far as I can be competent to judge, it is a good paper.

Author Response

Thank you very much for your thorough work and useful comments in the first round, which help much to improve the revised manuscript.

Reviewer 2 Report

The paper was substantially revised showing the authors' involvement. Please refine the conclusions adequate to the corrected, new introduction and aims of the paper that you stated. In the current verison the conclusions do not reflect the broader goal you provided e.g. on sustainable development security in respect of the dam environmental impacts. How the sustainable management scenario will be put into practice? Other points are ok.

Author Response

Thank you very much for your thorough work and useful comments, which have been carefully considered and incorporated into the revised manuscript. All the changes made in the revised version were highlighted in red color. We have revised the conclusions section of the manuscript based on the revised version of the introduction and the main thesis of the work (from lines 484 to 486 and 492 to 495).

Note: The manuscript has been thoroughly revised, and corrections were made where necessary.