Influencing Factors and Prediction of Turbine Sediment Concentration in Pure Pumped-Storage Power Stations on Sediment-Laden Rivers

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1.    The author's affiliation is not given.
2.    The specific research area (which PSPS) should be reflected in both the title, the abstract and the introduction. This is because empirical formulas have limitations and are not universally applicable.
3.    The von Kármán constant has its conventional symbol.
4.    It is unclear how Equation 2 and Equation 3 are applied.
5.    Equation 11 has only been calibrated with the author's own experimental data. Is it possible to have measured data or measured data from other PSPSs?
6.    There is also a precondition for Equation 11, that is, the sediment inflow at the inlet is sufficient (calculated according to the Sediment transport capacity formula); for rivers with low sediment concentration, Equation 11 may not be applicable.
7.    The innovation of the article is low. By changing the topography of a reservoir and the range of sediment particle sizes and conducting similar experiments, it is highly likely that completely different formulas can be constructed. Essentially, this article is an engineering report. To explore its innovation, it should be compared with other PSPSs.
8.    The results of the article are purely based on data fitting (although there is also some dimensional analysis); in fact, the change in sediment concentration is controlled by the convection-diffusion equation. The theoretical analysis in the article is superficial.
9.    Numerical modeling is a good way of studying the mentioned problem. Please comment on this. references on hydro-sediment-morphodynamic models are missing.

Author Response

Thank you for your comments. Please see the attached document for details.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The present work is concerned with the the sediment transport characteristics in the lower reservoir area of a specific pumped storage power stations by constructing a physical model and employing multivariate statistical analysis methods. A TSC prediction formula is derived and validated based on sediment-carrying capacity theory. Results reveal that with reservoir length the decay rate of sediment concentration along the path from the reservoir inlet to the power station’s intake and outlet decreases under high inflow conditions. For this, the constructed linear regression model has an acceptable value. The interaction between turbine sediment concentration and hydraulic parameters of the river-type lower reservoir is clarified.

The work seems to be publishable in MDPI: Water if a careful major attention is given to the following comments;

A)- Abstract is designed well.

B)- Language is good overall; take care of local typos deficiencies, punctuation, commas, etc.

C)- The literature survey is fully linked to the studied topic with 41 past and recent efforts.

D)- Expand Model Layout Diagram in figure 1 for clarity in understanding.

E) – Lingyunkou Valley, a tributary of the Hun River. Which country?

F)- Lower sediment concentrations in Eq.(1) and higher sediment concentrations in Eq.(2) should have consistent units.

G) – Fitted Relationship between the Height Difference at Inlet and Outlet Gates and Turbine Sediment Concentration in figure 10 looks fine. How can you make a much better fit?

H) – Join the data in figure 6.

K)- The linear regression model constructed using the inflow sediment concentration, inflow discharge, and the elevation difference between the inlet/outlet and the nearby riverbed has an R² value of 0.8, indicating that these three factors can explain 80% of the variation in the sediment concentration at the turbine for pumped storage power stations. Nonlinear regression models may provide better fits. Other fittings can also be informed like DOI: 10.1108/HFF-01-2018-0003.

L) – The formula for calculating the sediment concentration in the hydro-turbine, fitted based on the influencing factors and given by (11) is successful. However, it is unclear how the exponents are determined.

M) - Future perspectives can be added to the Conclusions section.

Author Response

Thank you for your comments. Please see the attached document for details.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

thanks for the revision.