Optimization of Cascade Small Hydropower Station Operation in the Jianhe River Basin Using a One-Dimensional Hydrodynamic Model
Round 1
Reviewer 1 Report
The paper discusses Optimization of Cascade Small Hydropower Station. It is an interesting topic and the introduction implied the paper considers the ecological impacts which is interesting. Nevertheless, the literature review does not give any information of “what ecological effects are expected?”. The reader should have a clarification at the beginning otherwise they will carry this all the way to the end.
I recommend at the very least elaborating on some of the ecological impacts, in a paragraph or two, and being more specific. You can talk about the effect of hydropower on fish and use the following useful references:
Knott, J., Mueller, M., Pander, J., & Geist, J. (2023). Bigger than expected: Species-and size-specific passage of fish through hydropower screens. Ecological Engineering, 188, 106883.
Mohammadi, M., Mohammadi, A. R., & Mohammadi, M. R. (2014). Optimizing Hydro Power Turbines in Order to Secure the Passage of Fishes in Khuzestan Province. Journal of Applied and Computational Mechanics, 1(2), 95-102. doi: 10.22055/jacm.2014.10755
I can see some explanation in section 3.3 which can be moved to the literature review and better explained with the hints I provided to help. Please do not leave the material vague at the beginning and leave things to the end to explain
The end of the introduction should be a shining part telling the reader what are the aim and objectives. Nevertheless, the current format is too vague. Please clarify your aim and objectives here. Moreover, it is useful to let the reader know what is coming next, section 2 discusses … section 3 discusses…
What is the novelty of your paper? Is this something you do for the first time, or is it something done before? Is the novelty only in the location or in the method used or what?
The sections before 3.2, are useful, the methodology is explained and validation and verification are presented. It seems from section 3.2, the readers should have exciting results. Nevertheless, the results look very limited. Why the fonts are red and blue in some cases? Figure 8 looks very unprofessional, a copy and paste from somewhere, no appropriate legend, or axis title or appropriate font. All the contribution is in Figure 9 which has a low quality and looks very limited novelty.
I would like to give the authors a chance to revise the paper, provide some more interesting results and show the novelty of the work and how this can contribute to the field. At the moment, the paper gives me a feeling that the authors just used the outputs of software regardless of the novelty and the results are very limited with no significant contribution.
no comments
Author Response
Response to Reviewer 1 Comments
Point 1: I recommend at the very least elaborating on some of the ecological impacts, in a paragraph or two, and being more specific. You can talk about the effect of hydropower on fish and use the following useful references:
Knott, J., Mueller, M., Pander, J., & Geist, J. (2023). Bigger than expected: Species-and size-specific passage of fish through hydropower screens. Ecological Engineering, 188, 106883.
Mohammadi, M., Mohammadi, A. R., & Mohammadi, M. R. (2014). Optimizing Hydro Power Turbines in Order to Secure the Passage of Fishes in Khuzestan Province. Journal of Applied and Computational Mechanics, 1(2), 95-102. doi: 10.22055/jacm.2014.10755
Response 1: Thanks for your valuable and thoughtful comments. We have thoroughly reviewed the references suggested by the reviewers and have provided a detailed explanation of the ecological impacts associated with the construction of hydropower stations in the introduction section. The main contents are as follows.
“The construction of a hydropower station alters the natural hydrological rhythm of the river, leading to changes in the river's hydrological regime, water environment, sediment, and other habitat factors. These changes have an impact on the survival and development of organisms in the river ecosystem, particularly fish [10]. Cascade hydro-power development directly affects rivers by disrupting their longitudinal connectivity, cutting off migration channels for migratory fish, fragmenting fish habitats, and ultimately reducing the diversity of aquatic species [11]. Additionally, there is an unavoidable risk of injury and death for fish as they pass through the turbine [12]”
Point 2: I can see some explanation in section 3.3 which can be moved to the literature review and better explained with the hints I provided to help. Please do not leave the material vague at the beginning and leave things to the end to explain
Response 2: Thanks for the reviewer’s suggestion. We have made adjustments to the content of section 3.3 and transferred some theoretical explanations to the literature review section.
Point 3: The end of the introduction should be a shining part telling the reader what are the aim and objectives. Nevertheless, the current format is too vague. Please clarify your aim and objectives here. Moreover, it is useful to let the reader know what is coming next, section 2 discusses … section 3 discusses…
Response 3: Thanks for the reviewer’s suggestion. We have adapted the concluding part of the introduction to further account for the research objectives and have modified the structure of the presentation. The modifications are shown below.
“This study aims to develop a hydrological and hydrodynamic model in order to comprehend the characteristics of water level evolution in small and medium-sized rivers with hydropower stations during various periods. It also aims to identify the crucial areas and research periods for hydropower stations and provide guidance for implementing water ecological protection measures in rivers. In light of these considerations, this study focuses on the research of 17 small cascade hydropower stations in the Jianhe River basin. The first part of the study involves constructing a one-dimensional hydrodynamic model using the MIKE 11HD software. The model is calibrated and verified using data from the study area. In the second part, the constructed model is used to determine the water level evolution characteristics of the main stream of the Jianhe River. Additionally, key operation areas and research periods of the hydropower stations are identified. The final part involves calculating the minimum ecological water requirement of the key research area and proposing an ecological dispatching scheme for the cascade hydropower stations in the Jianhe River basin. The aim of this study is to provide scientific reference for the operation and dispatching of the reservoir.”
Point 4: What is the novelty of your paper? Is this something you do for the first time, or is it something done before? Is the novelty only in the location or in the method used or what?
Response 4: Thanks for your careful work. This study is unique in its focus on small and medium-sized rivers in the study area, which have received little attention in current research. The Jianhe River, located in a mountainous region, is one such river. Due to the high density of hydropower stations, the river's connectivity has been compromised, resulting in the loss of ecological functions, depletion of fish resources, and a significant decline in aquatic biodiversity in the dehydrated and cut-off stretches. To address this issue, a hydrodynamic model is employed to analyze the water level evolution of the Jianhe River, identify key areas and research periods for hydropower station operation, and provide scientific guidance for reservoir operation that balances ecological conservation and power generation.
Point 5: The sections before 3.2, are useful, the methodology is explained and validation and verification are presented. It seems from section 3.2, the readers should have exciting results. Nevertheless, the results look very limited. Why the fonts are red and blue in some cases? Figure 8 looks very unprofessional, a copy and paste from somewhere, no appropriate legend, or axis title or appropriate font. All the contribution is in Figure 9 which has a low quality and looks very limited novelty.
Response: Thanks for your valuable and thoughtful comments. In order to better illustrate the experimental results, Figure 8 has been modified. The potential flow characteristics during the water supply period can be categorized into three sections: A, B, and C. Sections A and C exhibit relatively stable flow patterns overall, whereas section B demonstrates more complex and variable changes in both flow and water level.
The results obtained in Figure 9 are primarily utilized to analyze the variations in water levels during different time periods in regions susceptible to stream interruptions. This information aids in identifying the crucial timeframe for water scheduling in cascade hydropower stations.
In addition, in the final stage of determining the ecological flow, we employ a relatively straightforward empirical method. This method ensures the ecological flow while also determining the power generation of the cascade power station. We are grateful for the valuable suggestions provided by the reviewers. In our future work, we will focus on determining the ecological flow in a more scientific manner. This will enable us to provide a solid scientific foundation and decision-making support for the collaborative operation of cascade small hydropower stations, considering the environmental protection of small and medium-sized rivers.
Figure 8. Analysis of water level evolution characteristics (1#-16# refers to the name of the hydropower station)
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Authors,
In order to protect the ecological system of the water, this manuscript has made the reasonable effort. However, some of the suggestions I am making in order to improve the manuscript’s quality as followed:
1. In the abstract, the results were presented. However, what is the impact on the ecological system the results are suggesting was not presented.
2. In Material and Methods section, the section 2.1 has not got any references. Please provide references where necessary.
3. In the Material and Method section, I think the comprehensive presentation of model’s framework should be provided in order to grasp the modeling flow to obtain the results.
4. What is NAM Model? It appeared all of the sudden in section 2.2.1. Please provide its core definition and its purpose in this section.
5. In the conclusion section, the discussion was based in terps of points. This does not seem appropriate. These results should be written in continuous paragraph format.
6. The recommendations are missing. The conclusion section must include the recommendations based on what results are suggesting what possibly can be done for future context. Second, recommendations must be provided for model improvements, as model must have some limitations, for the researchers to use them for optimizing the model.
7. Some type errors were found, review and correct them.
English is fine. No major mistakes were found.
Author Response
Response to Reviewer 2 Comments
Point 1: In the abstract, the results were presented. However, what is the impact on the ecological system the results are suggesting was not presented.
Response 1: Thanks for the reviewer’s suggestion. The operation of a small hydropower station regulates the volume of river water and alters the hydrological process of the river. When the dam obstructs or diverts a portion of the water to generate electricity, the flow downstream will decrease, and in some cases, it may even be interrupted. If the appropriate dispatching scheme is not implemented in areas prone to flow interruption during critical periods, it can have a negative impact on the ecological environment.
We have updated this in the abstract section of the manuscript.
Point 2: In Material and Methods section, the section 2.1 has not got any references. Please provide references where necessary
Response 2: Thanks for your careful work. The data in the section 2.1 of the manuscript mainly come from the Baise Statistical Yearbook, which is a large reference book that records the annual hydrological, cultural, and other aspects of a place.
We have supplemented the sources of the main data in the section 2.1 of the manuscript.
Point 3: In the Material and Method section, I think the comprehensive presentation of model’s framework should be provided in order to grasp the modeling flow to obtain the results.
Response 3: Thanks for your valuable and thoughtful comments. The general structure of the model contains three interrelated storages, categorized as overland flow, interflow, and base flow, as shown in Figure 2.
We have added this part to the Materials and Methods section of the manuscript.
Figure 2. MIKE NAM model structure
Point 4: What is NAM Model? It appeared all of the sudden in section 2.2.1. Please provide its core definition and its purpose in this section.
Response 4 : Thanks for your careful work. Rainfall-runoff model (MIKE NAM) is part of MIKE 11 model used by many researchers worldwide. It is a deterministic, lumped conceptual rainfall-runoff model, which is originally developed by the Technical University of Denmark (Journal of Environmental Management. 2012, 94, 132-143).
We have updated the NAM model introduction and MIKE NAM model structure in section 2.2.1 of the manuscript.
Point 5: . In the conclusion section, the discussion was based in terps of points. This does not seem appropriate. These results should be written in continuous paragraph format.
Response 5: Thanks for the reviewer’s suggestion. We have adjusted the expression of the conclusion section.
Point 6: The recommendations are missing. The conclusion section must include the recommendations based on what results are suggesting what possibly can be done for future context. Second, recommendations must be provided for model improvements, as model must have some limitations, for the researchers to use them for optimizing the model.
Response 6: Thanks for the reviewer’s suggestion. Based on the experimental results, we have included some suggestions in the conclusion as follows.
“To prevent the construction of a hydropower station from causing significant damage to the ecological environment of the river, it is crucial to establish a joint water transfer management organization in the river basin. This organization should establish a scientific and reasonable joint operation system and conduct scientific operations in areas with a high risk of flow interruption during critical periods. Additionally, when it comes to model parameter calibration, relying solely on computer automatic calibration methods has limitations. It is important to leverage human knowledge and experience and combine it with computer automatic optimization algorithms.”
Point 7: Some type errors were found, review and correct them.
Response 7: Thanks for your careful work. We have revised the whole manuscript carefully and tried to avoid any grammar or syntax errors.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Thank you for addressing my concerns, I have no further comments.
some proof readings might be required
Reviewer 2 Report
Yes, Authors have made the suggested changes.
Minor English corrections are required.
