Research on the Comprehensive Optimization of the Hydraulic Performance and Frost-Heaving Resistance of a Parabolic Channel
Round 1
Reviewer 1 Report
The manuscript addresses the simultaneous optimization of an open channel with a parabolic cross-section respect to 1) the hydraulic performance and 2) the resistance to frost-heaving. The former is measured through the width-to-depth ratio, whereas the latter is parametrized in terms of amplitude of the range of bending moments acting on the cross section lining. The multi-objective problem is approached based on the alpha-method of the linear weighted sum method. An application of the method is provided with reference to the Shijin Irrigation District. The benefits of the optimized cross section shape compared with the actual one are demonstrated considering several aspects, as hydraulic performance, force uniformity and land-use.
The manuscript addresses an original and relevant topic, and it well suits the scope of the journal to which it has been submitted. The problem is rather clearly stated, even though the manuscript could be improved on this point. The methodology is well explained, but at some points the underlying assumptions should be better discussed. Language and editing deserve further dedication. Overall, I am supportive about the publication of the manuscript provided that the Authors prepare a revised version addressing the issues listed above:
- General remark 1: which is the effect of the uncertainty of the value the input parameters on the evaluation of the optimal solution? I wonder if it makes sense, on the practical point of view, to adopt a comprehensive optimal cross section shape if the values of the input parameters (for instance, the soil properties) cannot be determined with a sufficient degree of reliability? How does this uncertainty reflect on the practical value of the proposed method? I think that the Authors could discuss the point (maybe including some evaluation even in the example application) to improve the value of their results and of their manuscript.
- General remark 2: the Authors should better discuss the pros and cons of the optimization method they adopted. Did they make any comparison with other alternative methods? Do they expect that this may change significantly the comprehensive optimal solutions? I would appreciate that the revised version of the manuscript contains some comments on these points.
- Introduction: please avoid non-standard terms (for instance: “arc foot trapezoid”, “arc bottom trapezoid”).
- Line 45: please reword, base soil expansion is not due to “negative temperatures”, but to “icing of soil water”
- Lines 53-55: here the advantage of parabolic section is described. To what shape are you comparing the parabolic one?
- Please describe in a more detailed manner which are the actions induced y frost-heaving on the cross-section lining, and how these may produce damages to the channel. Please provide examples of regions where frost-heaving may occur.
- Line 104: please explain better why the increase of the width-depth ratio implies smaller frost-heaving forces.
- Line 119-114: Please shorten these sentences
- Line 118-119: are these lines part of the caption or of the text?
- Line 147-148: please avoid past verbs. Additionally, please explain why slow flow implies an increase of the load of the channel
- Line 154: please avoid past verbs
- (6): please provide an explanation of the formula given here: readers should be made aware of the underlying hypotheses and of the origin of this expression.
- Line 168: “take safety into consideration” should read “conservatively” or “to be on the safe side” or similar standard sentences.
- Please check that symbols in the text are always written in italic
- Line 198: “reversible” should read “invertible”
- (14): LHS should be alpha?
- Line 243: “Rectangular” should read “Cartesian”
- (20): please check
- Line 252: c is a repeated symbol for two distinct parameters (here the channel half opening, later a coefficient related to soil texture). Please avoid this duplication.
- Line 258: please check the use of “factored” here
- (25) Symbol at LHS not readable in my file
- (26) Symbol at LHS not readable in my file
- (28) Symbols not readable in my file
- Line 277: why is it needed eq. (30) here?
- Line 304: delete “when”
- Table 1: please improve readability and line breaking
- Table 2: please improve readability and line breaking
- Line 337: I suggest adding a line break at “The comprehensive….”
- References: please check carefully the style requirements and the consistency of the citations
- Please carefully review English
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript presents a theoretical analysis on how to include frost-heaving considerations when optimizing channel cross-sections of parabolic type. The topic has both theoretical and practical interest. The paper is well organized and written.
Specific comments and typos:
- A list of symbols would help the reader to go through the equations.
- Line 118: two text lines have been apparently inserted into the image of Figure 2 (between Figure and caption).
- Line 163: equation (6) is not consistent with the variables and units defined in lines 163-164.
- Equation (16). Please, enlarge parentheses symbols up to the vertical size of the terms within parentheses. The same in Equations (18), (19) … Also, consider combining parentheses and brackets in Equations (18), (19) …
- Figure 5: it is not clear what is the meaning of the label that starts with a square root symbol. Please, improve the figure.
- Equations (25)-(28): Chinese subscripts should be replaced by appropriate Latin characters or Greek symbols.
- Equation (28) has been truncated (last terms are missing).
- Equation (31) is the identical to Equation (2), so it is not worth including it.
- Tables 1 and 2: use adequate widths for each column so that numbers or words do not split into two lines.
- References: indicate if references are in Chinese where appropriate.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The Authors have accounted for all the requested issues. In my opinion, the manuscript is ready for publication after minor editorial fixes and final proofreading. Mainly, the references section deserves some further detail to be fixed: for instance, ref. # 5 family names are abbreviated.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
