Field Experimental Assessment of HYDRUS-3D Soil Moisture Simulations Under Drip Irrigation Using Horizontal Mobile Dielectric Sensor

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The study presents interesting and important findings on the performance of HYDRUS-3D compared to soil moisture sensors in a drip irrigation setting. The results were positive and showed good correlation between model and sensor measurements, adding important validation of the utility of the model for guiding drip irrigation applications.

 

The materials and methods section did not capture the statistical analysis methods used in the study to compare field and simulated data. For example, RMSE only appeared in the results and discussion.

 

Line 87: It was not clear in the materials and methods section how authors maintained consistent soil bulk density (BD) or why it was important to try to maintain constant BD.

 

The results were not robustly discussed. This is understandable because it is a short communication and the word count is restricted, but please ensure that the most important details are presented and discussed.

 

Line 273: part of the conclusion read, “HYDRUS-3D has been proved its accuracy in modeling real-time soil moisture changes, outperforming HYDRUS-2D in precision.” Aside the fact that the sentence could be better rephrased, I am not sure this is an appropriate conclusion since the research did not directly compare both HYDRUS-2D and HYDRUS-3D. Conclusions should be drawn strictly from the study’s results to avoid overstatements.

 

 

Comments on the Quality of English Language

There were many minor grammatical issues, typos, or sentences that need to be rephrased for clarity throughout the paper. Below are a few examples. Please carefully review all text.

Line 48: HYDRUS-3D is widely used and powerful packages for modeling variably saturated…

Line 117: …within drip irrigation farmland in the actual agricultural production process.

Line 220: …with slop steepness…

Author Response

Comments 1: The materials and methods section did not capture the statistical analysis methods used in the study to compare field and simulated data. For example, RMSE only appeared in the results and discussion.

Response 1: Thank you for pointing this out. In the revised version, we added ‘2.5 Statistical analysis’ (Lines 202-210).

 

Comments 2: Line 87: It was not clear in the materials and methods section how authors maintained consistent soil bulk density (BD) or why it was important to try to maintain constant BD.

Response 2: Agree. We added descriptions regarding the importance of bulk density and its control methods in the "Materials and Methods" section (Lines 106-115).

 

Comments 3: The results were not robustly discussed. This is understandable because it is a short communication and the word count is restricted, but please ensure that the most important details are presented and discussed.

Response 3: Agree. We added descriptions and discussions of some important results in the "Results and Discussion" section (Lines 222-224, 229-231, 233-235, 268-270, 313-319, 323-327).

 

Comments 4: Line 273: part of the conclusion read, “HYDRUS-3D has been proved its accuracy in modeling real-time soil moisture changes, outperforming HYDRUS-2D in precision.” Aside the fact that the sentence could be better rephrased, I am not sure this is an appropriate conclusion since the research did not directly compare both HYDRUS-2D and HYDRUS-3D. Conclusions should be drawn strictly from the study’s results to avoid overstatements.

Response 4: Agree. We removed this conclusion and revised the relevant content within the discussion section (Lines 323-327).

 

Comments on the Quality of English Language

Comments 5: There were many minor grammatical issues, typos, or sentences that need to be rephrased for clarity throughout the paper. Below are a few examples. Please carefully review all text.

Response 5: Thank you for pointing this out. We have asked native English speakers to polish the English in our article. All the revisions have been marked in red.

 

Comments 6: Line 48: HYDRUS-3D is widely used and powerful packages for modeling variably saturated…

Response 6: Accepted and improved. We added “a” and replaced the “packages” with the “tool” in this sentence (line 49).

 

Comments 7: Line 117: …within drip irrigation farmland in the actual agricultural production process.

Response 7: Accepted and improved. We rewrote this sentence (line 156).

 

Comments 8: Line 220: …with slop steepness…

Response 8: Accepted and improved. We corrected the word "slope" (line 277).

Reviewer 2 Report

Comments and Suggestions for Authors

The article is entitled ‘Field experimental assessment of HYDRUS-3D soil moisture simulations under drip irrigation using horizontal mobile dielectric sensor’.

The aim of this study was to investigate the three-dimensional water infiltration of drip irrigation using HMSS in innovative field experiments and to evaluate the ability of Hydrus-3D to simulate three-dimensional water infiltration based on the results of field experiments. The problem addressed is relevant to irrigated agricultural land. The topic is particularly relevant for arid and semi-arid areas where water resources are scarce and metering water in the right amount is important.

My comments are as follows:

- The abstract needs improvement, it should include the aim of the work, methods and main conclusions

- The introduction needs to be completed, especially for new literature published after 2020.

- description of the methods used in the paper needs improvement. The authors should provide a scheme/diagram of the sequence of steps so that the experiment can be repeated. A shortcoming of the paper is also the small test area on which the experiment was conducted. The authors should indicate to what extent it is possible to apply the present irrigation system for large irrigated areas. What are the limitations of the solution used?

- The results and discussion are well guided, supported by the literature

- Conclusions need to be supplemented. Identify the advantages and disadvantages of the proposed solution

- Tables and figures need improvement, they should be formatted according to the requirements of the journal (appropriate style).

Comments on the Quality of English Language

I do not feel entitled to assess the correctness of the English language

Author Response

Comments 1: The abstract needs improvement, it should include the aim of the work, methods and main conclusions

Response 1: Thank you for pointing this out. We rewrote the abstract (Lines 13-28).

 

Comments 2: The introduction needs to be completed, especially for new literature published after 2020.

Response 2: Accepted and improved. We have cited the latest research on HYDRUS-3D and conducted an analysis, further demonstrating the distinctiveness of our work (Lines 50-61). 

 

Comments 3: description of the methods used in the paper needs improvement. The authors should provide a scheme/diagram of the sequence of steps so that the experiment can be repeated. A shortcoming of the paper is also the small test area on which the experiment was conducted. The authors should indicate to what extent it is possible to apply the present irrigation system for large irrigated areas. What are the limitations of the solution used?

Response 3: Accepted and improved. In the revised version, we have added Figure 1 to illustrate the processes of the field experiment and the HYDRUS-3D simulation. Moreover, we have included an explanation regarding the application scale expansion and limitations of the HMSS in the "Materials and Methods" section (Lines 135-143).

  

Comments 4: The results and discussion are well guided, supported by the literature

Response 4: Thanks for your comments.

 

Comments 5: Conclusions need to be supplemented. Identify the advantages and disadvantages of the proposed solution

Response 5: Accepted and improved. We rewrote the conclusion and added a discussion on the advantages and limitations of this study (Lines 338-344).

 

Comments 6: Tables and figures need improvement, they should be formatted according to the requirements of the journal (appropriate style).

Response 6: Accepted and improved. We made revisions to the figures and a table following the requirements of the "Instructions for Authors" (see figures and a table in the revised version).

Reviewer 3 Report

Comments and Suggestions for Authors

The study, titled “Field experimental assessment of HYDRUS-3D soil moisture simulations under drip irrigation using horizontal mobile dielectric sensor,” evaluates the performance of the HYDRUS-3D model in simulating soil moisture under drip irrigation, incorporating horizontal mobile sensors for field validation.

Suggested Improvements

Abstract:

1. The abstract is informative but could be more concise. Instead of listing numerical values, briefly interpret their significance.
2. Strengthen the conclusion by emphasizing how this study advances HYDRUS-3D field validation.

Introduction:

2. Provide more context on previous limitations of soil moisture detection methods and why HMSS is a valuable alternative.
3. Clarify how this study specifically builds upon or fills gaps in prior HYDRUS-3D validation efforts.
4. The objectives should be more explicitly stated. Consider using bullet points or a clearer structure for clarity.

Materials and Methods:

5. The setup description is thorough, but a clearer distinction between the central and slope areas in the trapezoidal configuration would improve understanding.
6. Further explain how HMSS calibration ensures measurement accuracy, especially compared to traditional methods.

Results and discussion:

7. Figures should be explicitly referenced in the text with clear explanations of what each visual represents.
8. Expand the discussion of prediction errors to account for field-scale variability and potential improvements in modeling accuracy.

Conclusions:

9. Summarize key numerical findings in simpler terms for broader impact.
10. Discuss the broader applicability of HMSS and HYDRUS-3D in various irrigation contexts.
11. Include a brief statement on study limitations (e.g., soil type constraints, time-scale considerations) and suggest future improvements.

Author Response

Abstract:

Comments 1: The abstract is informative but could be more concise. Instead of listing numerical values, briefly interpret their significance.

Response 1: Thank you for pointing this out. We have rewritten the abstract. Instead of simply listing numerical values as in the original, we have now focused on presenting the significance of the results (Lines 22-24).

 

Comments 2: Strengthen the conclusion by emphasizing how this study advances HYDRUS-3D field validation.

Response 2: Accepted and improved. We added content regarding "emphasizing the promotion of field validation of HYDRUS-3D" in the abstract (Lines 24-28).

 

Introduction:

Comments 3: Provide more context on previous limitations of soil moisture detection methods and why HMSS is a valuable alternative.

Response 3: Accepted and improved. In the introduction, we added a discussion on the latest soil moisture detection methods used in HYDRUS-3D research and explained the differences and advantages of the HMSS adopted in this study (Lines 50-61, 69-74).

 

Comments 4: Clarify how this study specifically builds upon or fills gaps in prior HYDRUS-3D validation efforts.

Response 4: Accepted and improved. We clarified the differences and advantages in data acquisition between HMSS and other soil moisture detection methods and described the potential to fill the gaps in HYDRUS-3D validation (Lines 50-61, 69-74).

 

Comments 5: The objectives should be more explicitly stated. Consider using bullet points or a clearer structure for clarity.

Response 5: Accepted and improved. We revised the objectives in the introduction (Lines 75-79).

 

Materials and Methods:

Comments 6: The setup description is thorough, but a clearer distinction between the central and slope areas in the trapezoidal configuration would improve understanding.

Response 6: Thank you for pointing this out. In Figure 2a, we added the annotations for the "central cuboid areas" and “sloped areas.

 

Comments 7: Further explain how HMSS calibration ensures measurement accuracy, especially compared to traditional methods.

Response 7: Accepted and improved. We added the detailed process of sensor calibration (Lines 144-153).

 

Results and discussion:

Comments 8: Figures should be explicitly referenced in the text with clear explanations of what each visual represents.

Response 8: Accepted and improved. We added descriptions and discussions regarding the figures (Lines 222-224, 229-231, 233-235, 268-270).

 

Comments 9: Expand the discussion of prediction errors to account for field-scale variability and potential improvements in modeling accuracy.

Response 9: Accepted and improved. We added a discussion on prediction errors (313-319).

 

Conclusions:

Comments 10: Summarize key numerical findings in simpler terms for broader impact.

Comments 11: Discuss the broader applicability of HMSS and HYDRUS-3D in various irrigation contexts.

Comments 12: Include a brief statement on study limitations (e.g., soil type constraints, time-scale considerations) and suggest future improvements.

Response 10-12: Thank you for pointing these out. We rewrote the conclusion, incorporating the above-mentioned suggestions (Lines 332-344).

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for your responses.