Infiltration and Failure Behavior of an Unsaturated Soil Slope under Artificial Rainfall Model Experiments
Round 1
Reviewer 1 Report
Water-2341473 “Infiltration and Failure Behavior of an Unsaturated Soil Slope under Artificial Rainfall Model Experiments” Shu-Rong Yang and Li-Jie Huang
· What is the significance, if any, of the 60-degree slope in the model soil slope? Is this a common land surface angle of backfilled material? Is this typical of land slopes in regions of Taiwan?
· Figure 2 is not required. Adding another two sentences to the existing 3-lines of text that make up S2.2 would be adequate. The figure is only text in boxes anyway with no branching.
· The last sentence on page 6 lines 172-173 is not well expressed. The previous sentence said that an increase in rainfall rate did not impact infiltration behaviour as most rainfall became runoff, therefore unless the soil is sealing due to rainfall impact energy, any rainfall rate greater than the saturated hydraulic conductivity is unlikely to change infiltration behaviour. As this value is not presented, nor any structural changes in the soil during the experiments, it is difficult to evaluate the statement.
· The paragraph on page 7 lines 177-186 discusses “gully initiation” as slope failure while the first line of the Abstract describes “shallow landslides”. Are both conditions considered slope failure? Does gully initiation indicate the likelihood of shallow landslides? If the title were “Slope Failure Behaviour of an Unsaturated Soil Slope under Artificial Rainfall Conditions” then you could define what types of behaviour can be considered slope failure within the article.
· The caption of Figures 8 and 14 should tell the reader what direction they are viewing the model soil slope from, and use arrows to indicate the significant items in each panel.
· Conclusion #3 is too general, and the last phrase should be “indicating that once significant runoff was initiated increasing the rainfall intensity had minimal effect …”
· Conclusion #5 is unclear to me. If it takes much longer to infiltrate water at high compaction at a fixed rainfall rate, then more runoff must be generated with higher compaction. Conclusion #7 says that more runoff results in more severe scour, yet #5 says higher compaction results in a decrease in severity of slope failure. Can the authors reconcile or combine these two conclusions into a coherent statement(s).
Author Response
Please find the attached file for your reference.
Author Response File: 
Author Response.docx
Reviewer 2 Report
I have carefully read the manuscript water-2341473-v1 entitled “Infiltration and Failure Behavior of an Unsaturated Soil Slope under Artificial Rainfall Model Experiments”. The paper is investigating the effects of rainfall intensity, initial moisture content, and relative compaction on infiltration and failure behavior of an unsaturated soil slope subjected to rainfall infiltration. For this purpose, the artificial rainfall was applied to a compacted soil slope in laboratory. The moisture content was monitored during the experiment using soil moisture probes installed in soil slope. Several results were presented and thoroughly discussed. The manuscript is scientifically sound, well written and presented, and adding to the bulk knowledge. The title and abstract are short and representative. The introduction/literature review is relevant and up-to-date. The methodology and procedures are clearly presented. The results were thoroughly discussed. I have few suggestions:
1. The experiment flow chart (Figure 2) can be re-designed in another format using flow chart templates. Additionally, you can use (few representative words) in each step instead of using (long sentences). Moreover, would you please be consistent and use the same (font size and type) that used in the other figures (such as Figures 4 and 5)?
2. Would you please check L112: “± 2%”?
3. Thanks to the authors for citing some references while discussing the results in the (Results and Discussion section). I suggest citing more references in this section.
4. The soil saturation contours (i.e., Figures 6, 7, 9, 10, 12, and 13) have very small font size and poor resolution. I suggest enriching the resolution and/or enlarging those figures.
5. I am also suggesting use (conclusions #8 and 9) as a summary paragraph for the (Conclusions section) not as points in the conclusions’ list.
Author Response
Please find the attached file for your reference.
Author Response File: Author Response.docx
Reviewer 3 Report
The manuscript studies the Infiltration and Failure Behavior of an Unsaturated Soil Slope under Artificial Rainfall Model Experiments. The subject is interesting, however, some comments need to be done before accepting the paper for publication.
- Results in the abstract did not show any values or numbers. I suggest paraphrasing the abstract and providing some figures/numbers.
- Introduction needs to be improved by adding the most recent studies on the same topic.
- Calculating the coefficient of uniformity and coefficient of curvature is mandatory in sieve analysis and soil classification.
- Section 2.2 I suggest changing the flow chart to text.
- Line 112 check the format.
Author Response
Please find the attached file for your reference.
Author Response File: Author Response.docx
