Siltation of Small Water Reservoir under Climate Change: A Case Study from Forested Mountain Landscape of Western Carpathians, Slovakia
Round 1
Reviewer 1 Report
The authors address an important question, does forest regrowth offset the potential effects of climate change, such as an increase in erosive, high intensity storm event?. They used reservoir sedimentation data for two time intervals in the same watershed to investigate this question.
Their conclusions are that reforestation has offset the contributions that could arise from increases in storm intensity. Furthermore, much of the current soil loss is from forest roads, which suggests that maintenance may mitigate this source in the future.
The main question is: Are the author's conclusions supported by their data?
Issues:
1. No data on changes in storm intensity between the 2 time periods is presented. They show that mean annual precipitation has increased between the two time periods, but they do not indicate the standard deviation of precipitation in each of these 2 time periods. Values of R in the USLE estimated from annual precipitation changes are presented in the results and these indicate an increase in values.
2. No error analysis is conducted for the measurement of sediment volumes and sediment yield. Sources of error on sediment volumes include measurement error (1 cm minimum, giving a 2% error at minimum), measurement intervals, use of the reservoir plans for the 1989 configuration of post-dredging depths. Adding the error analysis will bolster, not reduce the argument, that annual sedimentation has stayed approximately constant for the 2 time periods.
3. No error analysis is conducted for the sediment yield results. Sources of error on sediment yield include: a) sediment volume error, trap efficiency error (for which they have upper and lower bound estimates from multiple methods) and variations in bulk density. Bulk density was measured at 10 locations, but we are given no indication of whether it varies along the length of the reservoir or with depth in the reservoir (grain size might increase towards the top of the deposits if the trap efficiency is significantly reduced). All of these sources of error can be quantified or estimated and used in an error propagation equation for the sediment yield calculations.
3b. Errors in the
4. It is not clear what is mapped in fig. 2. No legend is provided that shows the units or derivation of the erosion potential. Is this soil erodibility or erosion sources--this is not clear from either the map or the text.
5. Maps need scale bars and legends.
6. I think you could combine several of the tables.
7. Minor changes in word usage are needed (be careful with plurals, etc.).
Adding error analysis would increase the reliability of the results, but would not likely modify the results. This is an interesting and timely paper that I would like to see published.
Author Response
The replies are provided in (attached) Word file.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Small reservoirs are important for regulating the hydrological condition in the watershed. The effectiveness of small reservoirs in a mountain landscape always decreases over time due to the gradual siltation. This research obtains some interesting conclusions and is able to study the situation in the research site. However, the structure of the article needs to be optimized and the international significance of the study needs to be expanded. The detailed comments are as follows.
1. L47 Add citation.
2. L50-53 Add citation
3. L48-56 Merged with the first paragraph
4. L72-80 This paragraph should be joined with the first paragraph if it presents a global overview, or with the previous paragraph if it presents the study area.
5. L99-101 As WATER is an international journal, the international significance of this article needs to be expanded.
6. L117 The landscape contains not only vegetation.
7. L139 USLE/RUSLE model was developed on clear-cut plots. Was it calibrated or validated when used for the calculation of soil erosion in the watershed of the study area of this paper?
8. L395 The presentation of the methods and formulas and the basic data should be described in the second part and should not appear in the results.
9. L418 Results should be derived from this study and should not show citations.
10. L428 “R” should be in italics.
11. L649 There is no twist here. Delete “However”.
12. L523 The relationship between the discussion section and the results section is not clear.
13. The citation of the last three years of literature is not sufficient.
Author Response
Replies are provided in the attached Word file.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
The authors responded to most of the revisions. I still stand by my opinion on the comments about the structure of the article. Therefore, let the editor make the final decision.
Author Response
The demanded changes of article structure were done. We moved all preliminary calculations supporting the methodological approaches from Results to Methods. Thank you for your (repeated) suggestion; we hope the article is more readable now (as you expected).
