The Role of Frost Processes in the Retreat of River Banks

Round 1

Reviewer 1 Report

• Overall, the work is interesting, although it is not clear what the study's novelty is. What is the step forward? Does the title of your manuscript claim to be a kind of universality of conclusions, or is it a special case and only new data for the Carpathians? Please decide on this. The title of the manuscript seems to me not quite correct also for another reason. It is better to write not about the role of frost processes in erosion but their role in the retreat of river banks.
• The manuscript should be better structured. The "Aim of the paper" section needs to be rewritten to show the study's purpose clearly. Some of the material in this section relates to methodology. Moreover, the content of the section should be part of the "Introduction". The "Materials and methods" should have its own logical internal structure (subsections, including the "Study Area").
• In "Introduction", the authors give examples of riverbank retreat rates in different parts of the world. But most examples do not analyze the role of frost processes in this retreat. In this regard, why are these examples given? How are they directly related to your research? For example, what relation do rivers in the tropical state of Queensland (Australia) have to frost-induced deformations of river banks? What did you want to show using these examples? All rivers deform their bank!
• What is the purpose of Figure 1B?
• All figures should be located logically in the text and linked to the information that they accompany in the text. Figure 1 should be the first so that the reader can have a clear idea of the river basin of your study. The same goes for tables. It is complicated to navigate the manuscript when the figures and the table are in the wrong order.
• The methodological part of the manuscript does not explain why the authors chose these five sites for research but not in some other places. What are the reasons for this choice?
• It would be desirable to have a photographic example of one of the research plots to understand the research methodology better.
• It would be desirable to improve the readability of Figure 6.
• Table 2. In what units are "Amounts of erosion" expressed? What is this characteristic? Erosion rate? The volume of erosion products? This is not clear. Check it out everywhere in the text.
• Table 3. “… evolution of river banks”. This is not evolution but temporal dynamics. Evolution is a more complex concept. Why are there so many % signs? It is enough to specify once after "Share of frost ...".
• The overwhelming majority of research plots were located on concave river banks (within river meanders), where the hydrodynamics of the water flow differs from relatively straight riverbed sections. As a rule, the rate of riverbed deformations on concave banks is higher than outside them. Why is this important issue not discussed in any way in your research? If you were to compare the contribution of frost-induced deformations on river banks' sections with different degrees of curvature of their riverbeds in the same lithological complexes, then the results of your research could be more interesting and scientifically significant. The lack of this analysis is the weak point of your research.
• Józef Kukulak Józef?

Author Response

Thank you very much for review and all sugestion

Comments and Suggestions for Authors

Overall, the work is interesting, although it is not clear what the study's novelty is. What is the step forward? Does the title of your manuscript claim to be a kind of universality of conclusions, or is it a special case and only new data for the Carpathians? Please decide on this. The title of the manuscript seems to me not quite correct also for another reason. It is better to write not about the role of frost processes in erosion but their role in the retreat of river banks. - We changed the title according to the reviewer’s suggestion to “The role of frost processes in the retreat of river banks”

The manuscript should be better structured. The "Aim of the paper" section needs to be rewritten to show the study's purpose clearly. Some of the material in this section relates to methodology. Moreover, the content of the section should be part of the "Introduction". The "Materials and methods" should have its own logical internal structure (subsections, including the "Study Area"). – according to the reviewer’s suggestion we have dropped a fragment of  1. Introduction, dropped the title 2. Materials and Methods, and replaced it with the title 1. Introduction

In "Introduction", the authors give examples of riverbank retreat rates in different parts of the world. But most examples do not analyze the role of frost processes in this retreat. In this regard, why are these examples given? How are they directly related to your research? For example, what relation do rivers in the tropical state of Queensland (Australia) have to frost-induced deformations of river banks? What did you want to show using these examples? All rivers deform their bank!– We have presented here the examples to demonstrate the potential of the method for measuring the rates of various processes and its worldwide use. Erosion pins is also being used to study frost processes on river banks – as by Lawler D.M. (1986, 1987, 1993) who monitored river banks in south Wales, or by Luffman and Nandi (2019) who conduct their studies in the south-east of the USA.

What is the purpose of Figure 1B? – Figure 1B is aimed at easy reading of temperature oscillations around 0°C. This less legible in Fig. 1A.

All figures should be located logically in the text and linked to the information that they accompany in the text. Figure 1 should be the first so that the reader can have a clear idea of the river basin of your study. The same goes for tables. It is complicated to navigate the manuscript when the figures and the table are in the wrong order. – the figures and tables were rearranged according to the suggestion

The methodological part of the manuscript does not explain why the authors chose these five sites for research but not in some other places. What are the reasons for this choice? – We have added explanation in the text. The choice of study sites depended on several factors: accessibility, lack of vegetation, kind of sediment in the bank (pins can not be pushed into non-alluvial banks), proximity of the stations monitoring temperature and river discharge, and the distance of access that allows for rapid reaction in case of extreme events.

It would be desirable to have a photographic example of one of the research plots to understand the research methodology better. – We have added adequate photographs

It would be desirable to improve the readability of Figure 6. – We have tried, but because of the amount of information contained, the sucess is modest.

Table 2. In what units are "Amounts of erosion" expressed? What is this characteristic? Erosion rate? The volume of erosion products? This is not clear. Check it out everywhere in the text. – the amount are given in centimeters. Respective information has been added in the table to make it conformable with the text.

Table 3. “… evolution of river banks”. This is not evolution but temporal dynamics. Evolution is a more complex concept. Why are there so many % signs? It is enough to specify once after "Share of frost ...". – changed according to the suggestion.

The overwhelming majority of research plots were located on concave river banks (within river meanders), where the hydrodynamics of the water flow differs from relatively straight riverbed sections. As a rule, the rate of riverbed deformations on concave banks is higher than outside them. Why is this important issue not discussed in any way in your research? If you were to compare the contribution of frost-induced deformations on river banks' sections with different degrees of curvature of their riverbeds in the same lithological complexes, then the results of your research could be more interesting and scientifically significant. The lack of this analysis is the weak point of your research. – Such analysis would be of course interesting. Our ongoing study is aimed at this goal. We are additionally using laser scanning to compare the results of the two methods.. In this study we did not finding such sections on river banks because the exposed banks differed markedly in the degree of cementation in sediments.

Józef Kukulak Józef? – thanks, corrected.

Reviewer 2 Report

The authors present a nice data set showing the differences between winter and summer bank erosion, and they use these data to infer the relative importance of erosion by frost as compared to fluvial erosion.  The study design provides some unusually clear differences between the two processes, and the results are an interesting contribution to the literature on bank erosion by fluvial and frost processes.

The manuscript needs some attention before it should be published.  My comments mostly involve improving the presentation (writing, some small typographical errors, better annotation of some of the details in figures and tables) and are relatively minor.   I have also suggested some additions to the discussion of materials and methods (how is grain size assessed, for example).  The authors should also address new high resolution methods of remotely mapping riverbanks using terrestrial LiDAR and structure-from-motion photography.  These methods, while somewhat time-consuming, should ultimately replace erosion pins which invariably must interfere with the process being measured in serious ways.

I would also like the authors to provide some assessment of the generality of their results.  They find that fluvial erosion exceeds that of frost by a considerable degree.  Do they expect this result to apply to most banks, or is this only a feature of their study site?  Why or why not?

An additional reference to consider:  Pizzuto, 2009, Geomorphology, in which fluvial processes account for 87% of the total erosion, with frost processes accounting for the remainder.

Overall, I would judge this to be a useful and interesting set of observational data that clearly describe the relative important of frost and fluvial erosion in a single watershed.  The data are unusually clear and therefore interesting.  This is a case study which seems to have local importance without providing much new generally applicable information, but of interest nonetheless to fluvial geomorphologists and others who wish to better understand river bank erosion.

Jim Pizzuto
Department of Earth Sciences
University of Delaware
Newark, DE USA

Some detailed comments:

1.     Introduction - placeholder text from the journal’s template seems to be here, rather than the author’s introduction.
2.    Lines 37-38 - List is anthropogenic effects is somewhat brief - many others to note.
3.    Line 40 - colon does not seem appropriate here.
4.    Paragraph beginning in line 45 - This is an odd review.  Too short and lacks focus.
5.    Line 47 - Lawler is misspelled.
6.    Line 106.  Based on the maps provided and the discussion later in the manuscript, it doesn’t seem as if the study sites were established at straight sections.  This is misleading.
7.    Materials and methods - The reader needs to know more about the river.  Classification?  Gravel or sand-bed?  Riparian vegetation?  Any influence from engineering structures?  Land-use in the watershed (e.g., any urbanization or other anthropogenic land use)? Dams or other structures that would modify the frequency of flows?  Any confinement by bedrock or other non-alluvial substrate?
8.    Lines 141 and 144.  Please note in these figure captions that the metro and stream gauging station locations are indicated in Figure 3.
9.    Line 148.  I wondered here about the spacing of the pins.  Could these details be given here rather than later?  Or at least a note stating that it will be discussed later?
10.    Line 151.  What methods are used to define the grain size characteristics of the bank sediments?  This is important.
11.    Line 153.  I think Wolman's 1959 paper in the American Journal of Science is the first use of erosion pins.  Cite.
12.    Line 161.  If it is important to include more up-to-date methods, then terrestrial lidar and structure-from-motion image analysis should be mentioned.  See, for example, O’Neal and Pizzuto (2010) in Earth Surface Processes and Landforms, for example. Really no use uses PEEPs as far as I know, anyway.
13.    Line 165.  “Integrated” is misspelled.
14.    Line 166.  Sentence is not clear - please revised.
15.    Line 170.  Greater than what? Please clarify.
16.    Line 171.  “Separated individual plots”?  I don’t understand what this means.  Please clarify.
17.    Lines 173-174.  Does this mean that basal erosion was not measured?  Please clarify.
18.    Line 175…..” deep enough to resist for a long time….”  Please clarify what this means.
19.    Lines 185-190.  This listing of dates would be better placed in a table.  It is difficult to follow in the text, and unnecessarily detailed.
20.    Line 193, caption for figure 3.  I think “used” can be deleted.
21.    Line 194.  Subheading “Site 1” is not very descriptive.  What information about Site 1 is provided.
22.    General comment:  The large number of erosion pins must have had some impact on the erosion processes, providing some degree of bank reinforcement, or focusing stream erosion through eddies around the pins and so on.  This should be discussed somewhere.
23.    Line 197.  Why is the alluvial gravel “cemented”?  Is this a deposit of the contemporary river, or is it bedrock?  In my experience, contemporary fluvial gravels are rarely cemented.  Please explain in greater detail.
24.    Line 198 and elsewhere.  The reference to “clay” should be explained and clarified.  In my experience, most fine-grained alluvial deposits are mostly silt, with lesser amounts of clay.  What does the descriptor “clayey” actually mean?  Please reference some standard source for terminology so the reader will understand how much clay is present in these deposits.   Also please explain how the clay was identified.  Was a lab test performed, or is this description based on visual observation in the field?  This is important.
25.    Line 204 - “clay layer”.  See comments above.
26.    Line 204.  “The bank is there”.  Please revise to improve writing.
27.    Line 216.  “Ros”?  Typo?
28.    Line 217.  The separation referred to here is only present at low flow, right?  Please clarify.
29.    Figure 5 - Are these grain size percentages MEASURED or estimated visually in the field?  Please clarify somewhere in METHODS.
30.    Line 245 - “sandy-clayey”.  Please explain or provide a reference for these terms.  Presumably they have precise meanings.
31.    Line 248.  “id” - typo?
32.    Table 1 - is the column “type of alluvium” supposed to summarize the characteristics of the full bank height?  Please clarify.
33.    Figure 6.  What are the upper and lower boxes for each bank?  Please explain.
34.    Table 2.  Please provide units for the numbers in this table. Are they in cm?
35.    Caption to Table 3.  Please provide a more specific and descriptive term than “evolution”.
36.    Line 356.  Delete “then”.
37.    Line 362.  “The share of frost….in THE annual balance…”
38.    Lines 422-424.  I don't see this tested explicitly in the results.  Could the bank erosion rates be presented in grain size categories, for example, to test this more carefully?  Maybe as box plots supported with statistical tests?
39.    Final sentence:  More important would be the adoption of better monitoring methods that can assess changes over larger spatial areas remotely: terrestrial lidar and structure from motion image analysis.

Author Response

Thank you very much for review and all sugestion

Comments and Suggestions for Authors

The manuscript needs some attention before it should be published.  My comments mostly involve improving the presentation (writing, some small typographical errors, better annotation of some of the details in figures and tables) and are relatively minor.   I have also suggested some additions to the discussion of materials and methods (how is grain size assessed, for example).  The authors should also address new high resolution methods of remotely mapping riverbanks using terrestrial LiDAR and structure-from-motion photography.  These methods, while somewhat time-consuming, should ultimately replace erosion pins which invariably must interfere with the process being measured in serious ways.– Thanks for the comment and suggestions. We are now conducting research using laser scanning which allows us to extend the range of measurements. The nearest results shold be available at brek of 2021/2022.

 

I would also like the authors to provide some assessment of the generality of their results.  They find that fluvial erosion exceeds that of frost by a considerable degree.  Do they expect this result to apply to most banks, or is this only a feature of their study site?  Why or why not? – We refrain from providing our assessment before conducting research over a longer period, so that the impact, apparently great, of extreme events, occurring once in several years, can be evaluated.

 

An additional reference to consider:  Pizzuto, 2009, Geomorphology, in which fluvial processes account for 87% of the total erosion, with frost processes accounting for the remainder. – We know your research and we could refer to it in our paper but comparing results obtained at various river banks is difficult. Our observations suggest that with only one element different in the environment, the rates can be entirely different. We have omitted such comparison because the rate of bank retreat depends on so many factors, including kind sediment in the banks, its consolidation, vegetation, exposition (especially in frost processes) or the size of the river and a kind of ots bottom (especially during floods).

 

Overall, I would judge this to be a useful and interesting set of observational data that clearly describe the relative important of frost and fluvial erosion in a single watershed.  The data are unusually clear and therefore interesting.  This is a case study which seems to have local importance without providing much new generally applicable information, but of interest nonetheless to fluvial geomorphologists and others who wish to better understand river bank erosion. – Thank you for the evaluation. We are continuing our studies in such a way that they could have a wider application.

 

Some detailed comments:

 

1. Introduction - placeholder text from the journal’s template seems to be here, rather than the author’s introduction. – sorry, we have corrected the serious mistake.
2. Lines 37-38 - List is anthropogenic effects is somewhat brief - many others to note. – a few were added
3. Line 40 - colon does not seem appropriate here.- changed
4. Paragraph beginning in line 45 - This is an odd review. Too short and lacks focus. - changed
5. Line 47 - Lawler is misspelled.- changed
6. Line 106. Based on the maps provided and the discussion later in the manuscript, it doesn’t seem as if the study sites were established at straight sections.  This is misleading. – The scale was chosen so that all study sites fit in one figure. Unfortunately at this scale locations of some points may seem to be not in straight sections, though in fact, they are. I have slightly corrected the picture.
7. Materials and methods - The reader needs to know more about the river. Classification?  Gravel or sand-bed?  Riparian vegetation?  Any influence from engineering structures?  Land-use in the watershed (e.g., any urbanization or other anthropogenic land use)? Dams or other structures that would modify the frequency of flows?  Any confinement by bedrock or other non-alluvial substrate?–  all the study site have been set in places free of vegetation, with gravel substrate, where no human-made structures alter the flow. The material in the banks in described later in the text. We added this information in the text.Materiał budujący brzegi został omówiony w później części pracy. Informacje powyższe, o których nie było mowy w tekście zostały dodane
8. Lines 141 and 144. Please note in these figure captions that the metro and stream gauging station locations are indicated in Figure 3.- changed
9. Line 148. I wondered here about the spacing of the pins.  Could these details be given here rather than later?  Or at least a note stating that it will be discussed later? – we have added photographs with pins visible. A more detailed description would partle repeat the information in the section Results
10. Line 151. What methods are used to define the grain size characteristics of the bank sediments?  This is important.– grain size was determined by sieving.
11. Line 153. I think Wolman's 1959 paper in the American Journal of Science is the first use of erosion pins.  Cite. - added
12. Line 161. If it is important to include more up-to-date methods, then terrestrial lidar and structure-from-motion image analysis should be mentioned.  See, for example, O’Neal and Pizzuto (2010) in Earth Surface Processes and Landforms, for example. Really no use uses PEEPs as far as I know, anyway. – added in text
13. Line 165. “Integrated” is misspelled.- changed
14. Line 166. Sentence is not clear - please revised. this fragment removed
15. Line 170. Greater than what? Please clarify.– this fragment removed
16. Line 171. “Separated individual plots”?  I don’t understand what this means.  Please clarify. – this fragment removed
17. Lines 173-174. Does this mean that basal erosion was not measured?  Please clarify. – Yes, erosion at bank base was not measured. The pins could not be inserted there. Moreover this part of bank is partly covered by material fallen from the bank.
18. Line 175…..” deep enough to resist for a long time….” Please clarify what this means. – the pins should be placed in the ground below the depth of its freezing. This is important, because if inserted at a lower depth they would react together with the ground. Wnen set deeper, they stay anchored and are not displaced durint the ground’s swelling and shrinking and what the show is the loosening of the bank sediment.
19. Lines 185-190. This listing of dates would be better placed in a table.  It is difficult to follow in the text, and unnecessarily detailed. – modified according to the suggestions.
20. Line 193, caption for figure 3. I think “used” can be deleted. - changed
21. Line 194. Subheading “Site 1” is not very descriptive.  What information about Site 1 is provided. –  the names of the study sites were not used here because they situated quite close to one another which could lead to confusion.
22. General comment: The large number of erosion pins must have had some impact on the erosion processes, providing some degree of bank reinforcement, or focusing stream erosion through eddies around the pins and so on.  This should be discussed somewhere. – the ersosion pins in the banks influence the stability and strength of the banks to some degree. Nevertheless our earlier studied on clay banks wher the pins were incted manually to much greater depths, without any other equipment, we did not observe any differences between the fragments with pins and those away from them.
23. Line 197. Why is the alluvial gravel “cemented”?  Is this a deposit of the contemporary river, or is it bedrock?  In my experience, contemporary fluvial gravels are rarely cemented.  Please explain in greater detail. The cementation of the gravels is high because they are Neogene
24. Line 198 and elsewhere. The reference to “clay” should be explained and clarified.  In my experience, most fine-grained alluvial deposits are mostly silt, with lesser amounts of clay.  What does the descriptor “clayey” actually mean?  Please reference some standard source for terminology so the reader will understand how much clay is present in these deposits.   Also please explain how the clay was identified.  Was a lab test performed, or is this description based on visual observation in the field?  This is important. The particle size distribution of mineral sediments was determined by the sieve-areometric method after Mycielska-Dowgiałło (1998), and texture was determined using the FAO-USDA scale
25. Line 204 - “clay layer”. See comments above. The particle size distribution of mineral sediments was determined by the sieve-areometric method after Mycielska-Dowgiałło (1998), and texture was determined using the FAO-USDA scale
26. Line 204. “The bank is there”.  Please revise to improve writing.-
27. Line 216. “Ros”?  Typo? – Yes. Corrected to „rows”
28. Line 217. The separation referred to here is only present at low flow, right?  Please clarify. – this is valid for medium discharges. At such flows were the pins emplaced.
29. Figure 5 - Are these grain size percentages MEASURED or estimated visually in the field? Please clarify somewhere in METHODS. – added to METHODS
30. Line 245 - “sandy-clayey”. Please explain or provide a reference for these terms.  Presumably they have precise meanings. - The particle size distribution of mineral sediments was determined by the sieve-areometric method after Mycielska-Dowgiałło (1998), and texture was determined using the FAO-USDA scale
31. Line 248. “id” - typo? – Yes, corrected to „is”
32. Table 1 - is the column “type of alluvium” supposed to summarize the characteristics of the full bank height? Please clarify.– this column describes the type of sediment predominating in the bank
33. Figure 6. What are the upper and lower boxes for each bank?  Please explain. – upper fields show the amounts of erosion controlled by frost. The lower fields – those by fluvial processes.
34. Table 2. Please provide units for the numbers in this table. Are they in cm? – Yes, centimeters. Added in the table.
35. Caption to Table 3. Please provide a more specific and descriptive term than “evolution”. - changed
36. Line 356. Delete “then”. - corrected
37. Line 362. “The share of frost….in THE annual balance…” - corrected
38. Lines 422-424. I don't see this tested explicitly in the results.  Could the bank erosion rates be presented in grain size categories, for example, to test this more carefully?  Maybe as box plots supported with statistical tests? – such a comparison did not give any sensible results because of the different degrees of bank cementation. Separating the influence of grain-size and of cementation proved impossible.
39. Final sentence: More important would be the adoption of better monitoring methods that can assess changes over larger spatial areas remotely: terrestrial lidar and structure from motion image analysis. – we fully agree. This why we are now conducting laser scanning of the banks in order to evaluate the same phenomenon by various methods. We continue the use of erosion pin so as to obtain the good comparison of both methods.

Reviewer 3 Report

English needs to be improved throughout.

Line 35: This should be Introduction.

Line 40: activity of running water and rain should be replaced with ‘fluvial’

Introduction: Update references especially those quantity of erosion. There are several papers published in the last few years.

Line 63: 1000 meters in one year or yearly? This seems like a lot of erosion.

It should be discussed that subaerial erosion, fluvial erosion and mass wasting are not independent processes, but can occur over time on the same bank. Subaerial erosion can weaken the soil, fluid erosion can undercut the bank and mass wasting can cause large chunks of top soil to erode.

While fluvial erosion and mass wasting can occur in any stream, aerial processes is limited to streams where the water freezes and thaws throughout the year.  What percent of the world has subaerial erosion?

Fluvial erosion can occur throughout the year.

Line 116: List the country. The map should be Figure 1.

Line 134: Add River after Wielki Rogoznik

Figure 1: Can’t read the axis labels.

In Materials and Methods start out with Study Site section. This should include general information about the study site. You can then have separate sections that discusses how temperature and water depth were measured. The actual values should go in Results. Put general information in Study Site and add references. Data you measured should go in Results.

Line 123: Move to Results

Add Figures 1 and 2 to Results

Did you also measure the soil temperature? The air temperature is not the same as soil temperature.

Line 147: add River after Rogoznik

Line 148: How many rows?

Line 161-162: Delete. Application of an Ultrasonic Sensor to Monitor Soil Erosion and Deposition is a good reference that summarizes different methods of measuring bank erosion.

 

Why not hammer in the pins 90 or 95 cm?

Figure 2 doesn’t have water level, but discharge. Do you have water depth?

Line 181-183: This should go in a separate section.

Line 202: 40 what?

Figure 4: Add more description in caption. Do you have aerial images to illustrate instead of drawings?

Figure 5: Add more description in the study site. What do you mean by mud? Mud consists of sand, silt and clay. What is phi?

I’d like to see a figure with images of the banks.

Line 245: What do you mean by “washed at its feet by the river’?

Line 246: Replace muddy with more accurate soil description.

Line 248: What is ‘id’?

How did you identify the location of the five study sites?

Results:

Line 275: What do you mean by ‘exceptional’?

Line 277: Replace ‘uneven’ with consistent.

How do you define if erosion was caused by fluvial processes, subaerial processes or both? In Introduction, Methods and or Discussion, discuss other papers that have compared erosion by the three erosional processes.

When you state that erosion from frost occurred, what was the water depth during that period? How do you know it was from freezing/thawing?

How often were the bank pins measured?

Figure 6: Add details to caption. Legend is too small to read.

Lines 334-335: Use fluvial and mass wasting to describe the processes.

Table 2: Add details to caption.

Table 3: Do you mean the percentage of total erosion caused by frost phenomena?

Line 364: replace ‘never’ with ‘not’

Line 366: I don’t think mass movements is a frost process. It’s due to the bank being geotechnically unstable due to undercutting

 

Author Response

Thank you very much for review and all sugestion

 

English needs to be improved throughout.

Line 35: This should be Introduction.  – Yes, corrected to: 1. Introduction

Line 40: activity of running water and rain should be replaced with ‘fluvial’– changed to “fluvial”

Introduction: Update references especially those quantity of erosion. There are several papers published in the last few years. – added: Hooke 1979, Duong Thi T., Do Minh D. 2019.

Line 63: 1000 meters in one year or yearly? This seems like a lot of erosion. – the authors (Pilarczyk, K.W., Havinga, H., Klaasen, G.J., Verhey, H.J., Mosselman, E., Leemans, J.A. Control of bank erosion in the Netherlands. State-of-the-art.Conf. Hydr. Eng. ASCE New Orleans, 1989, 1–32) give the value of 1000 m.

 

It should be discussed that subaerial erosion, fluvial erosion and mass wasting are not independent processes, but can occur over time on the same bank. Subaerial erosion can weaken the soil, fluid erosion can undercut the bank and mass wasting can cause large chunks of top soil to erode.

While fluvial erosion and mass wasting can occur in any stream, aerial processes is limited to streams where the water freezes and thaws throughout the year.  What percent of the world has subaerial erosion?

Fluvial erosion can occur throughout the year. – So think we. However, where periodical freezing and thawing occurs, the frost processes stimulate the mass movements and fluvial erosion.

Line 116: List the country. The map should be Figure 1. – Fig. moved from lines 191-192 to 119

Line 134: Add River after Wielki Rogoznik – changed

Figure 1: Can’t read the axis labels. – legibility improved on axes  in Fig. 2A

In Materials and Methods start out with Study Site section. This should include general information about the study site. You can then have separate sections that discusses how temperature and water depth were measured. The actual values should go in Results. Put general information in Study Site and add references. Data you measured should go in Results. – the section Material and Methods was rearranged

Add Figures 1 and 2 to Results - Dodaj rysunki 1 i 2 do wyników  - moved to Results

Did you also measure the soil temperature? The air temperature is not the same as soil temperature – ground temperature was measured using ground termometer at the depth of 25-30 cm

Line 147: add River after Rogoznik- changed

Line 148: How many rows? – detailed sitribution of the pins is described for each site

Line 161-162: Delete. Application of an Ultrasonic Sensor to Monitor Soil Erosion and Deposition is a good reference that summarizes different methods of measuring bank erosion.  – this fragment dropped

Why not hammer in the pins 90 or 95 cm? – because the ground may freeze to a greater depth and the pin would move in the ground.

Figure 2 doesn’t have water level, but discharge. Do you have water depth? -– The depth of water at gauge sites is marked as the 0 cm line.

Line 181-183: This should go in a separate section. - Tekst: During the study period we monitored water levels in the Wielki Rogoźnik and Czarny Dunajec rivers at two gauge stations: Ludźmierz and Koniówka (Figure 2) and air temperatures at the nearby station at Ratułów (Figure 3).  – moved to Study Sites

Line 202: 40 what? – corrected: 40 m;

Figure 4: Add more description in caption. Do you have aerial images to illustrate instead of drawings? -– Legend to Fig. 4 corrected. Location of the study sites (1-5) relative to the channel relief and valley bottom. At this scale air photos are less legible than a drawing.

 

Figure 5: Add more description in the study site. What do you mean by mud? Mud consists of sand, silt and clay. What is phi?    – Mud is a mixture of grains of various size (sand, silt and clay) in washed sediment. Phi – are grain size intervals according to the FAO (2006) standard.

I’d like to see a figure with images of the banks. – Fig. 7 shows one of the study sites        

Line 245: What do you mean by “washed at its feet by the river’? – There is no scree there at base of the bank. The stream directly undercuts a vertical bank.

 

Line 246: Replace muddy with more accurate soil description. –„It is built of a layer of sandy-clayey alluvium 1.8 m thick at the base, overlain with alluvial muddy-sandy clay 0.7 m thick (Figure 5-4).– It is built of alluvium fining upwards. A thin layer of gravel is overlain by sandy-muddy alluvium with intercalations of clay in the upper part. These are overlain with muddy-sandy sediment 0.7 m thick.

Line 248: What is ‘id’? – a typo. Corrected

How did you identify the location of the five study sites? - We tried to select sites differing in bank structure and position relative to the main current. We have selected them basing on differences in elevations and thicknesses of sediments in bank profiles, straight or curved line of the bank, channel width and the presence or absence of scree at the bank base..

Results:

Line 275: What do you mean by ‘exceptional’? - changed

Line 277: Replace ‘uneven’ with consistent. – “uneven” changed to “consistent”

 

How do you define if erosion was caused by fluvial processes, subaerial processes or both? In Introduction, Methods and or Discussion, discuss other papers that have compared erosion by the three erosional processes.- Basing on our field experience we think that activation of fluvial erosion correlates with abundant or long-lasting rainfall and with floods. These processes occur usually together in summer semester, but in winter semester, when there are no floods, bank erosion is mainly the result of subareal processes. This is the norm for the rivers in the temperate climate zone (Starkel 1972; Hooke, 1979).

When you state that erosion from frost occurred, what was the water depth during that period? How do you know it was from freezing/thawing? – When freezing occurs on active surface of a mountain river bank, the water level in the river does not rise, but upon thawing, water level rise in the river is delayed and mass movements begin (falldown, creep) without the participation of river flow. The trigger for both processes is water provided by thawing of the river bank surface. So the water depth in the channel (unless a flood occurs) does not play any role.

How often were the bank pins measured? – added Table 1

Figure 6: Add details to caption. Legend is too small to read.- Dodaj szczegóły do podpisu – The legend was changed to: The amounts of river bank retreat and vartiability in erosion/accumulation of erosion pins in individual rows at study polygons on study sites 1-5, as a result of frost and fluvial processes.. The letters are enlarged

Lines 334-335: Use fluvial and mass wasting to describe the processes. – changed to: „fluvial and mass wasting”

Table 2: Add details to caption – Table title changed

Table 3: Do you mean the percentage of total erosion caused by frost phenomena? – this percentage share of frost processes in bank retreat in the annual balance of total bank erosion.

Line 364: replace ‘never’ with ‘not’ – done

Line 366: I don’t think mass movements is a frost process. It’s due to the bank being geotechnically unstable due to undercutting – Not necessarily. Ice expands fractures in alluvium and upon thawing it provokes detachment of blocks or individual grains and these move to the bank base by sliding or rolling. When the steep bank surface becomes moist upon thawing, another mass movement process begins – creep. Its effect exceeds in gravelly-sandy alluvium the results of all other processes.

 

Round 2

Reviewer 1 Report

Dear Authors, 

1. I still recommend making the text of the "Aim of the paper" section part of the Introduction, but not as a separate section.
2. I recommend avoiding the use of "erosion pits" throughout the text. As I wrote in one of my previous comments, you are not studying the lateral erosion of rivers but the banks' retreat due to the combined (!) action of lateral river erosion and frost processes. Therefore, please use the correct phrase.
3. Your answer to my penultimate comment from the last review on the possible influence of river meandering processes on your results should be somehow highlighted in the work. This is an important issue and should not be avoided. If you have not investigated this issue, it should be included in the new "Research Limitations" section. In general, this section should be in any scientific research, especially in those where some factors are not considered for one reason or another.
4. Line 37. “The amount of river banks erosion by exogenous processes in rivers is locally varies.” Did you mean "is locally varied"? Again, please check English throughout the text.

Author Response

Thank you very much for review and all sugestion

1. I still recommend making the text of the "Aim of the paper" section part of the Introduction, but not as a separate section. – Following the reviewer’s suggestion we combined „Aim of research” with a part of introduction.
2. I recommend avoiding the use of "erosion pits" throughout the text. As I wrote in one of my previous comments, you are not studying the lateral erosion of rivers but the banks' retreat due to the combined (!) action of lateral river erosion and frost processes. Therefore, please use the correct phrase. - We insist that the term „erosion pins” is the proper one. It is used in most paper dealing with this method (e.g. Lawler, D.M., Grove, J.R., Couperthwaite, J.S., Leeks, G.J.L. 1999; Luppi, L., Rinaldi, M., Teruggi, L.B., Darby, S.E.,, Nardi, L. 2008; Couper, P., Scott, T., Maddock, I. 2011). We understand, similarly as the reviewer, that the erosion-pins method provides the measure of bank retreat due to both, fluvial processes and frost phenomena. It is precisely their combined effect what is measured by the use of metal rods. It remains a semantic question weather bank retreat due to frost phenomena and resultant mass movements is covered by the term „erosion.”
3. Your answer to my penultimate comment from the last review on the possible influence of river meandering processes on your results should be somehow highlighted in the work. This is an important issue and should not be avoided. If you have not investigated this issue, it should be included in the new "Research Limitations" section. In general, this section should be in any scientific research, especially in those where some factors are not considered for one reason or another. - We have not undertaken the study on the impact of river meandering on the rate of bank retreat because we had no reference data over the whole length of river bends. We have selected study sites considering not only their position in straight or curved sections of river channels but we have also tried to select sites with various lithological sequences in the banks. We have added explanation to the Introduction. Moreover, the Wielki Rogoźnik river is not a meandering river: straight sections prevail, with some bends. We agree that meandering may influence the rate of bank retreat. This is an interesting topic by addressing it would require another design of study sites and extensive studies including hydrology and morphology of the river channel.
4. Line 37. “The amount of river banks erosion by exogenous processes in rivers is locally varies.” Did you mean "is locally varied"? Again, please check English throughout the text. - We sent the article to english editing in the journal and everything should be fine now

 

 

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors have adequately addressed my comments.

Author Response

We sent the article to english editing in the journal and now everything should be fine

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.