Prolonged Response of River Terrace Flooding to Climate Change

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript investigated the evolutions of multiple sedimentary facies overlying the terrace surfaces at different sites from the Yellow River and Yangtze River including the Ledu, Pingan, Jinxing, and Silong. It demonstrates a general fining-up tendency in deposits interrupted by shorter-term events of flooding or non-deposition. This reflects a slowing down of flow intensity as the river incises progressively deeper and a prolonged response in the evolution of river terraces to climate change. The manuscript is well written and the associated processes were clearly explained. I recommend publication following minor revision. My comment that the authors many take into account when preparing their revision is general overall. I suggest rename the title of each subsections in Section 3 according to the name of the investigated sites. It is best that the current names can be simplified to improve the readability and legibility. Detailed description of the characteristics of the deposits for each site can be put into relevant text (rather than presented as a subtitle). In addition, add a proper citation for “A series of OSL-dates” stated in Line216.

Author Response

Thanks for the review.

Subsection titles modified. Line 216 modified too.

Reviewer 2 Report

Comments and Suggestions for Authors

Check some citations in the text and some small spelling inaccuracies.

Author Response

Thanks for the review.

I did not receive specific suggestions from the editorial board for text revision, maybe later?

Reviewer 3 Report

Comments and Suggestions for Authors

1)      Neither from the Conclusions of the work, nor from the Abstract I received information about the novelty of the results obtained. Consecutive alternations of deposits of different facies composition in the sections of river terraces have already been studied in detail and for a long time (many, many decades) in various regions of the world. This also applies to arid and periglacial conditions of sediment formation in the Quaternary in various regions of Northern Eurasia and North America. In other words, the work has neither conceptual nor methodological novelty. The authors did not even identify regional novelty that might be useful. This is the main flaw of the manuscript.

2)      Geological sections are in no way accompanied by paleogeographic detailed reconstructions of either climate and/or landscape, which would make it possible to better understand changes in the conditions of formation of the studied deposits.

3)      Granulometric analysis is just one type of analysis that can help in diagnosing the conditions for the formation of loose deposits. It's not always reliable. Therefore, its results need to be supported by the results of other independent analyses. For example, this applies to the aeolian facies you identified. They are more or less reliably identified using both granulometric and structural-facial (analysis of the features of the location of sediment layers) and morphological (analysis of the morphology of mineral grains) analyses. You don’t have any of this in your work. There are some references to earlier works, but there is little convincing information in the text.

4)      There are no limitations of the study.

The work requires rethinking and significant revision, based on the adjustment of goals.

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

Thanks for the review.

Comment 1: We agree that the objective of this study was not well highighted. We never planned a sedimentological study of floodplain depoists. As the reviewer states, this would not have been novel. Instead, we focus on the temporal evolution in floodplain deposition both on long-term and short-term. We discovered a prolonged response to the climate trigger of terrace formation that is supported, where possible, by absolute dating. Thus, we clarified our study objective in the last sentences of the Introduction as follows:

'It is not the intention to describe here the diversity in floodplain deposits which has been done already since, for instance, McKee (1938, 1966) and Leopold et al. (1964). Instead, the temporal evolution and specifically the prolonged and delayed reaction of the river system at the waning and final phase of terrace formation compared with the triggering climatic event are illustrated and discussed in the following cases.'

Comment 2: Furthermore, the regional context of most case studies has been decribed and discussed in peer-reviewed papers before (amply referenced) and thus we do not like to repeat that. The novelty of this paper is not in explaining regional morphological development.

Comment 3: We agree that eolian evidence of deposits may be substantiated by other characteristics than grain size (for instance grain morphoscopy). However, we still believe that granulometry is well-appropriated to evidence the eolian origin (see arguments and examples e.g. in Vandenberghe 20113 and Vandenberghe et al 2018). Thus, we oppose to the reviewers statement that 'granulometry would not be reliable'. In conjunction with morphological analogues of present-day dune forms with their grain-size characteristics and sedimentary structures (described in more detail in Wang et al 2019, and thus not repeated here), we feel that the eolian origin is sufficiently proven.

Comment 4 is not well understood. Sorry.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript does not have a (sub)section devoted to the limitations of the study. If you are not familiar with this concept (limitations of the study), then please look at other articles where this information is presented.

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

Dear reviewr,

Answer to your comment/suggestion 'The manuscript does not have a (sub)section devoted to the limitations of the study.'

In comparison to the originally submitted draft and your previous useful comments, we modified the Introduction and Conclusions sections to specify exactly what is the intention of the paper and what is not. In our opinion that should be sufficiently clear now and we think a separate (sub)section is not needed.