Effect of Skewness Orientation on Morphological Adjustments in Alluvial Meandering Streams
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe morphological adjustments of meandering rivers and their influencing mechanisms have always been an area of concern for fluvial geomorphologists and river engineers. So far, a series of field observation and analysis as well as flume experimental research have been reported, providing sufficient analysis of the spatial distribution of side bars and deep pools along meander belts of meandering river. The present article investigates the development process of side bars and deep pools in a unconfined meanders with an up-valley skewed, a down-valley skewed, and a non-skewed symmetrical channel using a laboratory flume. Some of the results are comparable to the experimental results of previously reported for confined channels. The reviewer believes that the work is excellent and suggests publishing it after making minor revisions to the shortcomings in the article.
1. The authors introduced the riverbed composition of the flume channel in this article, but did not introduce the riverbank material. It is recommended that the author provide a comprehensive introduction to the material composition of the river channel (including the riverbed and riverbank), in order to help understand phenomena such as bank collapse during the experimental process.
2. Throughout the entire experiment, the meander still maintained its original shape. Please discuss the reason for this? Is it caused by the fine and coarse binary material structure on the meandering riverbank? Or for other reasons?
3. The stability of meandering rivers is also a very important concern, and its representative parameter is even the width to depth ratio of the river. Suggest drawing and discussing the changes in the width to depth ratio of the channel cross-sections along the channel way (with smaller section intervals) for the final experiment channel (5 meanders), and comparing the differences in width to depth ratios at different positions of the meander bends.
4. The secondary numbering in the “research results” section is incorrect and needs to be adjusted accordingly.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors1. Line 85: “The sediment bed consisted of a poorly-sorted medium sand containing minimal fines with a median particle diameter of D50 = 0.75 mm (σ = 0.34 mm) and a particle density of 2500 kg/m3. Please explain why you chose this sediment bed design. Is this particle size suitable?
2. Line 178: Some time steps had higher than desired flow rates. It is better to show a table which included the research result of erosion rates and amounts. In addition, it is necessary to show the statistical analysis for erosion rates and amounts.
3. Line 205: “Aside from the increased bank erosion in M1, differing levels of erosion are also present in other meanders. In the up-valley skewed experiment, increased erosion was observed in M2, M4, and M5.” How about the M3? It is an interesting result. Please explain this difference.
4. Line 266: Pools are more difficult to observe but two can be identified in each meander: one upstream of the apex and downstream of the apex. How to define the pools in this research? How about the middle stream area?
5. Line 282: Based on the research of Abad & Garcia, in their fixed bank flume, the pool did not form but rather the deepest point in the channel bed was scouring at the outer bank. However, in these experiments, a pool formed instead, albeit at the same location. Please explain the reason of difference more detail.
6. Line 329: Influences from bank erodibility affecting how the channel forms in the lab would align with the noted potential effects of vegetation. Could you provide some suggestion for the future research considering the effect of vegetation?
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
