Automatic River Planform Recognition Tested on Chilean Rivers

Round 1

Reviewer 1 Report

This paper discusses the issue of the automatic identification of river reaches and their planform types, such as Single and Trans ones. Further advances with respect to the original proposal by Nardini and Brierley are addressed, and the ability of the algorithm and associated tools to work properly on significantly different rivers while adopting a given same parametrization are explored. The Duqueco, Laja and Biobío rivers (Chile) are analyzed for this purpose. The conclusion is definitely positive, what opens future promising application horizons.

From the point of view of algorithm, the river form classification method and results discussed in this paper are acceptable. However, affected by the accuracy and acquisition time of data sources, the river morphology obtained from these data with different resolutions may be different, so the proposed river morphology characteristics are not invariable. The morphological classification of this variable geomorphic type has variability and contingency, so it should be discussed in this paper.

From the point of view of English reading, this article is written in a variety of expressions such as broken sentences, brackets, etc., which brings some difficulty to continuous reading. It is suggested that it may be better to reduce the expression in brackets and use the detailed expansion method instead.

Line 94, segment between slices 1000-1500 is right?

 

In Figure 1, what’s User and Algorithm？

  

Author Response

Comments and Suggestions for Authors

This paper discusses the issue of the automatic identification of river reaches and their planform types, such as Single and Trans ones. Further advances with respect to the original proposal by Nardini and Brierley are addressed, and the ability of the algorithm and associated tools to work properly on significantly different rivers while adopting a given same parametrization are explored. The Duqueco, Laja and Biobío rivers (Chile) are analyzed for this purpose. The conclusion is definitely positive, what opens future promising application horizons.

From the point of view of algorithm, the river form classification method and results discussed in this paper are acceptable. However, affected by the accuracy and acquisition time of data sources, the river morphology obtained from these data with different resolutions may be different, so the proposed river morphology characteristics are not invariable. The morphological classification of this variable geomorphic type has variability and contingency, so it should be discussed in this paper.

Reply: what you point out here is indeed one of the reasons that motivates the use of such an algorithm, i.e., the ability to monitor in a consistent (and automatized) fashion river change through time. This idea is already addressed in the conclusions (Line 653-5 of the original manuscript) but is now emphasized according to your suggestion since the beginning (new Lines 30-37).

 

Comments on the Quality of English Language

From the point of view of English reading, this article is written in a variety of expressions such as broken sentences, brackets, etc., which brings some difficulty to continuous reading. It is suggested that it may be better to reduce the expression in brackets and use the detailed expansion method instead.

Reply: we now simplified as far as possible the style; however, the use of parenthesis allows us to be much more precise and concise, what we consider to be highly useful in the explanation of specific concepts. As such, we maintained what we considered most useful and corrected the rest.

Line 94, segment between slices 1000-1500 is right?

Reply: yes, it is: the graph in Fig.1 shows AC width along the river and in that segment (slices 1000-1500) is highly variable.

 In Figure 1, what’s User and Algorithm？

Reply: yes, sorry: now it has been clarified in the figure explanation: “The actions performed by the User are in red text, while those performed by the algorithm are in black.”

Reviewer 2 Report

Dear authors,

This paper deals with the application of a procedure that aims to identify automatically the riverbed planform pattern. This procedure has already been published, in this work a new application is implemented aiming to explore the method response in case of sudden and large changes in channel width. Furthermore, some novelties are introduced. The research topic is very interesting, especially thinking at the possible applications of this approach that are well stated at the end of conclusions.

The manuscript is rather clear, even if some sections could be improved and a general revision of English and typing is needed.

General comments

In 2.2 an introduction briefly listing which improvements were introduced could be added before their detailed description.

Results: I would suggest improving the form of this section for example by avoiding to introduce each figure with “here”, in order to make more readable the text. Moreover, figure 23 could be reported at the beginning of this section to show the overall results, namely, the general classification of investigated rivers. This general part could be followed by the site-specific considerations and, ultimately, by figure 24 and its related text.

Figures: Figures related to the results section need more detailed captions to explain the meaning of each map displayed within the figure.

 

Specific comments

Line 75: the active channel is the reference unit for the analysis and, for example to compute channel width, please define the active channel (for examples consider references below).

Line 146: the explanation of the acronym VB is not reported before.

Line 130: could you add a reference for sinuosity?

Line 169 and following: the subject is not clear. In case this general part is referred to the overall method, could it be a section apart located before section 2.2 on improvements?

Line 214: I suggest indicating the names of investigated rivers at the beginning of section 3.1, for example after the first sentence.

Lines 270 (and 75): an explanation on the meaning of active channel could be added. What do you mean with “high waters”? Could “Low-flow channels” be considered for a better explanation? Islands are part of the riverbed/active channel for computations?

Line 271: please state the meaning of “fluvial elements of the floodplain”

Line 282: “Rivers like ours” please explain better “ours”

Line 270: “these UGO (or geomorphic elements); “line 298 “The geomorphic elements and units (GUs)”. Please, try to explain better what units and alements are; objects listed at lines 299-301 could be separated into these two classes.

Line 320: “water channel width of channels” is not clear. Please, rephrase, would it be possible to change into low-flow channel width?

Line 321: Is the distance measured between two active channels or between two low-flow channels?

Figure 14: What is “intake” in legend? Could it be replaced with reservoir?

 

Please consider these references for the active channel definition

- Mandarino, A., Maerker, M., & Firpo, M. (2019). Channel planform changes along the Scrivia River floodplain reach in northwest Italy from 1878 to 2016. Quaternary Research, 91(2), 620-637.

- Nelson, N. C., Erwin, S. O., & Schmidt, J. C. (2013). Spatial and temporal patterns in channel change on the Snake River downstream from Jackson Lake dam, Wyoming. Geomorphology, 200, 132-142.

- Winterbottom, S. J. (2000). Medium and short-term channel planform changes on the Rivers Tay and Tummel, Scotland. Geomorphology, 34(3-4), 195-208.

And for geomorphic units

- Belletti, B., Rinaldi, M., Bussettini, M., Comiti, F., Gurnell, A. M., Mao, L., ... & Vezza, P. (2017). Characterising physical habitats and fluvial hydromorphology: A new system for the survey and classification of river geomorphic units. Geomorphology, 283, 143-157.

Some useful references for planform metrics

- Clerici, A., Perego, S., Chelli, A., & Tellini, C. (2015). Morphological changes of the floodplain reach of the Taro River (Northern Italy) in the last two centuries. Journal of Hydrology, 527, 1106-1122.

- Clerici, A., & Perego, S. (2016). A set of GRASS GIS-based shell scripts for the calculation and graphical display of the main morphometric parameters of a river channel. International Journal of Geosciences, 7(2), 135-143.

A general revision of English and typing is needed.

Author Response

Comments and Suggestions for Authors

Dear authors,

This paper deals with the application of a procedure that aims to identify automatically the riverbed planform pattern. This procedure has already been published, in this work a new application is implemented aiming to explore the method response in case of sudden and large changes in channel width.

Reply: actually, it is not really aiming at that; it is aiming at exploring whether the algorithm can deal with different rivers with no need for re-calibration. However, as an incident, we went through rivers some of which show these sudden width variations and had to deal with that.

 Furthermore, some novelties are introduced. The research topic is very interesting, especially thinking at the possible applications of this approach that are well stated at the end of conclusions.

The manuscript is rather clear, even if some sections could be improved and a general revision of English and typing is needed.

 

General comments

In 2.2 an introduction briefly listing which improvements were introduced could be added before their detailed description.

Reply: ok, we added it to the text.

 

Results: I would suggest improving the form of this section for example by avoiding to introduce each figure with “here”, in order to make more readable the text. Moreover, figure 23 could be reported at the beginning of this section to show the overall results, namely, the general classification of investigated rivers. This general part could be followed by the site-specific considerations and, ultimately, by figure 24 and its related text.

Reply: we modified the text trying to satisfy your request related to the “here” issue. We considered your suggestion to move Fig.23, but we concluded that it is part of the Discussion because it has now been integrated with a new twin figure to point out the role of Holistic Tool.

 

Figures: Figures related to the results section need more detailed captions to explain the meaning of each map displayed within the figure.

Reply: we tried, but the only way to do that without redundancy, would be just to incorporate within the captions the comments that follow the figure; and that would lead to too long paragraphs. So, we kept it as it was.

 

Specific comments

Line 75: the active channel is the reference unit for the analysis and, for example to compute channel width, please define the active channel (for examples consider references below). Reply: ok, reference has been added, thank you

 

Line 146: the explanation of the acronym VB is not reported before. Reply: ok, it has been added, thank you

 

Line 130: could you add a reference for sinuosity? Reply: ok, reference has been added, thank you

 

Line 169 and following: the subject is not clear. In case this general part is referred to the overall method, could it be a section apart located before section 2.2 on improvements? Reply: you are right, thank you, it was not clear. Now we created a specific section for that item.

Line 214: I suggest indicating the names of investigated rivers at the beginning of section 3.1, for example after the first sentence. Reply: done, thank you.

Lines 270 (and 75): an explanation on the meaning of active channel could be added. What do you mean with “high waters”? Could “Low-flow channels” be considered for a better explanation? Islands are part of the riverbed/active channel for computations? Reply: we added a definition of AC which should solve doubts. In any case, “high water” means flows covering bars, i.e., something close to bankfull flow. Islands are not part of AC (and hence not considered in calculations), but they are in AC envelopes (and calculations). You can find operational details in our Manual here: https://www.dropbox.com/scl/fi/eu07ktw1mk7e7jgi60rji/ManualToolBOX-new-2.7.docx?dl=0&rlkey=7hmijo5nbv560za42rqbowofp

Line 271: please state the meaning of “fluvial elements of the floodplain” Reply: sorry, it meant “geomorphic units within the floodplain”. Now corrected, thanks

Line 282: “Rivers like ours” please explain better “ours” Reply: corrected in “like those here considered”.

Line 270: “these UGO (or geomorphic elements); “line 298 “The geomorphic elements and units (GUs)”. Please, try to explain better what units and elements are; objects listed at lines 299-301 could be separated into these two classes. Reply: sure, now it is clearer. Thank you.

Line 320: “water channel width of channels” is not clear. Please, rephrase, would it be possible to change into low-flow channel width? Reply: sure, you are right. Done.

Line 321: Is the distance measured between two active channels or between two low-flow channels? Reply: corrected: low flow channels. Thank you.

 

Figure 14: What is “intake” in legend? Could it be replaced with reservoir? Reply: no, it is a water intake (withdrawal) without reservoir.

 

Please consider these references for the active channel definition

- Mandarino, A., Maerker, M., & Firpo, M. (2019). Channel planform changes along the Scrivia River floodplain reach in northwest Italy from 1878 to 2016. Quaternary Research, 91(2), 620-637.

- Nelson, N. C., Erwin, S. O., & Schmidt, J. C. (2013). Spatial and temporal patterns in channel change on the Snake River downstream from Jackson Lake dam, Wyoming. Geomorphology, 200, 132-142.

- Winterbottom, S. J. (2000). Medium and short-term channel planform changes on the Rivers Tay and Tummel, Scotland. Geomorphology, 34(3-4), 195-208.

And for geomorphic units

- Belletti, B., Rinaldi, M., Bussettini, M., Comiti, F., Gurnell, A. M., Mao, L., ... & Vezza, P. (2017). Characterising physical habitats and fluvial hydromorphology: A new system for the survey and classification of river geomorphic units. Geomorphology, 283, 143-157.

Some useful references for planform metrics

- Clerici, A., Perego, S., Chelli, A., & Tellini, C. (2015). Morphological changes of the floodplain reach of the Taro River (Northern Italy) in the last two centuries. Journal of Hydrology, 527, 1106-1122.

- Clerici, A., & Perego, S. (2016). A set of GRASS GIS-based shell scripts for the calculation and graphical display of the main morphometric parameters of a river channel. International Journal of Geosciences, 7(2), 135-143.

 

Comments on the Quality of English Language

A general revision of English and typing is needed. Reply: we revised as far as possible the whole document.