Multidata Study to Evaluate the Impact of Submarine Outfall in a Beach Sedimentary Dynamic: The Case of Samil Beach (Galicia, Spain)
Round 1
Reviewer 1 Report
Please correct these few mistakes
Line 94 fine-grained sediment (fine sand) – sand belongs to medium-sized grains.
Line 158 after 16 points please insert in parenthesis (Figure 3).
Line 235 insert dot after parenthesis.
In References between author's name, commas and semicolons were used. Please correct.
Line 651 odeling? Please correct.
Author Response
Dear reviewer 1
Thanks for your constructive reviews
Ana
Reviewer 2 Report
The Authors addressed all my comments, then in my opinion the paper can be accepted in present form.
Author Response
Dear reviewer
Thanks for your constructive reviews
Ana
Reviewer 3 Report
In my opinion the manuscript can be accepted in the present form.
Author Response
Dear reviewer 3
Thanks for your constructive reviews
Ana
Reviewer 4 Report
The reviewer is satisfied that all of their queries and questions have been addressed in the resubmitted manuscript.
Author Response
Dear reviewer 4
Thanks for your constructive reviews
Ana
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.
Round 1
Reviewer 1 Report
Manuscript " Multidata study to evaluate the impact of submarine outfall in a beach sedimentary dynamic: the case of Samil beach (Galicia, Spain)“ authors: Aimar V. Lersundi-Kanpistegui, Ana M. Bernabeu *, Daniel Rey, Rafael Díaz; is well writen and present interesting research results, but I have few remarks.
Line 143 – the authors writed that sediment samples were taken at 16 stations. Can we see this on figure? Please insert this points on Figure 1
Line 144 – Van Veen drag – in literature is ussually use termin Van Veen grab
Figure 3. What is the meaning of different colors. According to line 151 it is Md. Plrease emphasize this in text of figure.
In discussion chapter 4.2., authors mentioned equations. This equations belongs to Methodes. In these section leave only calculated values and discussion about them.
According my oppinion it would be desirable that authors cite some recent work or works (published in the last year).
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper is well written and well organized. However, in my opinion it could be improved if the authors can fix the following issues.
- The Introduction should be a separate section from the Study area.
- Moreover, the Introduction should describe the current state of the research, which is not the case of the present paper. A bibliographic research on the present and similar topic is completely missing. For example, the authors could describe the approach of other papers on simulations of nearshore sediment transport dynamics, the influence of wave motion, wave – current interaction, etc.
- Also, the set-up of the numerical model is not well described. For example, there is no reference to initial and boundary conditions applied, which is the key point of any simulation.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 3 Report
The manuscript Very interesting data “Multidata study to evaluate the impact of submarine outfall in a beach sedimentary dynamic: the case of Samil beach (Galicia, Spain)” addresses a relevant topic with the scope of marine sciences and the JMSE journal. It is supported in a good set of new data and the authors undoubtedly have faced great challenges in addressing this theme. However, it seems that the work is written more like a technical report than a research paper (framing the approach and results in an international research context is lacking) and, in the present form, has low relevance to an International audience because is too site specific. The modelling approach is also weak as the details of model application are missing, the representativeness of wave conditions is not assured, and there is lack of validation data. Without that, and considered the complexity of the target area, is very difficult to have confidence in model results.
Please consider the following comments and suggestions.
Abstract:
1-The work should be framed in an international context and not only in Galicia and the Samil beach. The introduction should be reduced and more focused. The objective of the work should be more clearly stated.
Introduction
2-The introduction is too large and should be more focused. It should also be re-written to highlight its interest an international audience.
Study area
3-Figure should 1 should be improved and the routing of the pipeline in entire beach included.
4-Description of wave climate is based on quite old data. This is especially important for the representativity of SW component and their link with high energy conditions. As there is a lot of more recent data their use is recommended (see for example Lorente, P., Sotillo, M. G., Aouf, L., Amo-Baladrón, A., Barrera, E., Dalphinet, A., ... & Basañez, A. (2018). Extreme wave height events in NW Spain: a combined multi-sensor and model approach. Remote Sensing, 10(1), 1.)
5-It is not clear why routing did only include two options and, for example, does not include an option that does not cross the sandy beach.
Methodology
6-A map with bathymetric and side scan sonar coverage and location of the samples should be included.
7-Numerical simulations: the simulated wave cases are not representative of the offshore wave regime – the use of the adopted test case should be justified in light of existing wave data and modelling results (the justification given in the text is clearly unsatisfactory). The description of the modelling approach should focus on the site-specific application conditions (physics used, computational grid…) and not on general considerations. Model results should be validated, at least in the hydrodynamic component.
Results
8-Figure 2 should be improved as is rather confusing. For example, is difficult to perceive the location of the profiles and the exact location of the pipelines. Maybe the best way to represent these elements is to present the original figure and another one (side by side) with a clear representation of notable elements (in a similar way seismic profiles are represented).
9-Figure 3 should represent sampling location and units of the variable that is represented (not described in the legend). It the “median grain size of the sand fraction in the seabed sediment” represented over rocky outcrops?
10-Figure 4 the location of the images should be represented in a location map.
Seasonal dynamics of Samil Beach
11-It is difficult to justify that 2.5 m can be considered a storm at Galicia coast. Wave modelling should be developed using a lot more representative sea states.
12-Modelling results seams to indicate that some places are dominate by erosion both in winter and summer – does this matches with observations? How can the profile results have been modeled? Does the model include swash processes?
Pipeline emerging depth in the northern route
13-Considering that this is a sheltered site, the offshore wave regime should not be used to compute the closure depth.
14-Line 507. It is also important to not that closure depth is not related to limit of sediment movement but instead of significant morphological changes. It is also important to refer the closure depth to a specific vertical datum as tides as relevant at the site.
15-The statement in the abstract “The results showed that the area of interest is a low energy” contradicts the initial sentence of the discussion where authors state that this is a “highly dynamic sedimentary system”.
16-To describe depth relationships is better to use the term shallower and deeper rather than higher, lower, until, … (as already mostly used in the manuscript).
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 4 Report
The manuscript describes and discusses a new proposed submerged pipeline construction to discharge treated water in the central channel of the ría and the interaction between alternative designs with the sediment dynamics of the beach. The present study is based on high resolution bathymetry data, seabed physical characterization, granulometric study of the superficial sediment, and numerical simulation of the tide, wave climate and sediment transport in low and high energy conditions using open source Delft3D software. The model revealed that there is significant sediment movement until 7.4 m isobath, and that the pipeline would not alter the general transport dynamics of the beach, but it would interact in the shallowest section. The main conclusion of this work states that the future structure would not alter global sediment dynamics of the beach.
General and Specific Comments
The authors are encouraged to improve command of the English language
Use of capitals when referencing beaches, islands, etc. (e.g. Samil Beach, Toralla Island, Ria)
- Introduction:
Page 1 of 17, Lines 31-36: Authors should look to provide relevant references
Page 2 of 17, Lines 68-71: Look to confirm aim of study here aligns with the aims reported in the abstract
Page 3 of 17, Figure 1: Can the location of the existing pipeline be included in the figure?
Page 3 of 17, Line 95: Can the authors indicate if the seasonal fluvial discharge included in the hydrological model and or any associated sediment loadings? Please discuss were relevant.
- Methodology
Page 4 of 17, Line 143-144: Authors to provide commentary to confirm collected data is sufficient resolution to ensure data is representative of in situ conditions.
Page 4 of 17, Line 160-161: confirm need for italic font.
Page 5 of 17: Authors are encouraged to provide more hydrodynamic model specific inputs commentary, how was the hydrodynamic model output validated against measured hydrodynamic data? Please provide validation commentary/results regarding the hydrodynamic model output and details of the measured data used. This requires explanation.
Page 5 of 17: Authors are encouraged to provide more wave model specific inputs commentary, furthermore how was the wave model output validated against measured wave data? Please provide validation commentary regarding the model output. This requires explanation.
Page 5 of 17, Table 1.: Include decimal (.), not comma (,) when reporting Hs values.
Page 5 of 17: Authors are encouraged to provide more morphodynamical model specific inputs commentary, including model resolution, model time step, etc.,
Page 6 of 17, Line 233: Consider adding term ‘lettering’, i.e., (in black lettering, see text)
Page 6 of 17, Line 251: Formatting edit- Remove spacing between figure number and sub-figure letter, i.e. (Fig. 2d,…)
Page 7 of 17, Line 259: Edit Toralla inland to Toralla Island
Page 7 of 17, Figure 3: In methods section look to provide description regarding spatial interpolation method of 16 data points used to prepare this figure. Additionally, please look to provide key for figure describing values and units.
Page 7 of 17, Figure 4: Authors should look to provide North arrow to provide orientation of figures and scale bar. Additionally, consider providing reference (large scale, inset figures) of side scan sonar images in relation to study area
Page 8 of 17, Section 3.4 Seasonal dynamics of Samil beach: The authors are encouraged to provide summary table of measured waves statistics and how the modelled/considered seasons compare.
Page 9 of 17, Figure 5: add units of figure. Additionally, confirm scale bar is consistent with magnitudes of reported results in text.
Page 9 of 17, Line 330: Consider reminding readers P1, P2 and P3, depicted in Figure 1.
Page 10 of 17, associated text with Figure 6: Can the authors provide determination and commentary of volumetric change?
Page 10 of 17, Line 465: Ensure acronym for SSS has been previously explained.
Page 10 of 17, Line 488: Include reference [15] associated with Birkemeier (1985)
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
The revised manuscript has improved and I understand that, at this stage, the limitations concerning observation and modelling designs cannot not be overcame (for instance, the representativeness of wave climate is not assured (as high waves can dominate offshore morphological changes) and model cannot be validated) which limits the usefulness of the results obtained and paper conclusions. However, in my opinion, the methodology and data presented deserves publication so, even without considering the above constraints, the data should be presented as clear as possible. In this sense, please consider the following suggestions (that were not clarified in the revision):
- The objective must be clearly stated in the abstract. It seems relevant to that state the study focusses the submarine section of the beach, where there still is a research gap.
- Figure 3 – Medium grain size should not be represented over rocky outcrops: the representation of rocky outcrops is fundamental to understand the sediment dynamics over the area, and sedimentary links with the subaerial and submarine sections of the beach – in this sense the two routing alternatives are quite different (at least in what I could perceive using google earth images). Note: stating that interpolation was performed by kriging is not sufficient to describe the interpolation method because results strongly depend on the variogram used.
- Representation of the location of Side Scan Sonar figures is missing.
- L223 - The representativeness of modelled wave climate must be clearly presented and discussed (this key to help the reader to understand the results). I must stress that is still not clear if this are representative winter / summer conditions or not (for example, what is the frequency of SW summer waves?) If it is, please state it the manuscript.
- “When a hard intervention is performed in a highly dynamic sedimentary system, as in this case” – this is not exactly true because this is a sheltered environment,
Reviewer 4 Report
The reviewer is satisfied that all of their queries and questions have been addressed in the revised manuscript. Even though the authors acknowledge that a direct attempt to improve the use of ‘English’ was not made, the revised manuscript does represent an improvement of the use of English throughout the manuscript.
