Application of Hydrological Modeling Related to the 2011 Disaster in the Mountainous Region of Rio De Janeiro, Brazil

Round 1

Reviewer 1 Report

Dear Authors

I reviewed the manuscript APPLICATION OF HYDROLOGICAL MODELING IN THE 2011 DISASTER IN THE MOUNTAINOUS REGION OF RIO DE JANEIRO. Current and very useful topic, I suggest that it be published, with minor corrections.

 - Subchapter 2.1. (Study Area) - Please add climate data: climate formula according to Kopen, average annual rainfall, rainfall regime, average temperature...

 Subchapter 2.2 (The natural disaster in the mountainous region of Rio de Janeiro in 2011) - please give at least 1-2 sentences about the devastation of the area, whether forests are cut down unplanned, how much this increases the risk of erosion...

 Subchapter 1.3. (SWAT and SMAP hydrological models) - need 2.3.

 Cordially,

 

Author Response

Dear reviewer, 

We tried to change the text according to the recommendations. The responses are found below.

 - Subchapter 2.1. (Study Area) - Please add climate data: climate formula according to Kopen, average annual rainfall, rainfall regime, average temperature...

Thank you for your comment.

Included in section 2.1

- Subchapter 2.2 (The natural disaster in the mountainous region of Rio de Janeiro in 2011) - please give at least 1-2 sentences about the devastation of the area, whether forests are cut down unplanned, how much this increases the risk of erosion...

Was included this paragraph in section 2.2 (line 135-138)

"According to the report by Ministry of the Environment of the 657 landslides mapped in the municipality of Nova Friburgo, 90% occurred in areas with some anthropic intervention (Brazil, 2011). Actions such as deforestation, opening of roads, pastures have influenced erosion processes and the destabilization of slopes in this area (Brazil, 2011)."

 Subchapter 1.3. (SWAT and SMAP hydrological models) - need 2.3.

It was corrected in the text

 

The new line numbering refers to the revised manuscript.

 

 Cordially,

Author Response File: Author Response.pdf

Reviewer 2 Report

Please specify in the introduction what is new about this article. The research is carried out with the help of quite often used methods, which does not indicate a novelty in the scientific field.

In the case of figure 1, the map representing the hydrographic basin itself is too crowded with details. If you want to show only the hydrographic network in addition to the location, I recommend removing the background or choosing a more simplified one. The satellite images with the hydrographic network make the map too crowded and it's as if nothing can be read. And in the case of the location of the localities, points or their borders should be placed so that they can be spotted more easily on the map.

Can a graph be added with the amount of precipitation that fell in the study area during the analysis period and the previous one?

Does the low resolution of the numerical model not affect the results?

In the case of map 3a, the color palette is not suitable. I recommend choosing a color palette that varies from green to brown (green for the low areas and brown for the high ones. The scale is also missing for all the images from figure 3.

Please specify in the text what is the scale of the pedological map used.

At line 334 the phrase seems incomplete.

Please check line 354.

The fairly large errors of the results can also be caused by the quality of the entered data. Large-scale data do not have so many details and therefore can generate errors in simulations or analyses. Also, has the DEM been processed, have the errors on it been checked?

Please check the text, some punctuation marks are missing. (e.g. missing points from lines 110, 118).

Author Response

Dear review, 

We tried to change the text according to the recommendations suggested. The responses are found below and we wrote a letter to learn more about the purpose of this study.

Please specify in the introduction what is new about this article. The research is carried out with the help of quite often used methods, which does not indicate a novelty in the scientific field.

Thank you for your comment.

It was included in the abstract. (line 15-23)

"In this study, for the first time, a model of SWAT's complexity was applied to a watershed located in the mountainous region of the state of Rio de Janeiro, a region that, unfortunately, has accounted for thousands of deaths over the past decades associated with mass movements and floods. The SWAT model, besides being able to predict the level and flow of the main course of the river and its tributaries, also enables the calculation of sediment transport in extreme events. Looking from an operational point of view, the work clearly shows how poor hydro-meteorological monitoring, as is the case in this region, makes impossible a good quality prediction for extreme events. It was demonstrated that under these conditions, a simpler and concentrated modeling approach, such as the SMAP model, is able to obtain better results than SWAT."

In the case of figure 1, the map representing the hydrographic basin itself is too crowded with details. If you want to show only the hydrographic network in addition to the location, I recommend removing the background or choosing a more simplified one. The satellite images with the hydrographic network make the map too crowded and it's as if nothing can be read. And in the case of the location of the localities, points or their borders should be placed so that they can be spotted more easily on the map.

Figure 1 was redone in response to these suggestions.

Can a graph be added with the amount of precipitation that fell in the study area during the analysis period and the previous one?

Added as figure 2 (line 93) and figure 3 (line 109).

Does the low resolution of the numerical model not affect the results?

In reality since the resolution of the observed data was very low, this ended up contributing negatively to the higher resolution model (SWAT) and benefited the concentrated model, in this case SMAP. This point is commented on in the conclusions.

In the case of map 3a, the color palette is not suitable. I recommend choosing a color palette that varies from green to brown (green for the low areas and brown for the high ones. The scale is also missing for all the images from figure 3.

Figure 6 was redone in response to these suggestions (line 194).

Please specify in the text what is the scale of the pedological map used.

The pedological map scale is 1:250,000, this information was added in the text (line 198).

Thank you for your comment.

At line 334 the phrase seems incomplete.

It was corrected in the text (line 326).

Thank you for your comment.

Please check line 354.

It was corrected in the text (line 340)

"According to the results, as we can see in Figures 9 and 12, both models predicted the extreme flood event beginning on the 11th. The ERM of the model simulations (Table 7) infers that SMAP performed better in calibration and validation. The ERM of the latter stage is extremely important for evaluating the performance of the model in its predictions relative to the actual event and the reliability of the data generated. In this sense, comparing these two models, the SMAP presented, in this work, a better simulation performance, being more suitable for monitoring extreme flood events."

The fairly large errors of the results can also be caused by the quality of the entered data. Large-scale data do not have so many details and therefore can generate errors in simulations or analyses. Also, has the DEM been processed, have the errors on it been checked?

 These errors have been checked. Regarding the DEM SRTM data, studies accomplished in Brazil indicate that the data are suitable for use a scale between 1:50,000 and 1:100,000, compatible with the other maps used in this project. In addition, at the time our work was carried out, there were no validated altimetric data available that we could compare. Which would result the necessity to collect points in the field, which exceeded the objectives of the project. These studies were added in the text (line 169-172).

Please check the text, some punctuation marks are missing. (e.g. missing points from lines 110, 118).

It was corrected in all text. Thank you for your comment.

 

 

The new line numbering refers to the revised manuscript.

 Cordially,

Author Response File: Author Response.pdf

Reviewer 3 Report

Please check the use of other language, other than English, found in this manuscript.

Comments for author File: Comments.pdf

Author Response

Dear review, 

The present work aims to show the importance of hydrological modeling in the management and prevention of environmental disasters, linked to extreme precipitation events. In addition, it discusses the importance of monitoring networks for the efficient use of modeling.

In this way, the novelty of this work in the scientific community is to show how two models that differ in the amount of input data can be applied in Brazil in view of the quality and quantity of data made available by government agencies. In this study, for the first time, a model of SWAT's complexity was applied to a watershed located in the mountainous region of the State of Rio de Janeiro, a region that, unfortunately, has accounted for thousands of deaths over the past decades associated with mass movements and floods. The SWAT model, besides being able to predict the level and flow of the main course of the river and its tributaries, also enables the calculation of sediment transport in extreme events.

Looking from an operational point of view, the work clearly shows how poor hydro-meteorological monitoring, as is the case in this region, makes impossible a good quality prediction for extreme events. It was demonstrated that under these conditions, a simpler and concentrated modeling approach, such as the SMAP model, is able to obtain better results than SWAT.

The results shown by SWAT may be a reflection of the difficulty of calibrating this model, which requires not only a higher data resolution, but also a greater diversity of Inputs. Despite the results, as seen in the work, the model can provide an idea in an order of magnitude of the  event behavior and the potential areas affected.

We agree that the data quality may have interfered with the SWAT performance, which raises the question of the importance of investing in the monitoring network in Brazil. With a better data scenario, the applications of these more complex models can offer results closer to reality and, consequently, expand to other analyzes that are fundamental for prevention strategies and to increase resilience in the face of natural disasters.

We tried to change the text according to the recommendations suggested. The responses are found below.

• Please check the use of other language, other than English, found in this manuscript.

Thank you for your comment. The Portuguese parts of the text have been removed.

 

The other changes requested were answered in “climate-2220048-review_response.pdf” file. The new line numbering refers to the revised manuscript.

If any further modifications are needed, we are available.

 

 Cordially,

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The changes suggested by me have been well addressed. I believe that the article can be published.