Combining Co$ting Nature and Suitability Modeling to Identify High Flood Risk Areas in Need of Nature-Based Services

Round 1

Reviewer 1 Report

The manuscript entitled “Combining Co$ting Nature and Suitability Modeling to Identify High Flood Risk areas in Need of Nature-Based Services” submitted to Land journal. The authors applied the Co$ting Nature Model to identify the areas which experience high flood risk and low level ecosystem services in the Houston-Galveston Metropolitan Area (HG MSA). The research topic is interesting, but I do not think it is suitable for publication in the current stage. The main reason is that the manuscript focuses too much on the case study and was written like an application of the Co$ting Nature model. Please consider my comments below:

General comments:

• My main concern is the novelty of this study. From the introduction, it is not clear on how does this study contribute to the general knowledge? The authors should at least list similar studies, and figure out what are the gaps in those studies? What is the main contribution of this research in addressing those gaps? In the introduction, they said “this research applies the Co$ting Nature model to the HG-MSA to identify areas that are experiencing high flood risk and low level ecosystem services”. If so, this is just an application of the above model? In contrast, the literature review part about the model is too long and contains unnecessary information. The authors are not selling this software; they only need to provide basic information, such as inputs, outputs, and some application worldwide (shorten your paragraphs). We should either merge this section with Introduction or Methods.
• Please provide the study area with a map showing the location of the study area. The list of data input (or main inputs) can be summarized in a table (with data sources). The section 3.1. is not very clear.
• Are the chosen indices and the weighted factors also applied in other studies?
• In the introduction, they mentioned the period 2001 – 2017. I am just wondering if the model can help you to provide several snapshots over the period. I am not sure if I miss the information, but I can’t find which year did you use to build the maps?

Minor comments:

• There is 2.1, but no 2.2.
• Figure 1: some texts (e.g. legends) are unreadable. Please consider removing them/making them larger.
• Figure 2: in the center of the figure, why there is a straight line which separates the moderate low and moderate region?
• Table 2: should you consider using a pie chart and combine it with Figure 2?

I hope that my comments can help you to improve the quality of the manuscript.

Author Response

Reviewer 1:

The manuscript entitled “Combining Co$ting Nature and Suitability Modeling to Identify High Flood Risk areas in Need of Nature-Based Services” submitted to Land journal. The authors applied the Co$ting Nature Model to identify the areas which experience high flood risk and low level ecosystem services in the Houston-Galveston Metropolitan Area (HG MSA). The research topic is interesting, but I do not think it is suitable for publication in the current stage. The main reason is that the manuscript focuses too much on the case study and was written like an application of the Co$ting Nature model. Please consider my comments below:

General comments:

• My main concern is the novelty of this study. From the introduction, it is not clear on how does this study contribute to the general knowledge? The authors should at least list similar studies, and figure out what are the gaps in those studies? What is the main contribution of this research in addressing those gaps? In the introduction, they said “this research applies the Co$ting Nature model to the HG-MSA to identify areas that are experiencing high flood risk and low level ecosystem services”. If so, this is just an application of the above model?
• Thank you for the comment. We have addressed this issue through adjusting the introduction to highlight the novelty of the research, discussing the methodological contributions of the research in the findings, and adding a paragraph specifying the research gaps and contributions upfront. The paragraph reads: Because locational spatial data and the distribution of ecosystem services are oftentimes unclear, the full protection of ecosystems is not always captured. Due to this lack of spatially explicit data, mapping ecosystem services to advise investment conservations is crucial for guaranteeing that the co-benefits are preserved. While applications of the Co$ting Nature model are limited in the literature due to its relatively new creation, much of the current applications are simply adjustments of the model’s in-ternal inputs to streamline a strategic output. To our knowledge, there have been no connections to other spatial analytic methods, such as suitability modeling, to create targeted overlays to solve existing built environment issues. Such an approach, when focused on flood risk modeling, should be a normalized approach to combining existing areas of ecological services, potential areas of ecological services, and areas at risk of future hazard evens (in this case, flooding). Such a framework will allow planners, re-searchers, and policy makers the ability to 1) identify natural areas in need of immediate conservation, 2) target communities with high flood risk and low ecological services, and 3) develop new polices for instituting green infrastructure and natural conservation approaches within these identified and targeted areas.
• In contrast, the literature review part about the model is too long and contains unnecessary information. The authors are not selling this software; they only need to provide basic information, such as inputs, outputs, and some application worldwide (shorten your paragraphs). We should either merge this section with Introduction or Methods.
• The literature review section has been reduced significantly and the gaps within it highlighted more so to showcase the uniqueness of the research.
• Please provide the study area with a map showing the location of the study area. The list of data input (or main inputs) can be summarized in a table (with data sources). The section 3.1. is not very clear.
• A new study area map has been added as well as a new table of data inputs, years, and sources. Finally, section 3.1 has been rewritten for clarity.
• Are the chosen indices and the weighted factors also applied in other studies?
• Each of these outputs, provided by Co$ting nature, have been used in all of the previously mentioned applications of the model discussed in the literature review, to varying degrees. These are all consistent outputs provide by the model which can then be integrated, combined, or further analyzing using various spatial analytics tools.  This has been clarified in the writing.
• In the introduction, they mentioned the period 2001 – 2017. I am just wondering if the model can help you to provide several snapshots over the period. I am not sure if I miss the information, but I can’t find which year did you use to build the maps?
• The Co$ting Nature data came from 2011 and comes from 1 year increments (will be updated this year) and there is a function within the program that allows the user to project into the future. By using that function, snapshots can be taken over a period of time. This has been stated in the writing.  

Minor comments:

• There is 2.1, but no 2.2.
• Section 2.2. has been added. It was left out in error
• Figure 1: some texts (e.g. legends) are unreadable. Please consider removing them/making them larger.
• All images have been updated for clarity and readability
• Figure 2: in the center of the figure, why there is a straight line which separates the moderate low and moderate region?
• The line is created from patchworking the tiles of data together. It is impossible for the outputs to omit.
• Table 2: should you consider using a pie chart and combine it with Figure 2?
• A pie chart of the percentages has been input into table 2

I hope that my comments can help you to improve the quality of the manuscript.

Reviewer 2 Report

The research focuses on the analysing of ecosystem services provided by natural-based solution using a GIS approach that integrates six types of services

The paper is well set and have good sound
just one request about the weight in the table 1 is not so clear . You give 20% an 5 maps and not value at Relative ecosystem services (ES) relevant risk. It seem that 100% of the value is covered by the 5 maps. maybe you could explane better it

Author Response

Reviewer 2:

The research focuses on the analysing of ecosystem services provided by natural-based solution using a GIS approach that integrates six types of services

The paper is well set and have good sound

just one request about the weight in the table 1 is not so clear . You give 20% and 5 maps and not value at Relative ecosystem services (ES) relevant risk. It seem that 100% of the value is covered by the 5 maps. maybe you could explain better it

• Thank you for the comment. We now see that the write up was somewhat confusing. We have added extra text to clarify this issue and updated the table to assist. Since not all the services in the greatest relative total realized bundled service output, the predominant realized service in each pixel were applicable to this study’s objectives, we extracted carbon, nature-based tourism, water, hazard mitigation, wild-life services, and environmental quality as our primary outputs for analysis. We then reclassified these eco-service maps with an index value range into five categories each. A “1” score indicated the lowest level of service provided (least suitable) while a “5” score signified the highest number of services (most suitable). The hazard mitigation map of relative ES relevant risk was also classified by a similar system where a “1” score denoted a low risk while a “5” score represented a high risk. An equally weighted overlay between all five of the Co$ting Nature eco-service output maps was then ap-plied. Because we treated both risk and NBS are equally important, the weights were uniformly applied to create the suitability model. The equally weighted approach has been routinely applied when conducting similar spatial overlays in the literature and such an approach helps limit biases in the outputs which can come when overly weighting specific variables. Overall, we weighted 5 of the Co$ting Nature outputs at 20% each (relative aggregate nature conservation priority index [potential services], Relative total potential bundled services index, relative aggregate nature conservation priority index [realized services], relative delphic conservation priority index, and greatest relative total realized bundled service), to create a 100% weighting summation, then linked this output with the relative ecosystem services relevant risk output.

Reviewer 3 Report

The Authors has been apply a suitability model to the Co$ting Nature outputs, identifying high flood risk and low ecosystem service areas, in need of immediate NBS to increase resilience.
Very interesting is the discussion about LID practice; in mediterranean areas, in the last decades, the urban and pluvial flood are most frequent (>60% of river flood cases). The authors at the end of the conclusions highlight the criticalities of the model presented. They are aware that NBS techniques alone cannot adapt to all possible environments and need integration with other flood mitigation techniques. Nonetheless, NBS are very versatile conservation strategies at different scales and conditions of use that still need to be strengthened in their diffusion and correct design on an urban scale.

In detail, it should be noted that:
- in lines 6-28 to give a sense of internationality to the paper, it should be pointed out that the problem of flood mitigation also connected to the transformations that coastal areas have undergone due to the rapid growth of tourist interest, involves many territories, especially those of the Mediterranean. In this regard, some should be mentioned such as:

Faccini F.;  Luino L.; Paliaga G.; Roccati A.; Turconi L. Flash Flood Events along the West Mediterranean Coasts: Inundations of Urbanized Areas Conditioned by Anthropic Impacts. Land 2021, 10(6), 620 (https://www.mdpi.com/2073-445X/10/6/620)

López Díez, A.; Máyer Suárez, P.; Díaz Pacheco, J.; Dorta Antequera, P. Rainfall and Flooding in Coastal Tourist Areas of the Canary Islands (Spain). Atmosphere 2019, 10, 809. 

Génova, M.; Máyer, P.; Ballesteros-Cánovas, J.; Rubiales, J.M.; Saz, M.A.; Díez-Herrero, A. Multidisciplinary study of flash floods in the Caldera de Taburiente National Park (Canary Islands, Spain). Catena 2015, 131, 22–34. 

Fragoso, M.; Trigo, R.M.; Pinto, J.G.; Lopes, S.; Lopes, A.; Ulbrich, S.; Magro, C. The 20 February 2010 Madeira flash-floods: Synoptic analysis and extreme rainfall assessment. Nat. Hazards Earth Syst. Sci. 2012, 12, 715–730. 

- Paragraph 3.1 does not provide the type of data used and above all the scale and degree of detail of the same. The reference period of the data is missing. When it comes to the attribution of different weights, which is always a very delicate matter, it is assumed that they are in a range from 1 to 5 (suitable) but this tends to "level" all the risks (eg tourism vs mitigation of the risk). This part should be explored better.
-In figure 2 the coordinates should be entered
-The projects that are directed towards the NBS on an international level should be examined, to give a picture of the new guidelines of "behavior".

Author Response

Reviewer 3:

The Authors has been apply a suitability model to the Co$ting Nature outputs, identifying high flood risk and low ecosystem service areas, in need of immediate NBS to increase resilience.
Very interesting is the discussion about LID practice; in mediterranean areas, in the last decades, the urban and pluvial flood are most frequent (>60% of river flood cases). The authors at the end of the conclusions highlight the criticalities of the model presented. They are aware that NBS techniques alone cannot adapt to all possible environments and need integration with other flood mitigation techniques. Nonetheless, NBS are very versatile conservation strategies at different scales and conditions of use that still need to be strengthened in their diffusion and correct design on an urban scale.

In detail, it should be noted that:
- in lines 6-28 to give a sense of internationality to the paper, it should be pointed out that the problem of flood mitigation also connected to the transformations that coastal areas have undergone due to the rapid growth of tourist interest, involves many territories, especially those of the Mediterranean. In this regard, some should be mentioned such as:

Faccini F.;  Luino L.; Paliaga G.; Roccati A.; Turconi L. Flash Flood Events along the West Mediterranean Coasts: Inundations of Urbanized Areas Conditioned by Anthropic Impacts. Land 2021, 10(6), 620 (https://www.mdpi.com/2073-445X/10/6/620)

López Díez, A.; Máyer Suárez, P.; Díaz Pacheco, J.; Dorta Antequera, P. Rainfall and Flooding in Coastal Tourist Areas of the Canary Islands (Spain). Atmosphere 2019, 10, 809. 

Génova, M.; Máyer, P.; Ballesteros-Cánovas, J.; Rubiales, J.M.; Saz, M.A.; Díez-Herrero, A. Multidisciplinary study of flash floods in the Caldera de Taburiente National Park (Canary Islands, Spain). Catena 2015, 131, 22–34. 

Fragoso, M.; Trigo, R.M.; Pinto, J.G.; Lopes, S.; Lopes, A.; Ulbrich, S.; Magro, C. The 20 February 2010 Madeira flash-floods: Synoptic analysis and extreme rainfall assessment. Nat. Hazards Earth Syst. Sci. 2012, 12, 715–730. 

• An international perspective has been added using case examples and the refences you provided and suggested. Increases in the vast amount of impervious surface impedes water infiltration, in-creases surface stormwater runoff, and causes a greater frequency and intensity of flooding [4]. Such conditions are international issues. For example, many coastal areas in the Mediterranean are suffering from flash flooding problems due to increased urbanization [5]. Further, intense development due to tourism increases in the Canary Archipelago of Spain have resulted in intense negative environmental issues and increased flooding problems [6]. National parks located in Spain’s Canary Islands are being slowly eroded by peripheral development and re-vegetation of efforts within the floodplain have been hampered by torrential floods [7]. Portugal is undergoing similar circum-stances. On the 20th of February of 2010, Portugal’s island of Madeira was hit by torrential rainfall that triggered catastrophic flooding which accounted for 45 deaths; such flooding issues are projected to increase due to lack of green space, increased impervious surfaces, and forecasted climate changes [8].

- Paragraph 3.1 does not provide the type of data used and above all the scale and degree of detail of the same. The reference period of the data is missing. When it comes to the attribution of different weights, which is always a very delicate matter, it is assumed that they are in a range from 1 to 5 (suitable) but this tends to "level" all the risks (eg tourism vs mitigation of the risk). This part should be explored better. The projects that are directed towards the NBS on an international level should be examined, to give a picture of the new guidelines of "behavior".

• hank you for the comment. We now see that the write up was somewhat confusing. We have added extra text to clarify this issue and updated the table to assist. Since not all the services in the greatest relative total realized bundled service output, the predominant realized service in each pixel were applicable to this study’s objectives, we extracted carbon, nature-based tourism, water, hazard mitigation, wild-life services, and environmental quality as our primary outputs for analysis. We then reclassified these eco-service maps with an index value range into five categories each. A “1” score indicated the lowest level of service provided (least suitable) while a “5” score signified the highest number of services (most suitable). The hazard mitigation map of relative ES relevant risk was also classified by a similar system where a “1” score denoted a low risk while a “5” score represented a high risk. An equally weighted overlay between all five of the Co$ting Nature eco-service output maps was then ap-plied. Because we treated both risk and NBS are equally important, the weights were uniformly applied to create the suitability model. The equally weighted approach has been routinely applied when conducting similar spatial overlays in the literature and such an approach helps limit biases in the outputs which can come when overly weighting specific variables. Overall, we weighted 5 of the Co$ting Nature outputs at 20% each (relative aggregate nature conservation priority index [potential services], Relative total potential bundled services index, relative aggregate nature conservation priority index [realized services], relative delphic conservation priority index, and greatest relative total realized bundled service), to create a 100% weighting summation, then linked this output with the relative ecosystem services relevant risk output.

-In figure 2 the coordinates should be entered

• We have added to coordinated into Figure 2

Round 2

Reviewer 1 Report

The manuscript entitled “Combining Co$ting Nature and Suitability Modeling to Identify High flood risk areas in need of nature-based services” submitted to Land journal. The authors applied the Co$ting Nature Models to quantify ecosystem services along the Texas Coast. The revised version has improved significantly compared to the first submission.

Figure 1. add a inset showing the map of the US and the location of the study area?

Table 1. Do you/they have the flood vulnerability map data for 2011?

Figure 2. Please rearrange the locations of the legend.

Figure 3. Could you move the labels upward?

Author Response

Figure 1. add a inset showing the map of the US and the location of the study area?

• The inset map has been added with a locator diagram for the study area

Table 1. Do you/they have the flood vulnerability map data for 2011?

• The Flood vulnerability data was for 2013, not 2010 (as shown). We have corrected this error and double checked all data dates for accuracy

Figure 2. Please rearrange the locations of the legend.

• Locations of legends have been rearranged and linked better to their respective mappings

Figure 3. Could you move the labels upward?

• All labels have been slightly moved to adjust for clarity and readability.