The influence of Covid-19 Pandemic and Climate Change on Water Use and Supply: Experiences of Istanbul and London Area

01/06/2022

Response to Editor’s and Reviewers’ Comments

We thank the reviewers and the editor for their helpful comments regarding our paper retitled “The influence of Covid-19 Pandemic and Climate Change on Water Use and Supply: Experiences of Istanbul and London Area”, and we have reviewed the comments and revised the paper accordingly. As the paper has been revised thoroughly (structure as well) in the light of all the helpful comments of reviewers and editor, changes are not highlighted in the revised paper, and we have given the details of changes for each comment below.

Editor (Dr Pam Berry)

The topic of  water usage during Covid-19 and impacts of climate change is important and current, thus the article is timely. However, as it stands at version 1 it is rather descriptive; there is no clear indication of exactly how some methods were undertaken (e.g. the last paragraph of p6 in the pdf). Also, some more /different analysis would help support or clarify some of the arguments. For example:

1. Fig. 8 links higher temperatures to low reservoir levels, despite having established a link for reservoir levels with rainfall, so are temperature and rainfall correlated? This is important when examining scenarios and also when deciphering what is driving reservoir levels – most likely an interaction of climate and socio-economics and demography

Rainfall anomaly has been added. Interaction with temperature, rainfall and reservoir levels, and other factors (socio-economic) have been discussed.

2. The different patterns of domestic and business water usage is important. It would be helpful, if possible to separate these out in total consumption figures.

During the data collection from the responsible organizations, it was not possible to get sector-based water consumption data due to municipality’s privacy.

3. Careful reasoning is also need in emergent issues, as p22 suggest more periods of dry weather and yet p14 it is only RCP8.6 in the latter part of the century that is projected to be drier.

More periods of rainfall and temperature projections have been added with different scenarios and uploaded to UCL Data Respiratory. We have retained sections on emergent and strategic issues that arise directly from our studies but recognize that these need to be dealt with in more detail in due course.

4. Discussion (especially the first part) would benefit from synthesis round key arguments and findings.

Discussion section has been improved accordingly, and strategic and emerging issues have been added to the discussion in more detail.

5. All in all I think this paper needs a more analytical approach, framed round certain arguments and hypotheses.

Paper has been revised according to all comments, and methodology and other sub-headings has been added in order to provide a more analytical approach that has used mixed methods incorporating both quantitative as well as qualitative data. We hope the additional material on the DPSIR Framework is beginning to identify where arguments and hypotheses could be developed for specific aspects of adaptive management plan.

Reviewer 1 (Osman Zeybek)

1. Weather conditions and climate change are two different things. There is a big misconception in the article about these two subjects. Weather condition is the atmospheric conditions that comprise the state of the atmosphere in terms of temperature, wind, clouds, precipitation, which is very temporary and unstable. But climate is the average weather in a place over many years. Climate change is a shift in those average conditions, that is accelerated in recent years due to environmental problems.

In order to avoid such misunderstandings, paper has been revised by clearly defining these terms.

2. The introduction begins with the importance of water and water management, which is good. Climate change must be defined and explained along with its effect on the water circle. Pandemic and climate change have to be discussed more about their origins and related effects on settlements. Some research claims that pandemic is also a result of climate change. Make sense of the connection between. So, the title of the article should be "The Impacts of Covid-19 Pandemic & Climate Change on Water Environment: The Case of Istanbul and London."

The title has changed accordingly. “The influence of Covid-19 Pandemic and Climate Change on Water Use and Supply: Experiences of Istanbul and London Area”

3. Towards the end of the introduction, some unclear sentences appear. In line 117, "... unexpected situations such as the Covid-19..." What else? Every situation that is examined must be written here. In the line 118-119, specify the dates that data compiled. "previous years" is not a certain phrase. In lines 121-122, is there an implication for Covid-19 lockdown? Which lockdown? When? These paragraphs should be rewritten clearly.

Changes have been made accordingly.

4. DPSIR is abbreviated for what? Explain the methodology.

Abbreviation of DPSIR and methodology section have been added.

5. In the figures, there are some graphics shared with meaningful data compiled from related authorities (some of them are not cited). In order to make sense of the metadata, this information should be selected between the exact dates. Istanbul's water consumption is between 2000-2020, but population and water consumption are between 2000-2019. The water reservoir level is between 2000-2021, etc. (?)

All data is referenced in the methods section, which now has more consistent time frames. We have updated our data sets (now up to March 2022).

6. Since this is a comparison article, the same data should be shared and interpreted for London, too. And before this, it should be explained why these two cities were chosen as case studies. What are the common and comparable features?

Study area section has been added in methodology.

Reviewer 2 (Volkan Müftüoğlu)

The article is highly original in that it is the first time a DPSIR framework has been used to study the effects of Covid-19 and climate change on water consumption.

1. Some parts of the article are written too long. A shorter and simpler narrative style will be correct in terms of attracting the reader's attention.

Some paragraphs (especially in discussion) have been shortened. Table 1 including “the main findings of how countries have been affected by different phases of the pandemic with sources and main comments related to the final DPSIR framework” has been added.

2. Due to one of the sample areas of the article is Istanbul, it would be more accurate to replace the municipality of Bolu street disinfection photo in Figure 5 with a photo from Istanbul.

Disinfection photo from Istanbul has been added.

Reviewer 3 (Tom van der Voorn)

The authors present a paper, in which they examined how unexpected situations such as the Covid-19 pandemic might affect water usage and availability. Although the paper is well-written and well-structured, I do have some concerns about the paper, which merit further attention.

1. My first comment relates to the usage of the DPSIR framework. I agree with authors that the application of the DPSIR framework for signaling differences in water consumption patterns during the pandemic. Since climate change and covid-19 are two different drivers (van der Voorn et al, 2020) which manifest themselves at different time scales, including their impacts, there lies a major challenge in obtaining some separate evidence that the pandemic restrictions affected human activity in Istanbul for which they examined air quality parameters, and these suggest air pollution in Istanbul was lower in 2020 than in 2019 indicating decreased human activity consistent with Covid-19 restrictions. However, in order to distinguish between the impacts of these two drivers, I believe the current set of indicators is not sufficient and therefore, I have two suggestions for improvement:

As we try to define how covid and weather-related changes have an impact on water environment, looking at the details of climate and covid relationship will be another research topic. However, we have looked at the below comments and revised paper accordingly.

2. In order to provide more evidence on “waste”, the authors could consider Wastewater-Based Epidemiology, which could be especially informative given that asymptomatic and oligosymptomatic infections are unlikely to be detected during clinical surveillance  see e.g., Bivins et al (2020) and Bhattacharya et al (2021)

Thank you for the comment although we have touched on wastewater discharges, we cannot address any epidemiology aspects of this as we are not gathering information of this kind during the study. This issue may be explored further in later paper dealing with emergent strategic issues.

3. Since people were in lockdown, they may have ordered products and services online. This would increase (slightly) traffic patterns and at least demand for transportation, which in turn increase CO2 emissions.

Figure 17 (Monthly total number of vehicles) and its explanation “decreased number of vehicles measured on one of the main roads in Istanbul after many governmental restrictions (e.g., fully lockdowns) were applied from early April 2020” has been added.

4. In addition, looking at the different time scales to be considered, the DPSIR framework depicted in Figure 1 seems to be a static representation of its DPSIR components. So, in light of the research objective, a more dynamic representation would be required to capture the dynamics across different time scales.

As we mentioned in the paper, Figure 4 only shows the overview of the factors likely to be involved in changing water consumption before going into deeper analyses. Figure 16 is the enhanced version and set out at the next level of detail the factors that may be affected by both climate change and the pandemic, and it shows the factors we believe may need to be considered in developing future resilient water systems and management approaches.

5. My second concern relates to the comparability of the Turkish case with other cases. In my opinion, there are indeed limited comparisons possible, if not impossible between Istanbul and other countries at present due to lack of data availability, as the authors stated. However, it is not just because of a lack of data but also different national characteristics in terms of socio-ecological, socio-economic, socio-technical, and governance aspects. Hence, it requires a solid framework for comparison, which accounts for these differences and similarities, to make any statements on comparability. These aspects could be interpreted as coping capacities. Van der Voorn and de Jong et al (2021) developed a framework for such a comparative analysis.

Some other factors have been added to comprehend why there is limited comparisons in the context of data availability and national characteristics.

6. My final concern relates to the need for new management plans. This would require adaptive management methodologies like for example the Backcasting Adaptive Management methodology (van der Voorn et al, 2012, 2017) or a comprehensive multi-target backcasting approach (van der Voorn et al 2020), which combines the strengths of multicriteria analysis, nexus approaches and backcasting, for supporting a transition to zero GHG emissions The former methodology can help decision makers to develop robust adaptive management plans, whereas the latter allows them to conduct a qualitative environmental assessment of scenarios to identify conflicts and synergies in regard to a broad range of environmental targets (e.g., reduction of biodiversity loss, viable habitats for flora and fauna). I would like to encourage the authors to elaborate on how these methodologies could expand the DPSIR framework in light of the research objective of the paper.

In this study, we looked for evidence of the influence of such factors on water resources and water consumption to provide more detailed framework for thinking through what kind of influences on water supply and consumption patterns needed to be incorporated into future adaptive water management planning for this, and other, major urban centres: therefore, the need for management plans (back casting or comprehensive approaches) would be another research topic in the development of new plans.