Crowded Cities: New Methodology in COVID-19 Risk Assessment
Abstract
:1. Introduction
2. Untangling Crowding and Density
- First, population densities decline with incomes, as countries move across stages of economic development. Kinshasa, Mumbai, and Karachi are four to five times more densely populated than Shanghai, Tokyo, or London.
- Second, naïve measures of population density can conflate crowding with livable densities. Kinshasa, Mumbai, and Hong Kong are three cities with similar population densities but very different levels of income.
- 12 m digital elevation and radar intensity data from the German TanDEM-X satellite mission.
- 10 m multispectral Sentinel-2 imagery.
- The human settlement mask of the World Settlement Footprint 2015 (WSF 2015).
- Where available, vector data for building location—for example, data from the Open Street Map initiative.
3. Crowding and COVID-19 Contagion Risk
3.1. Methodology
- The practical inability for keeping people apart, based on a combination of population density and livable floor space that does not allow for 2 m of physical distancing.
- Conditions where, even under lockdown, people might have little option but to cluster (e.g., to access public toilets and water pumps/standpipes).
- First, we use the WorldPop population 2019 raster (see https://www.worldpop.org/ for details on WorldPop data and methodology.) These rasters contain the estimated number of people that live in each pixel, with a resolution of 100 × 100 m. While we used global population datasets, the analysis can be easily adjusted if local sources are available. Population data from local sources may be more accurate than a global population raster. Some cities have developed spatial datasets at considerably high levels of disaggregation, although generally not at the pixel level. The challenge lies in creating a population grid based on these datasets, which usually implies modeling that assigns population to pixels, based on land use and built-up areas. The German Aerospace Center (DLR) has developed a model to generate population grid datasets based on spatially disaggregated population data.
- The second dataset is a layer with the location of key services, such as water kiosks and public toilets, obtained from the Open Street Maps Platform (OSM) (© OpenStreetMap contributors). A schematic outlining the approach is shown in Figure 4.
3.2. Application of the Methodology
3.2.1. Kinshasa, DRC
3.2.2. Dhaka, Bangladesh
3.2.3. Freetown, Sierra Leone
4. Looking Forward—From Crowding to (Livable) Density
4.1. Access to Land, Land Use Planning, and Development Regulations
4.2. Financing
4.3. Concluding Remarks
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
- Ahlfeldt, G.M.; Pietrostefani, E. The Economic Effects of Density: A Synthesis; International Trade and Regional Economics (DP13440); Centre for Economic Policy Research, London School of Economics and Political Science: London, UK, 2019. [Google Scholar]
- Duranton, G.; Diego, P. The Economics of Urban Density. J. Econ. Perspect. 2020, 34, 3–26. [Google Scholar] [CrossRef]
- Lall, S.; Lebrand, M.; Soppelsa, M. The Evolution of City Form: Evidence from Satellite Data; World Bank Policy Research Working Paper 9618; World Bank: Washington, DC, USA, 2021. [Google Scholar]
- Lall, S.; Vernon Henderson, J.; Anthony, J.V. Africa’s Cities: Opening Doors to the World; World Bank: Washington, DC, USA, 2017. [Google Scholar]
- United Nations. Millennium Development Goals Indicators. Indicator 7.10 Proportion of Urban Population Living in Slums. 2015. Available online: http://mdgs.un.org/unsd/mdg/seriesdetail.aspx?srid=710 (accessed on 21 May 2021).
- World Bank. Measuring Living Standards within Cities. Households Surveys: Dar es Salaam and Durban; World Bank: Washington, DC, USA, 2015. [Google Scholar]
- World Bank. Côte d’Ivoire Urbanization Review. Diversified Urbanization; World Bank: Washington, DC, USA, 2015. [Google Scholar]
- Lall, S.; Wahba, S. No Urban Myth: Building Inclusive and Sustainable Cities in the Pandemic Recovery. 2020. Available online: https://www.worldbank.org/en/news/immersive-story/2020/06/18/no-urban-myth-building-inclusive-and-sustainable-cities-in-the-pandemic-recovery (accessed on 12 May 2021).
- Esch, T.; Zeidler, J.; Palacios-Lopez, D.; Marconcini, M.; Roth, A.; Mönks, M.; Leutner, B.; Brzoska, E.; Metz-Marconcini, A.; Bachofer, F.; et al. Towards a Large-Scale 3D Modeling of the Built Environment—Joint Analysis of TanDEM-X, Sentinel-2 and Open Street Map Data. Remote. Sens. 2020, 12, 2391. [Google Scholar] [CrossRef]
- Marconcini, M.; Metz-Marconcini, A.; Üreyen, S.; Palacios-Lopez, D.; Hanke, W.; Bachofer, F.; Zeidler, J.; Esch, T.; Gorelick, N.; Kakarla, A.; et al. Outlining where humans live, the World Settlement Footprint 2015. Sci. Data 2020, 7, 1–14. [Google Scholar] [CrossRef] [PubMed]
- Angel, S.; Lamson-Hall, P.; Blanco, Z.G. Anatomy of density: Measurable factors that constitute urban density. Build. Cities 2021, 2, 264–282. [Google Scholar] [CrossRef]
- Bhardwaj, G.; Esch, T.; Lall, S.V.; Marconcini, M.; Soppelsa, M.E.; Wahba, S. Cities, Crowding, and the Coronavirus: Predicting Contagion Risk Hotspots; World Bank: Washington, DC, USA, 2020. [Google Scholar]
- Davis Donald, R.; Weinstein David, E. Market access, economic geography and comparative advantage: An empirical test. J. Int. Econ. 2003, 59, 1–23. [Google Scholar] [CrossRef]
- Harris, C.D. The market as a factor in the localization of industry in the United States. Ann. Assoc. Am. Geogr. 1954, 44, 315–348. [Google Scholar]
- Head, K.; Mayer, T. The Empirics of Agglomeration and Trade, ch 59; Vernon Henderson, J., Jacques-François, T., Eds.; Handbook of Regional and Urban Economics; Elsevier: Amsterdam, The Netherlands, 2004; Volume 4, pp. 2609–2669. [Google Scholar]
- World Bank. Freetown Urban Sector Review: Options for Growth and Resilience; World Bank: Washington, DC, USA, 2018. [Google Scholar]
- Global Land Tool Network. Access to Land and Tenure Security. Available online: https://gltn.net/access-to-land-and-tenure-security/ (accessed on 20 February 2021).
- United Nations. Goal 11. Sustainable Cities and Communities. Make Cities and Human Settlements Inclusive, Safe, Resilient and Sustainable. 2019. Available online: https://unstats.un.org/sdgs/report/2019/goal-11/ (accessed on 20 February 2021).
- Prindex. Press Release: Almost 1 Billion People Worldwide Expect to Lose Their Homes against Their Will, Prindex Global Study Reveals. 2018. Available online: https://www.prindex.net/news-and-stories/press-release-almost-1-billion-people-worldwide-expect-lose-their-homes-against-their-will-prindex-global-study-reveals/ (accessed on 20 February 2021).
- Cities Alliance. Paul Romer: Cities Need to Make Room. 2020. Available online: https://www.citiesalliance.org/newsroom/news/cities-alliance-news/paul-romer-cities-need-make-room (accessed on 12 May 2021).
- Smolka, M. Assessing the monetary relevance of land value capture: The case for charges for additional building rights in São Paulo, Brazil; Lincoln Institute for Land Policy: Cambridge, MA, USA, 2018. [Google Scholar]
- World Bank. Toward Great Dhaka: A New Urban Development Paradigm Eastward; World Bank: Washington, DC, USA, 2018. [Google Scholar]
- United Nations. Water and Urbanization. Available online: https://www.unwater.org/water-facts/urbanization/ (accessed on 20 February 2021).
- Klein, M. Infrastructure Policy: Basic Design Options; Policy Research Working Paper No.6274; World Bank: Washington, DC, USA, 2012. [Google Scholar]
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
Lall, S.V.; Wahba, S.N. Crowded Cities: New Methodology in COVID-19 Risk Assessment. Sustainability 2021, 13, 7167. https://doi.org/10.3390/su13137167
Lall SV, Wahba SN. Crowded Cities: New Methodology in COVID-19 Risk Assessment. Sustainability. 2021; 13(13):7167. https://doi.org/10.3390/su13137167
Chicago/Turabian StyleLall, Somik V., and Sameh N. Wahba. 2021. "Crowded Cities: New Methodology in COVID-19 Risk Assessment" Sustainability 13, no. 13: 7167. https://doi.org/10.3390/su13137167