Illustrative: a block model of a city with water rising and falling through its streets, a heat island over its core, or the city growing
Risk Academy, led by the Nexus Consortium · Infrastructure, Energy and Industry · Department of Cities and Infrastructure Systems
Taught in the Nexus stream
Cities, housing and the built environment
The discipline covers how urban form, buildings, housing, mobility and services concentrate exposure, and how planning, design and municipal governance reduce it.
Search any place or open the world; the layers and generators follow cities, housing and the built environment on the planet map, the globe and in 3D.
Infrastructure, Energy and IndustryAny placeTwin builder
The boundaries, names and designations shown do not imply any judgement on the legal status of any territory, or any endorsement or acceptance of such boundaries. Countries: Natural Earth (public domain).
03Live map
Urban signals in India
Night-time lights, population density, nitrogen dioxide and urban heat, over India.
The interactive map needs JavaScript; the layer list and sources are below.
Drag to move. Ctrl or ⌘ and scroll, pinch or the buttons to zoom; hover for the values under the pointer; reset returns to the region.
Urban signals, framed on India.Satellite and model products as NASA publishes them, each with its own date. They are indicators, not assessments of any place.
We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
VIIRS Black Marble night-time lights, NASA Goddard Space Flight Center; distributed by the NASA Level-1 and Atmosphere Archive and Distribution System (LAADS DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
Center for International Earth Science Information Network (CIESIN), Columbia University. 2018. Gridded Population of the World, Version 4 (GPWv4): Population Density, Revision 11. NASA Socioeconomic Data and Applications Center (SEDAC). Licensed under CC BY 4.0. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). doi:10.7927/H49C6VHW. CC BY 4.0
OMI nitrogen dioxide (Aura) and OMPS aerosol index (Suomi NPP), NASA; distributed by the NASA GES DISC; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
VIIRS near-real-time products (flood, land surface temperature, snow cover, corrected reflectance), NASA LANCE; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
ASTER GDEM is a product of METI and NASA (ASTER Global Digital Elevation Model V003, NASA LP DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). Cite as: NASA/METI/AIST/Japan Spacesystems and U.S./Japan ASTER Science Team (2019). ASTER Global Digital Elevation Model V003. doi:10.5067/ASTER/ASTGTM.003. NASA open data
Made with Natural Earth. Free vector and raster map data @ naturalearthdata.com. Public domain
Blue Marble, NASA Earth Observatory; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
Live events: NASA Earth Observatory Natural Event Tracker (EONET); events are indicative and keep their original source links.
NASA GIBS: We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS).
Air quality forecast, 5 days, PM2.5 (CAMS via Open-Meteo): Contains modified Copernicus Atmosphere Monitoring Service information 2026.
Past year, daily temperature and sunshine (NASA POWER): These data were obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program..
Weather data by Open-Meteo.com (https://open-meteo.com/), licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/).
Optional layers (14 sources in the layer list: live, forecast, observed and context) print their provider credit on the map and here when switched on; forecasts are model output and derived indices are estimates.
Layers and dates
Night-time lights, daily: VIIRS Black Marble (VNP46A2), NASA LAADS DAAC · 12 Oct 2026
Population density, 2020: Population: CIESIN, Columbia University, Gridded Population of the World v4.11 (2018), NASA SEDAC, CC BY 4.0 · static
Nitrogen dioxide, lower atmosphere column: OMI Aura, NASA GES DISC · 10 Oct 2026
Land surface temperature, day, 8-day composite: VIIRS NOAA-20 Level 3, 8-day, NASA LANCE · 14 Sep 2026
Flood water, 3-day composite: VIIRS Global Flood Product, NASA LANCE · 14 Oct 2026
04The subject
The subject, methods and measures and debates and bodies
The field and its scope
For planners, municipal engineers, housing officers, insurers and developers who need to measure how urban form and building stock concentrate exposure and to weigh codes, retrofit and land-use choices against each other.
Quantities and units
Methods and their limits
Each method is listed with what it assumes and where it fails.
What the field debates
Bodies that set practice, and the data they publish
Bodies and standards are named so learners can find and apply their published work; the Academy teaches their use and links to the publisher, and no affiliation is implied.
05The method
From ground shaking to a retrofit decision: fragility curves and the benefit-cost ratio
A fragility curve turns the intensity a building stock receives into a probability of damage; multiplied by the stock's count and replacement value it gives an expected loss; a retrofit shifts the curve, and the avoided loss divided by the retrofit cost is the ratio the decision rests on.
Sources: Kircher, Whitman and Holmes, HAZUS earthquake loss estimation methods (2006); Silva et al., Development of a global seismic risk model (2020); Hallegatte, Rentschler and Rozenberg, Lifelines: The Resilient Infrastructure Opportunity (2019); Hallegatte et al., Future flood losses in major coastal cities (2013).
06Instrument
Cities, housing and the built environment
Cities, housing and the built environment at a glance
Open, 1
In preparation, 2
Also taught here, 1
Subtopics, 9
Course codes from the curriculum; study levels L1 to L4.
Risk Academy · Infrastructure, Energy and Industry
07Signature
How cities, housing and the built environment connects the sectors
Select corners to build a signature, then hover a line to read what each sector gives and receives.
Select corners · hover lines6 / 15 relations
Context
Infrastructure and its partners
Infrastructure gives pipes, dams and treatment works to water (0.6), transmission and fuel logistics to energy (0.6) and access to care to health (0.5).
W · E · I · F · H · B
Sectors
4 of 6
Relations
6 of 15
Coupling
0.46 share of total
Strongest relations in play
Energy → Infrastructure · power for transport and telecoms0.8
Water → Energy · cooling water and hydropower0.6
Infrastructure → Water · pipes, dams and treatment works0.6
Water → Health · drinking water and sanitation0.7
Teaching values for a typical city-region, not measurements for any place. Coupling is the summed strength of the relations in play, as a share of all fifteen.
08Standards and evidence
Standards and evidence, research and evidence, profile, what is changing and learning
Nexus Standards it teaches and relies on
The Nexus Standards the discipline teaches toward, grouped by master standard, with the disciplines that teach each.
Nexus Standards at the AcademyThe Academy proposes how each discipline teaches toward the Nexus Standards; the mapping is open for public review.
Research and tools
Research and preprints as they are published, by discipline, with the faculty's other tools.
The hub lists the newest research and preprints for Cities, housing and the built environment, each with its source and date. Open the research hub
Methods, frameworks and hazards
From the Academy's risk taxonomy: the discipline's own entries and those of its primary courses, with how many courses teach each.
Hazard families
Coastal flood and storm surge2 courses
Flash and pluvial flood2 courses
Critical infrastructure outage1 course
Earthquake1 course
Epidemic and pandemic disease1 course
Extreme heat1 course
What is changing now
Recent developments in cities, housing and the built environment, each with its source; sources checked on 16 October 2026.
Courses in this discipline
Courses with this as their primary discipline.
Courses from connected disciplines that also teach this field
Each course has its primary discipline elsewhere and teaches this field as part of its scope.
From connected disciplinesIn preparation
RAT-209Exposure and Vulnerability DataIn preparationTechnical, L2 Intermediate, 10 hours (estimate), primary discipline: Catastrophe, exposure and vulnerability modelling
How the subject is practised in labs
09Console
How Cities, housing and the built environment is taught, as a process you can run
Press Play to run this process from this page's own data.
10Practice
Practice, learning and connections
How technology helps and what risk it brings
Achievements in this discipline
Pathways that teach it
Where the subject is practised
The Global Centre for Risk and Innovation (GCRI Canada)Cities and Built EnvironmentBuildings and heat, Green blue infrastructure, Housing and affordability, Informal settlements, Municipal governance interface, Transport and mobility, Urban growth and land, Urban utilities
Foundry system pages describe what each system and its rooms are designed to do; the courses teach the methods these systems apply.
Disciplines it depends on
Across the ecosystem
11Take part
Take part in Infrastructure, Energy and Industry
Start from who you are.
12References
Core references and where to begin
Start with Pelling, then Silva, then Kircher.
13Questions
Questions, answers and key terms
Is study here free?
Yes. Every course and learning material of Risk Academy, led by the Nexus Consortium, is free to study, self-paced or with a cohort. Ordinary participation has no fee; paid work, internships and fellowships are separate arrangements.
What does completing a course give me?
A completion record: the course, its version, the date and what was assessed, private by default and shared by you. It stacks into discipline, department and programme achievements. A record states what was studied and assessed and does not certify competence; it is not a licence, a professional title or an employment status.
Where do the data and the places come from?
Every faculty teaches on a twin of a real place built from open data; each layer carries its provider, licence and date, and every result on the Academy states its source. Maps and figures are indicators for teaching, never an assessment of a place.
How do I take part beyond the courses in cities, housing and the built environment?
Form a competence cell of three to seven people, study a shared pathway, take a supervised assignment in the National Working Groups, or bring a cohort from your institution. For organisations.
Key terms
Term
Urban heat island
The higher temperatures of built-up areas compared with their surroundings.
Term
Informal settlement
A residential area built without formal land rights or planning approval, often with limited services.
Term
Building code
Rules that set minimum standards for the design and construction of buildings.
Term
Green-blue infrastructure
Networks of vegetation and water features that provide drainage, cooling and other services.
ReportsContribute
Contribute evidence from this page.
Reports is the Consortium's quarterly publication. What you know about this subject can become evidence, a case or a correction in the next edition, credited to you and published under CC BY 4.0 where it is your own work.
Risk Academy
Related
Around Cities, housing and the built environment
Cities, housing and the built environment
Start with an open course
The catalogue lists each course with its outcomes, labs, hours and level.
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Independence
Editors and the expert reviewers named on each article decide what we publish. Funders and partners do not review or approve articles before publication.
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