G-P16 · TOPIC · urban-social-vulnerabilityGCRI dossier · service level R0
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Topic dossier · Society and Human Development

Urban social vulnerability

In cities, hazards strike people unequally. Low-income residents, renters, migrants, older people, people with disabilities and those in informal settlements often face more exposure and have fewer resources to cope and recover. This page sets out how social vulnerability arises in cities, how it is measured and mapped, and what evidence serves the city governments and agencies that plan for it.

01In brief

The short answer.

Urban social vulnerability is the greater susceptibility of some city residents to harm from hazards, arising from where they live, the resources they have and whether institutions see them. Exposure follows affordability, coping capacity differs, some groups are invisible to registers and recovery can widen gaps.

02Geography

Urban signals in Latin America and the Caribbean.

For urban social vulnerability, in GCRI's spatial-intelligence reading, the map opens on population density, true-colour imagery and night lights, framed on Latin America and the Caribbean; every other NASA layer, live feed and forecast waits in the layer list.

The interactive map needs JavaScript; the layer list and sources are below.

Layers 3

Urban signals, for this page

Latest available

NASA GIBS / EOSDIS · ASTER GDEM (METI, NASA) · Blue Marble (NASA) · © OpenStreetMap contributors (ODbL) · Natural Earth

Loading the latest NASA imagery.

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.

For urban social vulnerability, in GCRI's spatial-intelligence reading, the map opens on population density, true-colour imagery and night lights, framed on Latin America and the Caribbean; every other NASA layer, live feed and forecast waits in the layer list.Satellite and model products as NASA publishes them, each with its own date; indicators, not assessments of any place; claim ceiling INTEGRATED.

Data: NASA GIBS · ASTER GDEM · Blue Marble · © OpenStreetMap contributors · Natural Earth · GDACS · USGS · Copernicus Sentinel-2 L2ASources and licences

  • 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
  • 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). CC BY 4.0
  • 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
  • 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
  • MODIS land products (vegetation indices, gross primary production, land cover), NASA LP DAAC and 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). NASA open data
  • Made with Natural Earth. Free vector and raster map data @ naturalearthdata.com. Public domain
  • © OpenStreetMap contributors (ODbL), via NASA GIBS (coastlines, boundaries, roads and place names). Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). ODbL
  • 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
  • Context on the globe and flat map: coastlines, boundaries, roads and place names from NASA GIBS reference layers (OpenStreetMap data, ODbL, © OpenStreetMap contributors); Blue Marble imagery as an optional base; 3D terrain and the elevation read-out from the ASTER GDEM elevation colour index (5 m to 200 m classes, exaggerated for legibility). Boundaries are drawn as published and imply no position on any territory.
  • Globe: MapLibre GL JS 6.9.1, BSD-3-Clause, © MapLibre contributors.
  • Live: GDACS (EC JRC / UN OCHA) Events are indicative, not official warnings.
  • Live: USGS Events are indicative, not official warnings.
  • Observed (EO): Copernicus Sentinel-2 L2A (contains modified Copernicus Sentinel data 2026), Microsoft Planetary Computer
  • Optional layers (35 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

  • Population density, 2020: Population: CIESIN, Columbia University, Gridded Population of the World v4.11 (2018), NASA SEDAC, CC BY 4.0 · static
  • True colour: VIIRS NOAA-20 corrected reflectance, NASA LANCE · 13 Oct 2026
  • Night-time lights, daily: VIIRS Black Marble (VNP46A2), NASA LAADS DAAC · 12 Oct 2026
  • Land cover type (IGBP), yearly: MODIS Terra and Aqua land cover (MCD12Q1), NASA LP DAAC · 2024
  • Flood water, 3-day composite: VIIRS Global Flood Product, NASA LANCE · 14 Oct 2026
  • Enhanced vegetation index, rolling 8 days: MODIS Terra EVI, NASA LANCE · 13 Oct 2026

03Console

Humanitarian needs overview, in outline.

The working screen behind this subject: its structure, terms and states. Names are placeholders and values illustrative.

Humanitarian needs overview: the screen's structure, terms and states for Urban social vulnerability.Placeholder names and illustrative values; a design, not a record or a live system.
04The question

Urban social vulnerability: how the risk develops.

Community resilience and informal services. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.

Mechanism

Exposure follows affordability

Cheaper housing is often in flood zones, near industry or in hotter neighbourhoods, so low-income residents face more hazard.

Mechanism

Coping capacity differs

Savings, insurance, social networks, mobility and language skills shape how people prepare for and recover from shocks.

Mechanism

Some groups are invisible

Undocumented migrants, homeless people and informal workers may be missed by registers and warnings and avoid official help.

Mechanism

Recovery widens gaps

Owners with insurance rebuild while renters are displaced, so recovery can deepen inequality in a city.

05Key terms

Terms used on this page.

Each term as this page uses it. Where a standard-setting body defines the term, the wording follows that body.

TermDefinition
Coping capacityThe ability of people and organizations to manage adverse conditions using available resources.
Social vulnerability indexA composite measure combining social variables to compare vulnerability between areas.
Tenure insecurityLack of protection against eviction from one's home or land.
06Indicators

What is measured, and how well.

Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.

IndicatorUnitCadenceSource typeLabel
Population in hazard zones by income grouppeopleper assessmentCensus and hazard overlaysESTIMATED
Households without insurancepercent of householdsper surveyHousehold surveysREPORTED
Older people living alonecountper censusCensusOFFICIAL
Renters as share of householdspercentper censusCensusOFFICIAL
Language barriers to warningspercent of residents with limited official languageper censusCensusOFFICIAL
Homelessnesspeople counted by a stated definitionper countAdministrative countsREPORTED
07Canvas

From sources to decisions.

The topic as a computational graph: named sources feed the methods, an evidence review gates the outputs, and the decisions stay with the authorities that hold them.

Pipeline canvas · Urban social vulnerability as a run graphDesign, not a record
Urban social vulnerability: asset register to adaptation optionsThe asset register is overlaid on hazard layers to find exposure; vulnerability classes turn exposure into expected damage; assets are ranked and adaptation options costed into the capital plan. Design of the process, not a record of a run.

Fig. 02Nodes carry their type, two metric rows and a state; connectors show what feeds what; dashed frames name the owners; the timeline is the cadence. Design of the pipeline, not a record of a run.

08Sources

Where the evidence comes from.

Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.

SourceWhat it givesLicence class
National censuses and small-area statisticsPopulation characteristics by neighbourhoodLicence per statistics office
CDC/ATSDR Social Vulnerability Index documentationA published method for combining census variables, for method referencePublic domain, US government
Household surveys with urban samplesAssets, insurance and copingLicence per survey
Local hazard mapsFlood, heat and other hazard zonesLicence per authority
UN-Habitat urban dataUrban inequality and housing indicatorsPublic, UN-Habitat terms (to check)
09Decisions

Who decides, and what the evidence serves.

Society and Human Development prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.

Who decidesThe questionEvidence this page serves
City governmentsWhere to target preparedness, outreach and recovery supportVulnerability maps; equity reviews
Emergency managersHow to reach groups missed by standard warningsOutreach gap analyses
Housing authoritiesHow to protect renters and low-income residents in recoveryRecovery equity evidence

Outputs this topic produces

  • Neighbourhood social vulnerability maps with uncertainty
  • Equity reviews of emergency plans and recovery
  • Outreach gap analyses for warnings and services
  • Evidence notes for city resilience strategies
10Core questions

The questions experts ask.

  • Who lives in the most hazardous parts of a city, and why?
  • How do informal services perform during shocks, and who relies on them?
  • How does insecure tenure affect investment in safety and recovery?
  • Which community institutions sustain resilience, and how can they be supported?
  • How do heat, flooding and service failure interact in dense neighbourhoods?
11Mechanisms

Informality, density and exposure.

Informal settlements often occupy land left undeveloped because it is hazardous: floodplains, steep slopes, coastal margins or land near industrial sites. Dense housing with little green space intensifies urban heat, and poor drainage turns rain into flooding. Insecure tenure discourages households from investing in safer housing and can exclude them from formal recovery support.

Informal providers, such as water vendors, informal transport and savings groups, fill service gaps and can be flexible in crises, but they may also raise prices or fail when supply chains break. Community networks and organizations are central to everyday resilience, sharing information, resources and labour. Evictions and relocation after disasters can destroy these networks and livelihoods.

Urban heat illustrates how these factors combine. Dense, poorly ventilated housing, lack of shade and green space, outdoor work, unreliable power and limited access to cooling or health care mean that the same heatwave can be far more dangerous in an informal neighbourhood than in a planned district nearby.

12Methods and data

Methods and limits.

Mapping

Community mapping

Participatory and imagery-based mapping of settlements and services; official maps often omit informal areas.

Surveys

Neighbourhood surveys

Household and community surveys of exposure, services and tenure.

Spatial

Vulnerability indices

Spatial indices combine indicators; results depend on weighting choices.

Limits: informal areas are under-counted in censuses, vulnerability indices can hide the specific drivers that matter locally, and publishing detailed maps of settlements can expose residents to eviction.

13Methods

How it is studied, and what the methods cannot say.

14Questions

Questions and answers.

What is social vulnerability?
The characteristics of people and communities that affect their capacity to anticipate, cope with, resist and recover from hazards.
How is social vulnerability mapped?
By combining census and survey variables such as income, age, disability, housing and language into indicators for small areas, with stated weights and uncertainty.
Why do some groups recover more slowly?
Because they have fewer savings, less insurance, insecure tenure or less access to assistance, so the same shock sets them back further.
Does the platform publish maps of informal settlements?
Only where residents and data owners agree and a public-safe review confirms that publication will not expose them to harm.
Are informal services part of the analysis?
Yes. They are often critical lifelines and are studied alongside formal services.
Does the platform work directly with communities?
Participatory research opens with authorized projects, ethical review and consent.
Society and Human Development

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