Skip to content

GCRI · Science and methods

Geospatial science

Almost every risk question has a where: where hazards strike, where people and assets are, where services reach, where dependencies run. Geospatial science joins Earth observation, geographic information systems (GIS) and spatial statistics to answer it. The Global Centre for Risk and Innovation (GCRI) states the limits too: coordinate systems, scale, data gaps and boundaries that change a result. Part of science and methods.

Make an enquiry Back to Science and methods
01Contents

Geospatial science in seven parts.

In this dossier7 parts
  1. 01MethodsThe geospatial toolkit
  2. 02Units and reference systemsThe reference systems and units that make spatial risk results comparable
  3. 03Spatial validationWhy spatial models need spatial cross-validation
  4. 04GCRI’s partInteroperable spatial evidence, with national geography kept national
  5. 05LimitationsWhere geospatial results can mislead
  6. 06PracticeHow GCRI keeps spatial work checkable
  7. 07RelatedConnected pages
02Methods

The geospatial toolkit.

Geospatial work combines observation, mapping and statistics. Each method has its own assumptions, and results are reported with the choices made.

GIS

Mapping and overlay

Combining hazard, exposure and service layers with geospatial information systems.

Statistics

Spatial patterns

Clustering, interpolation and spatial dependence with spatial statistics and geostatistics.

Access

Networks and reach

Travel time to hospitals, shelters and markets over real road and transport networks.

03Geography

Earth observation worldwide.

Land cover and vegetation across the world, from NASA GIBS. Each layer carries its own date.

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

Layers 2

Earth observation, for this page

About this layer
Evidence
Observed
Source
VIIRS NOAA-20 corrected reflectance (NASA LANCE)
Provider
NASA LANCE
Licence
NASA open data
Vintage
daily; Satellite image
Newest at build
2026-10-14
Resolution
about 250 m grid
Uncertainty
Satellite image. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Modelled (latest year GIBS publishes)
Source
MODIS Terra and Aqua land cover (MCD12Q1) (NASA LP DAAC)
Provider
NASA LP DAAC
Licence
NASA open data
Vintage
yearly; Satellite classification; latest year GIBS publishes
Newest at build
2024-01-01
Resolution
about 500 m grid
Uncertainty
Satellite land cover classes for the year shown, including croplands; a classification with known errors, not a farm register.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Observed (clouds leave gaps)
Source
MODIS Terra EVI (NASA LANCE)
Provider
NASA LANCE
Licence
NASA open data
Vintage
daily; Satellite index; clouds leave gaps
Newest at build
2026-10-13
Resolution
about 250 m grid
Uncertainty
Satellite vegetation index for the 8 days to the date shown, a habitat condition indicator; not a measure of species or biodiversity.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Observed (clouds leave gaps)
Source
MODIS Terra NDVI (NASA LANCE)
Provider
NASA LANCE
Licence
NASA open data
Vintage
daily; Satellite index; clouds leave gaps
Newest at build
2026-10-13
Resolution
about 250 m grid
Uncertainty
Satellite greenness index over the 8 days to the date shown; an indicator of crop and pasture condition, not a yield estimate or a food security warning.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Observed (clouds and night leave gaps)
Source
VIIRS NOAA-20 NDSI (NASA LANCE)
Provider
NASA LANCE
Licence
NASA open data
Vintage
daily; Satellite detection; clouds and night leave gaps
Newest at build
2026-10-14
Resolution
about 500 m grid
Uncertainty
Satellite detection; clouds and night leave gaps. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Observed
Source
GHRSST MUR (NASA JPL PO.DAAC)
Provider
NASA JPL PO.DAAC
Licence
NASA open data
Vintage
daily; Satellite analysis
Newest at build
2026-10-12
Resolution
about 1 km grid
Uncertainty
Satellite analysis. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map

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.

Earth observation, framed on the world.Satellite and model products as NASA publishes them, each with its own date. They are indicators, not assessments of any place.

Data: NASA GIBS · ASTER GDEM · Blue Marble · © OpenStreetMap contributors · Natural Earth · NASA EONET · NASA JPL OPERA DIST-ALERTSources 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 hexagonal 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 hexagonal 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 hexagonal 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 hexagonal cells where shown (modified). NASA open data
  • GHRSST Level 4 MUR analyses, NASA Jet Propulsion Laboratory; distributed by the NASA Physical Oceanography DAAC (PO.DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal 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 hexagonal 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
  • © OpenStreetMap contributors (ODbL), via NASA GIBS (coastlines, boundaries, roads and place names). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). ODbL
  • Blue Marble, NASA Earth Observatory; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal 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.
  • Live events: NASA Earth Observatory Natural Event Tracker (EONET); events are indicative and keep their original source links.
  • Live: NASA EONET Events are indicative, not authority warnings.
  • Observed (EO): NASA JPL OPERA DIST-ALERT (contains modified Copernicus Sentinel data 2026). 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).
  • 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).
  • 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 (11 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

  • True colour: VIIRS NOAA-20 corrected reflectance, NASA LANCE · 13 Oct 2026
  • Land cover type (IGBP), yearly: MODIS Terra and Aqua land cover (MCD12Q1), NASA LP DAAC · 2024
  • Enhanced vegetation index, rolling 8 days: MODIS Terra EVI, NASA LANCE · 13 Oct 2026
  • Vegetation greenness (NDVI), rolling 8 days: MODIS Terra NDVI, NASA LANCE · 13 Oct 2026
  • Snow cover: VIIRS NOAA-20 NDSI, NASA LANCE · 13 Oct 2026
  • Sea ice concentration: GHRSST MUR, NASA JPL PO.DAAC · 12 Oct 2026

04Units and reference systems

The reference systems and units that make spatial risk results comparable.

ElementPracticeWhy it matters
Coordinate reference systemStated by its EPSG code; distances and areas computed in an equal-area or local projected systemAreas computed in geographic degrees are wrong away from the equator
ResolutionGrid cell size in metres or arc-seconds, and the scale of the sourceA coarse population grid smears exposure across a floodplain edge
Vertical datumHeights tied to a named datum and geoid modelFlood and sea-level work fails silently when datums differ by decimetres
Units of analysisAdministrative areas, catchments, hexagonal grids or networks, chosen for the questionThe modifiable areal unit problem (Openshaw, 1984): results change with the zoning
AccuracyPositional and thematic accuracy reported against reference dataA map without accuracy is a picture, not evidence
05Spatial validation

Why spatial models need spatial cross-validation.

Nearby places resemble each other, so a model tested on points close to its training points looks better than it is. Roberts and colleagues showed in 2017 that blocked cross-validation, which holds out whole regions, gives a more honest estimate of how a model will perform in a place it has not seen. The same applies to building-footprint extraction, crop maps and flood susceptibility models.

  • Hold out blocks or whole administrative units, not random points.
  • Report accuracy per region and per class, not only overall accuracy.
  • State where the model should not be used: outside the range of its training conditions.
06GCRI’s part

Interoperable spatial evidence, with national geography kept national.

GCRI follows the UN Integrated Geospatial Information Framework, under which national geospatial agencies hold authoritative boundaries and base data. It uses Open Geospatial Consortium standards so layers move between systems. GCRI maps are research products; legal boundaries and authoritative base maps remain with national authorities. Geospatial datasets would carry ISO 19115 and NS-3b metadata under the proposed Nexus Standards, and released layers feed the Country Systems Risk and Resilience series. Contributions that help: corrections to base data in places maps miss, local field validation and reference samples for accuracy checks.

07Limitations

Where geospatial results can mislead.

Maps persuade easily, which is why their limits are stated beside them.

  • Scale and aggregation: the same data grouped into different areas can show different patterns
  • Boundaries: administrative units rarely match watersheds, grids or labour markets
  • Distance is not access: straight-line buffers can misstate how far people really are from services
  • Data gaps: informal settlements, rural areas and recent change are often missing from base maps
  • Interpolation: surfaces built from sparse samples carry uncertainty that must be shown
08Practice

How GCRI keeps spatial work checkable.

  1. 01

    State the coordinate reference system

    So layers align and distances are correct.

  2. 02

    Test sensitivity to scale

    Results are checked at more than one level of aggregation.

  3. 03

    Validate spatially

    Models are tested on places they were not trained on.

  4. 04

    Respect sensitivity

    Restricted infrastructure locations and protected community sites are never published.

10Sources

Where this page’s references lead.

The bodies and documents this page is read against. Status and editions change; each link goes to the issuing body.

11Questions

Questions and answers.

Do GCRI maps replace the maps of mandated agencies?
No. GCRI maps are research products with their sources and uncertainty. Maps and boundaries for legal use are issued by the competent national authorities.
How are boundaries shown?
Using recognised sources with their names stated. A boundary on a GCRI map implies no position on any territorial question.
Can I get GIS layers?
Released, rights-cleared layers are listed under public data and datasets, with their licence and lineage.
Why does scale matter so much?
Because averages over large areas can hide local extremes, and different groupings can change apparent patterns. Results are tested at more than one scale.
Can communities contribute local mapping?
Yes, through consent-aware routes. Local knowledge can correct gaps in base maps, and protected sites or knowledge are never published without the agreement of the rights-holders.
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.

GCRI

Never send personal data, sensitive infrastructure detail or anything you have no right to share. A contribution is reviewed before use; sending it confers no authorship or editorial rights, and sponsorship never buys a finding.

The Global Centre for Risk and Innovation

Bring a method, a dataset or a question.

Information and enquiries are open today. An enquiry receives a reference and names the next step; applications, payments, compute allocations and registrations open only when their team, terms and review capacity exist.

Propose a method See all contact routes
Legal

Maps, data and figures on this site are shown for context and general information. They are not advice, forecasts or warnings; the limits of the information are set out in the Disclaimers and Data Notices.

Privacy choices