Exposure mapping
Flood and drought layers are intersected with population grids, buildings, roads and utilities to count who and what lies in each hazard class.
The Global Centre for Risk and Innovation (GCRI)
Geospatial methods put every observation on the map: catchment boundaries, flood extents, wells, treatment works and the people and assets exposed to each hazard.
Water NexusWireframe of the working environment, not a live screen. Names and values are placeholders.
Geospatial information systems capture, store, analyse and present location-referenced data. They provide the common spatial frame for combining hazard, exposure and vulnerability information. In water, climate and hazards and critical infrastructure, geospatial analysis identifies where hazards overlap critical assets and vulnerable populations. It supports location-based planning across infrastructure, health and finance. The canonical description is on the STEM Commons.
Flood and drought layers are intersected with population grids, buildings, roads and utilities to count who and what lies in each hazard class.
Elevation models are conditioned and routed to delineate basins and sub-catchments consistently across borders.
Maps are generalised to cells so they can be published without exposing individual wells, intakes or households.
Where this page’s subject sits in the world: boundaries and context now, the field layers when the interactive map loads.
MapWorld map in the Equal Earth projection, land and boundaries from Natural Earth (public domain). The interactive map loads through the Nexus Foundry plugin (globe or flat view).
Data from the source register feeds the methods; calibration and an independent test gate the estimate and its limits; the decision stays with the competent authority.
Fig. 01Nodes carry their type, metrics and state; connectors show what feeds what; the gates are the validation steps; the timeline is one application. Design of the method’s use, not a record of a run.
Datasets and records used by geospatial information systems on this platform, with the role each plays and the label its values carry. Sources are listed in the source register.
| Data | Role | Label |
|---|---|---|
| Digital elevation models | Delineation, routing, inundation | MODELLED |
| Gridded population | Exposure counts | ESTIMATED |
| OpenStreetMap and national asset data | Infrastructure exposure | REPORTED |
| Administrative boundaries | Reporting units | OFFICIAL |
Positional and attribute accuracy are checked against surveyed control points and reference datasets. Topology rules and metadata standards ensure consistency.
| Check | How it is done |
|---|---|
| Projection and alignment | Every layer is reprojected to a common equal-area grid before intersection |
| Normalisation | Counts are reported with their denominators; maps of rates use fixed class breaks across dates |
| Disclosure review | Published cell sizes are checked so no individual asset or household can be identified |
Errors in projection, scale and data currency propagate through analysis. Aggregation to administrative units can mask local variation.
Space and Earth Observation stewards geospatial information systems for the Consortium and reviews how it is applied across platforms.
| Link | Relationship | Why |
|---|---|---|
| Geospatial information systems | Canonical method page | Platform application links to the canonical method page. |
| Geospatial information systems in space and earth observation | Steward platform | Space and Earth Observation stewards this method. |
The current service level is R0: information and enquiries. 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.