The Global Centre for Risk and Innovation (GCRI)
Infrastructure systems depend on each other: power runs water pumps and telecommunications, telecommunications control the grid, fuel needs both, and all need transport and staff. A failure in one can cascade into others, and restoration must follow the same dependencies. This page sets out how interdependencies arise and cascade, how they are mapped and modelled, and what evidence serves those who plan for multi-system failure.
GCRI · In development · service level R0
Infrastructure interdependency is the relationship by which the state of one infrastructure system affects others, through physical, cyber, geographic or logical links. It lets a failure in power, communications or transport cascade into other lifelines, and it makes restoration depend on the same links.
For interdependency and cascade, in GCRI's spatial-intelligence reading, the map opens on night lights, true-colour imagery and population density, framed on Western Europe; 3 further NASA layers wait in the list.
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Layers 3
Infrastructure exposure, for this page
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NASA GIBS / EOSDIS · ASTER GDEM (METI, NASA) · Blue Marble (NASA) · © OpenStreetMap contributors (ODbL) · Natural Earth
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For interdependency and cascade, in GCRI's spatial-intelligence reading, the map opens on night lights, true-colour imagery and population density, framed on Western Europe; 3 further NASA layers wait in the list.Satellite and model products as NASA publishes them, each with its own date; indicators, not assessments of any place; claim ceiling INTEGRATED.
Layers and dates
Shared failure points and restoration sequence. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
One system needs a physical output of another, as pumps need electricity and generators need fuel. When the supply stops, the dependent system stops once its buffer runs out.
Control systems, billing and coordination depend on data networks. Communications failure can stop operations even when physical equipment is undamaged.
Systems share corridors, bridges, tunnels and sites. One flood, fire or earthquake damages several at once, removing the redundancy that separate systems seemed to offer.
Repairing power needs communications and road access; restoring communications needs power. Restoration plans that ignore these loops stall.
Each term as this page uses it. Where a standard-setting body defines the term, the wording follows that body.
| Term | Definition |
|---|---|
| Physical dependency | A dependency in which one system needs a material output of another, such as electricity. |
| Geographic dependency | Exposure of several systems to the same local event because they share a location. |
| Infrastructure stress test | An analysis that applies hazard scenarios to mapped systems to see which services fail and for how long. |
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.
| Indicator | Unit | Cadence | Source type | Label |
|---|---|---|---|---|
| Mapped interdependencies between sectors | count of documented dependencies | annual | Dependency inventories | DECLARED |
| Co-located critical assets | count of sites hosting several sectors | per assessment | Geospatial analysis | ESTIMATED |
| Buffer time by dependency | hours | per asset class | Operator continuity data | DECLARED |
| Services affected per initiating failure | count of dependent services | per scenario | Interdependency models | MODELLED |
| Joint restoration exercises held | count | annual | Exercise records | REPORTED |
| Multi-sector incidents | count of incidents affecting more than one sector | annual | Incident databases | REPORTED |
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.
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.
Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.
| Source | What it gives | Licence class |
|---|---|---|
| UNDRR Principles for Resilient Infrastructure and stress test methodology | Approach for national infrastructure stress testing | Public, UN terms of use |
| CDRI Global Infrastructure Resilience report | Cross-sector infrastructure risk analysis | Public, terms to check |
| National critical infrastructure strategies and sector plans | Sector definitions and dependency analyses | Public records, licence per government |
| Post-event reports on multi-system failures | Documented cascades across lifelines | Public records, terms per publisher |
| OpenStreetMap infrastructure layers | Locations of power, water, telecom and transport assets | Open, ODbL |
Critical Infrastructure prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| Who decides | The question | Evidence this page serves |
|---|---|---|
| National critical infrastructure coordinators | Which interdependencies need joint planning and oversight | Dependency maps; cascade scenarios |
| Sector operators | Which upstream dependencies to secure with backup or contracts | Buffer times; co-location analyses |
| Emergency management agencies | How to coordinate restoration across sectors | Joint restoration studies; exercise results |
Research on interdependent networks has shown that coupling can make systems more fragile than either would be alone: a small failure in one network can trigger disproportionate failure in another. Real cascades combine physical, cyber, geographic and logical dependencies, described on dependencies and consequences. Time is critical: many dependencies are buffered by storage or backup, so cascades often unfold in waves as each buffer is exhausted.
Restoration has its own dependency structure. Power restoration needs communications and access; communications restoration needs power; road clearance needs fuel. Without coordination, operators can each wait for the others. Restoration science therefore treats recovery as a scheduling problem across systems, with limited crews, parts and fuel.
Systemic risk in a broader sense is studied at Systemic Risk Management.
Coupled network models from network science and contagion explore how failures propagate between systems.
Agent-based and input-output models from systems engineering represent operators, buffers and timing.
Scheduling methods from optimization and operations research explore restoration orders under resource constraints.
Cascade models are sensitive to dependency data that is often missing or confidential. Abstract network models can overstate or understate fragility, and real behaviour depends on human decisions in the moment.
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.