Nexus Standards · NS-15 · Proposed
NS-15
NS-15: System model binding (identity levels, passports, chronotopes, relationships, risk routes and engines, cell intelligence, agent genomes)
NS-15 is a proposed Nexus Standard; the artifacts it governs are identified by UNIs (Unique Nexus Identifier). A risk information system describes the world through a system model: subjects, object passports, chronotopes, relationships, risk routes, risk engines, cell-based intelligence (pins and frames over a discrete global grid), agent genomes and risk-context envelopes. NS-15 binds each of these concepts to the Nexus Standards: which UNI category or record kind identifies it, which identity level it may claim, which NS-9 context it belongs to, which NS-10 clauses may bind it and how NS-11 evaluates it. An implementation's own system model remains the authority for its own semantics; NS-15 fixes only how the standards see it, so that every implementation that adopts NS-15 exposes the same model at its interfaces.
Summary
- Statusproposed
- Responsible scopetrust, authorization and assurance; canonical risk data, records and provenance
- Identifier
NXS-STD-ST-000014 - Rules stated0
- Programme areas0
- Source filesrepository
Nexus Standards · proposed
Status of NS-15
Preparatory working draft, circulated for review and comment. Not for implementation. Prepared and circulated by The Secretariat of the Nexus Standards, Global Centre for Risk and Innovation (GCRI Canada) (public@therisk.global), 17 October 2026. Technical review area: TR-02. This document is not a Nexus Standard; it may change without notice and is not to be implemented, relied upon or cited as a Nexus Standard. Its stage is designated only by the Global Standards Council and its technical committees under NS-13. Recipients are invited to submit comments with supporting reasons, and to notify any patent rights of which they are aware. See the notice of circulation.
Hazards and exposure in the Caribbean
The map frames the Caribbean as an example geography for the subject of NS-15; the frame gives context and is not a statement of where the standards apply. Shown at first: flood water, 3-day composite (VIIRS Global Flood Product, NASA LANCE); active fires and thermal anomalies, last day (VIIRS NOAA-20 375 m, FIRMS, NASA LANCE FIRMS); and population density, 2020 (Gridded Population of the World v4.11, NASA SEDAC, CIESIN, Columbia University). The layer drawer adds land surface temperature, day, 8-day composite (VIIRS NOAA-20 Level 3, 8-day); night-time lights, daily (VIIRS Black Marble, VNP46A2); and aerosol optical depth, daily (VIIRS NOAA-20 Deep Blue AOD). NASA products are served through NASA GIBS under NASA's open data policy, with acknowledgement; population density is GPW v4.11 by CIESIN, Columbia University, under CC BY 4.0; coastlines, boundaries and place names come from NASA GIBS reference layers (© OpenStreetMap contributors, ODbL) and Natural Earth (public domain). Each layer shows its own observation date; full credits are given under the map.
The interactive map needs JavaScript; the layer list and sources are below.
Layers 3
Hazards and exposure
Keyboard, with the map focused
Hold Ctrl or ⌘ and scroll to zoom
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.
Flood water, active fires and surface heat beside population and night-time lights, framed on the Caribbean.Satellite and model products as NASA publishes them, each with its own date; indicators, not assessments of any place.
Data: NASA GIBS · ASTER GDEM · Blue Marble · © OpenStreetMap contributors · Natural Earth · NASA EONET · U.S. Geological SurveySources 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
- 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
- NASA Fire Information for Resource Management System (FIRMS), VIIRS 375 m active fire product, NASA LANCE; vector tiles 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
- 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 and VIIRS atmosphere products, NASA LANCE and LAADS DAAC; 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
- © 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: NASA EONET Events are indicative, not authority warnings.
- Live: U.S. Geological Survey Events are indicative, not authority warnings.
- 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).
- Optional layers (8 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
- Flood water, 3-day composite: VIIRS Global Flood Product, NASA LANCE · 14 Oct 2026
- Active fires and thermal anomalies, last day: VIIRS NOAA-20 375 m (FIRMS), NASA LANCE FIRMS · 13 Oct 2026
- Population density, 2020: Population: CIESIN, Columbia University, Gridded Population of the World v4.11 (2018), NASA SEDAC, CC BY 4.0 · static
- Land surface temperature, day, 8-day composite: VIIRS NOAA-20 Level 3, 8-day, NASA LANCE · 14 Sep 2026
- Night-time lights, daily: VIIRS Black Marble (VNP46A2), NASA LAADS DAAC · 12 Oct 2026
- Aerosol optical depth, daily: VIIRS NOAA-20 Deep Blue AOD, NASA LANCE · 13 Oct 2026
NS-15 among the standards.
Fig.The standards on which NS-15 builds, those that cite it and the programme areas where it applies, from the texts and the registry.
The standard as a process
A representation becomes a subject only when it is enrolled at identity level 4 through the record identifier service; the durable passport is filled from records; relationship edges carry evidence and chronotopes; a risk-context envelope requests an evaluation or a route; attestations name the subject by its UNI (Unique Nexus Identifier). 8 operations in 5 phases; each states its actor, its decision rule, the record it leaves and the rule identifiers it implements (17 rules of NS-15 and the standards it applies).
All operations in order (8)
- 01
Representation start · Identity
A rendered feature is a representation of something, not a subject.
- Who
- a map, tile or interface
- Decision rule
- levels 0 to 3 never mint; tile and feature ids are never UNIs
- Record
- a feature at identity level 0 to 3, which never mints
- Implements
- NS15-R1
- 02
Enrol at level 4 gate · Identity
Enrolment allocates the subject UNI; a de-escalation is recorded, never inferred.
- Who
- the responsible steward of the subject, with the receipt the system model requires
- Decision rule
- a level is a recorded fact; escalation needs a receipt or enrollment
- Record
- an SU UNI through the record identifier service
- Implements
- NS15-R1, NS15-R2
- 03
Durable passport record · Passport
A rendered or investigative passport is not durable and carries no UNI of its own; a public-safe projection is a separate version.
- Who
- the governed data service
- Decision rule
- every section is filled from records or marked NOT_AVAILABLE with the reason
- Record
- a passport version with sections filled from records and a limitations section
- Implements
- NS15-R5, NS15-R6, NS15-R7, NS15-R9
- 04
Relationship edges step · Relations
Probability and scenario references are carried where applicable.
- Who
- the data steward
- Decision rule
- a disputed edge is shown as disputed, never dropped
- Record
- edges naming both ends by UNI with evidenceRef and validity
- Implements
- NS15-R11, NS15-R12, NS15-R13
- 05
Chronotope step · Relations
Time and place of validity are explicit, so a result is never read outside them.
- Who
- the data steward
- Decision rule
- evaluations across different chronotopes are INDETERMINATE
- Record
- chronotopeRef on contexts and attestations that depend on time or place
- Implements
- NS15-R14
- 06
Context envelope step · Routing
An envelope without a resolvable subject is refused.
- Who
- the requester
- Decision rule
- the envelope is digested into the evidence of the evaluation or route
- Record
- a risk-context envelope: requester, purpose, subject, space, time, chronotope
- Implements
- NS15-R23, NS15-R24
- 07
Risk route decision · Routing
Engines are selected by their recorded lifecycle state.
- Who
- the trust and assurance system
- Decision rule
- excluded candidates are kept with reasons; a re-route supersedes
- Record
- a route with its policy decision and excluded candidates
- Implements
- NS15-R15, NS15-R16, NS15-R18
- 08
Attest the subject end · Assurance
The passport's policy section lists results as PASS, FAIL, INDETERMINATE, NOT_APPLICABLE or REFUSED.
- Who
- an evaluator with a mandate
- Decision rule
- an attestation on a representation is REFUSED; results are shown as recorded, never as a score
- Record
- an attestation naming the SU UNI or a contextual UNI
- Implements
- NS15-R4, NS15-R8
Fig.Phases read left to right; each card names the operation, its actor and the record it leaves, and each edge label names the hand-over. Play, step or scrub; the detail panel gives the full text of the selected operation. Sources: NS-15: System model binding.
NS-15 clause by clause
11 clauses and 0 rules as stated in the standard, presented with numbered clauses, stable rule anchors, versions and changes.
Identity levels and what each may carry (NS15-R1 to NS15-R4)
The system model defines seven identity levels for a selectable object. NS-15 fixes the identifier each level may carry and the records each level may bear.
| Level | Name | Identifier the level may carry | Records allowed |
|---|---|---|---|
| 0 | transient render pick | none; a render-local handle that is never persisted | none |
| 1 | source-backed representation | the source's own stable id, cited with its source release NXS-GRX-SR-…@v | none |
| 2 | candidate UNI representation | a candidate subject key; never an allocated UNI | none |
| 3 | observed UNI representation resolution | an authority receipt naming an existing subject UNI | none of its own |
| 4 | durable UNI subject | NXS-<SCOPE>-SU[-<REGION>]-<SERIAL> (NS-3 record kind SU), allocated by the record allocation authority on authorized enrolment | corrections (CR) |
| 5 | passport-bound and chronotope-bound subject | the SU UNI, a durable passport (section 2) and a chronotope version NXS-GRX-CT-…@v | passports, chronotopes, contexts (NS-9) |
| 6 | risk-product-bearing subject | the SU UNI and analytical product records NXS-GRX-AP-…@v | risk products, attestations (NS-11) |
- NS15-R1 A UNI shall be allocated to a subject only at level 4 and only through the record allocation authority (NS1-R2, NS-3); levels 0 to 3 never allocate. Vector-tile feature ids,
feature.id,properties.id, tile-local indexes, loop indexes, array positions, geometry ordinals, display labels and nearby names shall not become a UNI or a candidate key. - NS15-R2 A level is a recorded fact, carried as
identityLevelon the passport, and shall not be inferred from presentation. Escalation requires the receipt or enrolment that the level requires; de-escalation (quarantine on an identity conflict) is a correction record (CR), never a deletion. - NS15-R3 A clause (NS-10) shall bind only subjects at level 4 or higher; a policy that names lower levels is invalid.
- NS15-R4 An attestation (NS-11) shall name the subject by its SU UNI, or by an NS-9 contextual UNI whose
context.ofUniresolves to one; an attestation on a representation is REFUSED (reasonSUBJECT_IDENTITY_LEVEL).
Object passports (NS15-R5 to NS15-R9)
The system model defines three passport levels and thirteen standard sections. NS-15 binds them to records.
| Passport level | Nature | Identifier | Record |
|---|---|---|---|
| Rendered representation passport | read-only, transient, source-backed | none; carries the source id and the source release ref | not a record |
| Investigative passport projection | read-only assembly from records | none; carries the UNIs of every record it assembled | not a record; its manifest is a digest |
| Durable object passport | resolved by UNI, authorized by policy, versioned and correctable | the subject's SU UNI; the passport version is the record version @v | NS-3 subject record versions |
The thirteen sections (header and status; identity; location and geometry; classification; relationships; chronotope; data and evidence; dynamic risk state; science and methods; scenarios; policy and reliance; corrections; exports and interoperability) are the information architecture of every passport. NS-15 fixes the standards fields inside them:
| Section | Standards fields |
|---|---|
| Identity | uni (SU), identityLevel, representationRefs (source id and NXS-GRX-SR-…@v), contextUnis (NS-9 DP and PR records whose context.ofUni is this subject) |
| Classification | objectProfileId (section 3), domains and sectors from the registries |
| Relationships | typed edges per section 4, each with the related UNI and the evidence record ref |
| Chronotope | chronotopeManifest = NXS-GRX-CT-…@v |
| Data and evidence | evidenceManifest = record refs <recordUni>@<recordVersion> and digests (NS-3) |
| Dynamic risk state | dynamicRiskStateRef = the ref of the risk-context envelope (section 8) and the latest NXS-GRX-AP-…@v |
| Science and methods | method and model cards as NXS-<SCOPE>-MD-… and engine descriptors (section 6) |
| Policy and reliance | the NS-10 policies bound to the subject (bindings), the latest NS-11 attestation per clause, the conformance level achieved and the policy decision ref |
| Corrections | correctionRefs = NXS-GRX-CR-…@v |
| Exports and interoperability | the NS-3b crosswalks (STAC, DCAT, PROV-O) and the NS-2 citation of the passport version |
- NS15-R5 A durable passport shall exist only for a subject at level 4 or higher; a rendered or investigative passport states
durable: falseand carries no UNI of its own. - NS15-R6 Every section shall be either filled from records or marked
NOT_AVAILABLEwith the reason; no section shall be filled from a display value. - NS15-R7
limitationsis required and shall be non-empty on every durable passport version. - NS15-R8 The policy-and-reliance section shall show attestation results as recorded (PASS, FAIL, INDETERMINATE, NOT_APPLICABLE, REFUSED); it shall not render a score, badge or certificate (NS0-P8).
- NS15-R9 A public-safe projection shall be a separate record version with its own digest; it omits restricted sections and states that it does so.
Object profiles (NS15-R10)
The system model specialises passports through profiles. NS-15 catalogues each profile as a schema artifact (NXS-GRX-SC-…) and fixes the id each subject carries as objectProfileId:
| Profile | objectProfileId | Typical NS-9 contexts |
|---|---|---|
| Building and facility | nexus.profile.building | host-city deployments |
| Road and transport segment | nexus.profile.transport-segment | corridors |
| Business and organisation | nexus.profile.organization | sector programmes |
| Natural feature | nexus.profile.natural-feature | basins, ecosystems |
| Infrastructure asset | nexus.profile.infrastructure-asset | utilities |
| Project | nexus.profile.project | programme instances (PR) |
| Place and administrative area | nexus.profile.place | jurisdictions, M49 areas |
| Sensor and observation system | nexus.profile.sensor | instruments (OPS) |
| Hazard event | nexus.profile.hazard-event | warning events (EWS) |
| Network and supply chain | nexus.profile.network | network continuity (NET) and supply-chain programmes |
- NS15-R10 A profile id is a classification, not a name; a new profile shall be proposed under NS-13 and catalogued before any subject uses it.
Relationship classes and the hypergraph (NS15-R11 to NS15-R13)
The typed relationships of the system model are the edge vocabulary: identity and alias; part-of and contains; occupies and operates; owns (where lawful); located-in and intersects; depends-on and supplies; controls and mitigates; causes and contributes-to; exposed-to; vulnerable-to; observed-by; financed-by; insured-by (where authorized); regulated-by; affects; supersedes; derived-from; contradicts; validates; invalidates. NS-15 fixes:
- NS15-R11 An edge shall name both ends by UNI (SU, DP, PR or a record UNI) and shall carry
evidenceRef(<recordUni>@<recordVersion>),validFromandvalidUntil,directionand, when applicable,probability,scenarioRef,disputed,capacity,threshold,commonCauseRef,substitutesandstate(failure or recovery). A relationship among more than two parties is a hyperedge with an orderedparticipantslist. - NS15-R12
supersedes,derived-from,contradicts,validatesandinvalidatesare the only classes that a standards record (clause, policy, attestation, crosswalk) may use;validatesandinvalidatesedges from an attestation to a subject shall be written by the NS-11 evaluator alone. - NS15-R13 A disputed edge shall be shown as disputed; it shall not be dropped to make a graph consistent (NS0-P8, NS0-P9).
Chronotopes (NS15-R14)
A chronotope version NXS-GRX-CT-…@v is the only record that fixes the time, space, knowledge and situation dimensions of a subject: valid, transaction, observation, acquisition and publication time, forecast issue and valid time, scenario, decision, execution, outcome and correction time; geometry version, spatial support, coordinate reference system and datum, boundary version, jurisdiction, worldview, coverage and resolution, positional uncertainty; source cut, evidence available, ontology version, model version, epistemic state, contradiction and dispute state, correction state; hazard, operational, dependency, control, policy, intervention and scenario state.
- NS15-R14 Every NS-11 attestation and every NS-9 context whose validity depends on time or place shall carry
chronotopeRef; an evaluation over records of different chronotopes is INDETERMINATE (reasonCHRONOTOPE_MISMATCH) unless the clause declares the window that reconciles them.
Risk routes and risk engines (NS15-R15 to NS15-R18)
| System-model object | NS-1 category | Scope | Notes |
|---|---|---|---|
| Risk method, risk model | MD | GRX (or the functional class that owns it) | method and model cards per NS-12 |
| Risk engine descriptor | SW (engine), with engineId as relatedIdentifiers[IsIdenticalTo] | NXQ | lifecycle below |
| Risk pipeline | WF | GRX | |
| Risk route | AP record NXS-GRX-AP-…@v, kind risk-route | GRX | routeUni is the UNI of this record |
| Risk product | AP record, kind risk-product | GRX | |
| Risk capability package | SW, with a nexus-proposal.v1 record for intake | NXQ | packaging interface as declared by the package |
- NS15-R15 The
lifecycleStateof an engine descriptor (DECLARED, SCAFFOLDED, IMPLEMENTED, CONNECTED, EVALUATED, ASSURED, DEPRECATED, QUARANTINED, RECALLED, RETIRED) is a recorded fact. ASSURED requires an NS-11 attestation chain with result PASS on the engine's validation and uncertainty-profile clauses, under a verified mandate. No other state shall be raised by an attestation. - NS15-R16 The
policyDecisionRefof a risk route shall be a recorded policy decision of the implementation's trust authority; itsexcludedCandidatesshall be kept with their exclusion reasons; the route record is append-only, and a re-route supersedes it. - NS15-R17 Numbered placeholder engines and generated wrappers that do not represent a distinct capability shall not be catalogued; a request to catalogue one is refused with
ENGINE_NOT_DISTINCT. - NS15-R18
claimCeilingon every engine, route and product record shall follow the claim registry and shall not exceed INTEGRATED until the registry changes.
Cell-based intelligence (NS15-R19 to NS15-R21)
An implementation may organise intelligence over a discrete global grid (for example H3 cells): pins that mark cells of interest, indicator layers, frames that record a layer over cells at an instant, graphs, edges, runs and jobs. Such an implementation keys these objects by opaque internal identifiers.
- NS15-R19 Opaque internal identifiers of cell-based intelligence shall remain internal keys; they shall not be shown as names and shall not replace a UNI.
- NS15-R20 A pin that is durable and that its owner enrols as a subject shall receive an SU UNI through the record allocation authority and shall keep its internal identifiers as
representationRefs; its cells (for example H3 indexes) are location, not identity. - NS15-R21 A frame is an observation record (OB) of one indicator layer over its cells at
recordedAt; the composite value, its lower and upper bounds andriskStateshall be presented as recorded, and a withheld composite (all values null) shall be shown as withheld.
Agent genomes and risk-context envelopes (NS15-R22 to NS15-R24)
- NS15-R22 An agent genome (a declarative description of an agent with the sections apiVersion, kind, metadata, identity, niche, authority, tools, memory, chronotope, outputs, evaluation and limitations) shall be catalogued as a software artifact
NXS-NXQ-SW-…with the NS-12 obligations. Itsauthoritysection names the mandate the agent acts under; an agent that evaluates a clause (NS-11) is an evaluator whose mandate is verified like any other, never a privileged one. - NS15-R23 A risk-context envelope (requester, purpose, subject kind and UNIs, spatial extent, temporal extent,
chronotopeRef) is the request record of an evaluation or a risk route; it shall be digested into the evidence of the attestation or route, so that the question asked is as citable as the answer. - NS15-R24
subject.kindvalues (UNI, OBJECT, LOCATION, PROCESS, NETWORK, PORTFOLIO, ROUTE, SCENE, POPULATION, SYSTEM, MODEL, TECHNOLOGY) map to object profiles (section 3) or to NS-9 contexts; an envelope without a resolvableuniRefsentry evaluates at identity level 1 to 3 and yields no attestation (NS15-R4).
8a. Identity registries (NS15-R25)
- NS15-R25 An implementation may operate a durable identity registry beside the NS-3 record allocation authority (for example a registry of namespaces, registrations, identity records, versions, acceptance receipts, quarantine events and integrity checkpoints). The two are bound and do not compete: the NS-1 UNI is the only public, citable identifier, and only the record allocation authority allocates it; the identity registry holds the evidence that a subject exists at identity level 4 to 6 (NS15-R1) and records the subject's SU UNI as its canonical key once one is allocated. The identity registry shall not mint an identifier in the NS-1 form, and the record allocation authority shall not store identity evidence. A registry record without an SU UNI is a candidate identity (level 1 to 3) and yields no passport.
Conformance (NS-14)
| Level | Requirements |
|---|---|
| NS-15 Basic | R1, R2, R5, R6, R7, R19 |
| NS-15 Standard | Basic, and R3, R4, R8, R11, R14, R15, R22 |
| NS-15 Full | Standard, and every remaining rule (including R25) |
An implementation declares its level in registry/consumers.yaml. The declaration is SELF_DECLARED until NS-11 attestations under a verified mandate raise it to VERIFIED.
Record schema
schemas/nexus-subject-passport.v1.json is the standards envelope of a durable passport: the fields NS-15 fixes in section 2, the identity level, the profile id, the relationship edges (section 4) and the policy-and-reliance block. An implementation's own passport contract remains authoritative for everything else; the schema validates the envelope, not the science.
Open items
- NS15-O1: whether SU UNIs for durable pins are allocated under
GRXor under the functional class that owns the context in which the pin is used. - NS15-O2: the signing arrangement that turns a VERIFIED engine assurance into ATTESTED (NS-10 section 3).
- NS15-O3: a crosswalk of the relationship classes to W3C PROV-O and to the OGC GeoSPARQL and CityGML relation vocabularies (an NS-14 register entry).
Changes between versions
One published version is available (0.1.0); a comparison between versions is shown once a second version is published.
Clause numbers follow the sections of the document; rule identifiers () are stable anchors. With script enabled, each clause and rule has a permalink and a machine-readable view (YAML and JSON), and the j and k keys move between clauses.
System model and cascade scenario: NS-15 System model binding
A system model of the context of NS-15 built from the registry: 26 hazards, 17 systems, 10 sectors, 14 controls, 23 feeds, 17 indicators. The systems are no area lists NS-15; the areas of the NRS core and nexus-stream series, the systems it binds; the model shows where the records, data and controls that NS-15 governs sit in a cascade, and is not a reading of the standard's text. Select the components to include, choose an initiating hazard and run the scenario. Stress propagates through the hazard relations of the Nexus Hazard Standard (NHS-1), the exposure of each system, the recorded couplings and the sectors that carry the loss; adopted standards dampen transmission and live data sources support detection. All parameters are stated assumptions that the reader can adjust; results are illustrative scenario outputs for exercises and training, not forecasts or risk assessments. The Map view places the same run on an example geography, Bangladesh, a region suited to the hazards named, with open data: Natural Earth boundaries, an H3 hexagon grid and NASA satellite layers for the initiating hazard. The geography serves exercises and training and is not an assessment of that place.
Hazards
- Natech event
- Heatwave
- Windstorm
- Dam failure
- Financial contagion
- Ice-jam flood
- HIV epidemic
- Antimicrobial resistance
- Flash flood
- Meteorological drought
- Groundwater depletion
- Widespread power outage (set off downstream)
- Large forest disturbance (set off downstream)
- Wildfire (set off downstream)
- Extreme fire weather (set off downstream)
- Heat-driven grid stress (set off downstream)
- Agricultural drought (set off downstream)
- Flash drought (set off downstream)
- Snow drought (set off downstream)
- Ground-level ozone episode (set off downstream)
- Debris flow (set off downstream)
- Hydrological drought (set off downstream)
- Peat and underground fire (set off downstream)
- Forest dieback (set off downstream)
- Water supply shortfall (set off downstream)
- Acute food crisis (set off downstream)
Systems and couplings
- Compound and cascading hazard standards
- Energy risk standards
- Global and systemic risk
- Food and agriculture risk standards
- Health risk standards
- Water risk standards
- Hydrometeorological hazard standards Compounding
- Geophysical hazard standards Triggering
- Critical infrastructure and critical entities Cascade
- Climate risk standards Feedback
- Space weather, spectrum and timing risk standards Common driver
- Financial stability and prudential risk Mechanism
- Supply chain and trade risk Cascade
- Future generations and long-term risk Common driver
- Conflict and security risk standards Feedback
- Biological hazard standards Cascade
- Atmosphere and air quality risk standards Common driver
Controls
NS-0Constitution and principlesNS-3Risk record UNIs (grammar, legacy crosswalk, allocation authority)NS-9Contextual UNIs (deployments, instances, programme instances)NS-11Verification and monitoring (evidence, attestations, zero-trust conformance observation)NS-1The UNI and the artifact catalog (grammar v0.2: domain, sector, region and environment segments)NS-10Policies and clauses (machine-readable obligations: definition, binding, evaluation and enforcement)NS-14Conformance and crosswalk to external standardsNS-3bDataset and product metadata profile (STAC, DCAT, PROV-O)NRS-H61Hazard family: Cascading failure (NHS-1 sys.cascade)NRS-H62Hazard family: Compound and multi-hazard events (NHS-1 sys.compound)NRS-H60Hazard family: Supply-chain and flow disruption (NHS-1 sys.supply-chain)NRS-H48Hazard family: Utility and communication network outage (NHS-1 infra.utilities)NRS-H84Hazard family: Energy system instability and shortfall (NHS-1 infra.energy)NRS-H94Hazard family: Systemic cyber events (NHS-1 cyber.systemic-cyber)
Observation
- Copernicus EMS rapid mapping activations (listed for reference)
- OpenStreetMap planet and replication (listed for reference)
- ERA5 reanalysis (Copernicus Climate Data Store) (listed for reference)
- Global Power Plant Database (listed for reference)
- NASA Black Marble night-time lights (VNP46) (listed for reference)
- Ember electricity data (listed for reference)
- ENTSO-E Transparency Platform (listed for reference)
- EIA Open Data API (listed for reference)
- INFORM Risk Index (listed for reference)
- World Bank Open Data and World Development Indicators API (listed for reference)
- IMF data services (WEO, IFS, FSI via SDMX) (listed for reference)
- IPC acute food insecurity analyses (listed for reference)
- FEWS NET outlooks and data (listed for reference)
- CHIRPS quasi-global gridded precipitation (listed for reference)
- FAO GIEWS Food Price Monitoring and Analysis tool (listed for reference)
- ESA WorldCover 10 m land cover (listed for reference)
- WHO Disease Outbreak News (listed for reference)
- WAHIS animal health events (listed for reference)
- WorldPop gridded population (listed for reference)
- USGS Water Data APIs (listed for reference)
- GloFAS global flood forecasts and reanalysis (listed for reference)
- GRACE/GRACE-FO terrestrial water storage mascons (listed for reference)
- Aqueduct 4.0 Water Risk Atlas (listed for reference)
- Direct economic loss attributed to disasters in relation to global GDP
- Number of disruptions to basic services attributed to disasters
- Proportion of population with access to electricity
- Renewable energy share in total final energy consumption
- Damage to critical infrastructure attributed to disasters
- Macroeconomic Dashboard
- Prevalence of undernourishment
- Prevalence of moderate or severe food insecurity (FIES)
- Indicator of food price anomalies
- Direct agricultural loss attributed to disasters
- International Health Regulations capacity and health emergency preparedness
- Mortality rate attributed to household and ambient air pollution
- Number of deaths and missing persons attributed to disasters per 100,000 population
- Number of destroyed or damaged health facilities attributed to disasters
- Level of water stress: freshwater withdrawal as a proportion of available freshwater resources
- Proportion of transboundary basin area with an operational arrangement for water cooperation
- Proportion of population using safely managed drinking water services
Example geography
- Bangladesh: 134 H3 hexagons at resolution 4
- Night lights tonight, outages (VIIRS Day/Night Band), NASA GIBS
- Surface air temperature, daytime (AIRS), NASA GIBS
- Rain rate, last half hour (IMERG), NASA GIBS
- Surface water through cloud, 30 m (OPERA DSWx-S1 radar), NASA GIBS
Recent research on NS-15
Recent peer-reviewed articles, preprints, datasets and reports on the subject of this standard, retrieved at the time of reading from open scholarly metadata services (OpenAlex, Crossref, DataCite, Zenodo, arXiv, Europe PMC, OpenAIRE Graph) with search terms composed from the registry. Each work is listed with its authors, venue, year, type, open-access status and licence, and links to its DOI or landing page. Sources not yet enabled for live display on this site are listed for reference and are not queried.
Search termsdigital twin; systemic risk model; socio-technical system; system of systems; complex adaptive systems; Sendai Framework Monitor; UNDRR-ISC Hazard Information Profilescombined with: risk; resilience; infrastructure; model; modellingDerived from the subject of the standard and its rules, and the external standards of its crosswalk domains.
- OpenAlexlisted for reference; not queried
- Crossreflisted for reference; not queried
- DataCitelisted for reference; not queried
- Zenodolisted for reference; not queried
- arXivlisted for reference; not queried
- Europe PMClisted for reference; not queried
- OpenAIRE Graphlisted for reference; not queried
No source is enabled for live display on this site yet: the sources are listed for reference and none is queried. Once the publisher of record enables a source after its terms are reviewed, recent works are listed here. Metadata and links only: title, authors, venue, year, type, open-access status and licence as each source records them; works are listed for orientation, not reviewed or endorsed.
NS-15 in the standards repository
The text, schemas, machine-readable files, registry rows, tests and history behind NS-15, on the main branch of the canonical repository. Text, registry, schemas and catalog are CC BY 4.0; tools and tests are Apache-2.0.
Source text
| File | What it holds | Links |
|---|---|---|
standards/NS-15-system-model-binding.md | NXS-STD-ST-000014 | Raw · History · Suggest an edit |
standards/INDEX.md | status and document of every standard | History |
Schemas
| File | What it holds | Links |
|---|---|---|
schemas/nexus-subject-passport.v1.json | Nexus subject passport envelope (NS-15) | Raw |
Machine-readable files
| File | What it holds | Links |
|---|---|---|
catalog/artifact-catalog.yaml | catalog records · 3 mentions | First mention, line 557 |
Registry rows
| File | What it holds | Links |
|---|---|---|
registry/review-investigations.yaml | Circulation for technical review and comment, and the technical review areas · 2 rows or mentions | Line 58 |
registry/consumers.yaml | Register of implementations of the Nexus Standards · 1 row or mentions | Line 20 |
registry/dags.yaml | Process and pipeline graphs rendered by the site's DAG component (nxs-dag) · 1 row or mentions | Line 270 |
registry/open-standards-stack.yaml | Open-standards and open-source stack under the UNI · 1 row or mentions | Line 102 |
registry/standard-packages.yaml | Standard packages - one package per external open standard on nexustandards.com · 1 row or mentions | Line 181 |
Tests and validators
| File | What it holds | Links |
|---|---|---|
tools/validate.mjs | tool or validator | Line 150 |
Change history
| File | What it holds | Links |
|---|---|---|
| Commits to the text | every change to the text | · |
CHANGELOG.md | notable changes, by version | · |
release/manifest.json | release manifest with file digests | in-toto statement |
| Releases | tagged releases of the repository | · |
Propose a change
| File | What it holds | Links |
|---|---|---|
| Open a proposal on NS-15 | issue form: target, kind, rationale (NS-13) | Template |
| Issue form: comment | issue form | Template |
| Issue form: errata | issue form | Template |
| Issues that mention NS-15 | open and closed | · |
| Pull request template | what a change must carry: target, kind, rationale, validation | · |
CONTRIBUTING.md | pull requests, sign-off and checks | · |
GOVERNANCE.md | how registry codes and texts change | · |
How NS-15 is developed, and how to take part
NS-15 is developed in the open under NS-13 (the stages and gates of NS-13). Working groups draft, councils decide the reserved matters, and anyone may propose a change, comment, submit an implementation report, object or appeal, without membership or fee.
- Who decides what: the decision-rights matrix.
- The process: stages, gates, review windows and appeals.
- Open gateways and calls: how to propose, comment, join a working group or request activation.
- Develop a standard: the development track and the lifecycle of each standard.
- NS-13 in the canonical repository.
Relation to external standards
NS-15 relates to external standards by identifier, clause number and URL (NS14-R1), and directs the reader to the issuing body.
Recent research and sources
Peer-reviewed articles, preprints, reports and datasets on the subject of this standard, retrieved at the time of reading from open scholarly metadata services (OpenAlex and Crossref) and listed with authors, venue, year, type and access status, with a link to each work. Curated references and related standards are listed first; recent works matched by subject follow and are listed for orientation.
Related standards and frameworks
- UNDRR-ISC Hazard Information Profiles (HIPs)
UNDRR and International Science Council - IEC 62443 series Security for industrial automation and control systems
IEC TC 65 with ISA (ISA/IEC 62443) - ISO 55000:2024 Asset management - Vocabulary, overview and principles
ISO/TC 251 - WMO Cataloguing of Hazardous Events (WMO-CHE)
WMO (adopted by Congress 2019) - Sendai Framework Monitor (38 indicators)
UNDRR - INFORM Risk Index - Concept and Methodology
European Commission Joint Research Centre with the Inter-Agency Standing Committee - Sendai Framework for Disaster Risk Reduction 2015-2030
UN Member States (Third UN World Conference on DRR); UNDRR custodian - ISO 10218 Robotics - Safety requirements for industrial robots
ISO/TC 299
Search terms, derived from the subject of the standard and its rules: digital twin; systemic risk model; socio-technical system; system of systems; complex adaptive systems; combined with: risk; resilience; infrastructure; model; modelling. With JavaScript enabled, recent works matching these terms are listed from OpenAlex and Crossref.
Risk Academy courses and disciplines
2 courses and 2 disciplines of Risk Academy (risksacademy.com) that teach the knowledge and methods of NS-15. Each course lists its level, stream and learning hours.
Courses
Disciplines
The correspondence between courses, disciplines and the Nexus Standards is maintained with Risk Academy and is subject to its academic review.
Programmes, tracks and courses for this standard
GCRI Canada and Risk Academy work on the subject of NS-15 in distinct roles (research and evidence; education and training). Each entry states why it corresponds and the step it offers; each institution sets its own terms of participation.
Research and evidence
GCRI Canada
Research programmes that produce the observations, models and assessments these records describe.
Systems Science and ModellingDevelops coupled-systems modelling and digital-twin methods.Apply to this programme therisk.globalAll programmes of GCRI CanadaEducation and training
Risk Academy
Courses and disciplines that teach the knowledge and methods practitioners need to apply these standards.
Complexity and NetworksRAS-401 · Intermediate · 25.5 learning hoursSeeing systemic risk through feedback, interdependence and network structureTake this course Shock PropagationRAS-403 · Intermediate · 27.5 learning hoursHow cascading and compound shocks travel through supply chains, finance and the Earth system, and how to contain themTake this course All courses and disciplinesListed in the education and training section of this pageQuestions and answers.
What is the status of NS-15?
What does applying NS-15 establish?
How is a change to NS-15 proposed?
Contribute to Nexus Reports from this page.
Nexus 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.
- GatewayGW-STDSend it from this pageEvidence, a correction, a case, a method, a review, a translation or profile input. It arrives tagged with this page, so the editor who owns it receives it.
- ZenodoOpen depositDeposit it and submit to the communityPublish your own record on Zenodo with your ORCID iD, then submit it to the Nexus Reports community. Curators review it there; the DOI stays yours.
- Nexus ReportsGCRISee every way to contributeThe contribution types, how each is reviewed, what credit you receive, the licence and what is never accepted.
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 same subject across the Consortium.
- GCRI Canadatherisk.globalDigital identity for registriesMethods, data and models
- GRFglobalriskforum.comDigital and data governanceMandates, commitments and accountability
- GRAglobalriskalliance.comData and disclosureExposure, loss and capital
- Risk Academyrisksacademy.comRisk data governance, provenance and licensingWhere it is taught
- Nexus Reportstherisk.globalData and Compute in Nexus ReportsWhere it is reported
Around the Nexus Standards.
Take part in the standards.
Governments, regulators, standards bodies, industry, academia and communities are invited to shape the catalogue ahead of its first official release, targeted for 2030: comment on a draft, propose a change, join a working group or host a field exercise.
Status and use. The Nexus Standards are proposed standards developed through an open process under NS-13 and published for voluntary use; they do not constitute certification, accreditation or regulatory approval, and adoption remains a decision of the Global Standards Council and, in each country, of its National Standards Council. A UNI (Unique Nexus Identifier) identifies an artifact; it does not certify it. Names of standards bodies and their standards belong to their stewards and are used only to identify the documents; no text of an external standard is reproduced here. Nexus Standards is not affiliated with, endorsed by or certified by any standards body named here.
Licences: CC BY 4.0 for standards text, registries, schemas and data; Apache-2.0 for reference code. External standards are cited by name, number and link under their own licences. Third-party data, libraries and fonts keep their own licences: see Third-party notices.