- South Asia 2026
- Annex A
Methodology
How the edition was made: methods, the model card, the evidence cut and its age, the acceptance record and the glossary.
Contents
- ·Edition home
- ·Executive summary
- 1South Asia’s risk travels through rivers, monsoons and shared supply
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Second deficient monsoon with unsettled river treaties
- 6Readings from the other desks
- 7The 2027 agenda
- 8Systems in depth
- AMethodology
- BData appendix
- CReferences and record
- ·Complete edition, for print
A.1Methods
The regional baseline uses published values and four simple derivations. Each is shown in full so that any reader can reproduce it.
| No. | Derivation | Calculation | Result |
|---|---|---|---|
| (1) | India’s share of the eight-state population, 2025 | 1,463.87 ÷ 1,991.32 | 73.5% |
| (2) | India’s share of the eight-state emissions excluding land use, 2024 | 4,371.17 ÷ 5,234.45 | 83.5% |
| (3) | India’s share of the eight-state cereal production, 2024 | 391.12 ÷ 536.15 | 73.0% |
| (4) | India’s share of the seven-state output, 2025, excluding Afghanistan | 3,956.07 ÷ 4,985.33 | 79.4% |
| Strength | Definition |
|---|---|
| STRONG | a disruption in the source system has historically changed the target system’s service or output within one season, in more than one region |
| MODERATE | an effect is documented but buffered or slower |
| WEAK | an effect is plausible but not documented at regional scale |
| Label | Rule |
|---|---|
| Reported | value as issued by its source, with year |
| Inferred | reasoned from cited evidence; never a measurement |
| Estimated | Nexus analytical value with stated method |
| Scenario | conditional on stated assumptions |
| Expert input | structured editorial judgement awaiting evidence |
A.2Model card: Regional System Model v0
- Model ID
- MDL-SAS-REGIONAL · v0.1
- Purpose
- represent South Asia as coupled water, energy, food, health and biodiversity systems across member countries, with forcing and transmission layers
- Family
- graph-based system of systems
- Inputs
- the cited sources of this edition; no proprietary data
- Method
- expert-specified coupling strengths (STRONG · MODERATE · WEAK) from assessments and analogue events
- Validation
- none yet, first validation against federation evidence in 2027
- Uncertainty
- qualitative; strengths are hypotheses, not measurements
- Domain of validity
- regional scale; not for national, basin or asset-level use
- Reproducibility
- strength table and sources published in this edition
typed in v0
documented within one season
documented, buffered
plausible, undocumented
A.3The baseline evidence cut
Every Nexus edition is published from a frozen evidence cut. The regional baseline cut is documentary: it pins the exact edition of every source cited. Federation cuts begin with the first national Foundry cuts in 2027.
- Cut ID
- NQ-REG-SAS-2026-Q0-1
- Type
- baseline documentary cut
- Resolution policy
- pinned · as of 30 September 2026
- Sources pinned
- 52 cited sources, each at the edition and access date in the references
- Model runs
- none at baseline, analytical values are stated with their method
- Digest
- computed at freeze and recorded in the publication record
- Supersedes
- nothing, first cut of the series
- Superseded by
- NQ-REG-SAS-2027-Q1-1 at the Q1 2027 close
Lineage
- 01
source edition
- 02
pinned citation
- 03
finding
- 04
page
- 05
publication record
| Element | Baseline 2026 | 2027 regional annual |
|---|---|---|
| Sources | cited publications, pinned by edition | national, regional and sector cuts through one graph |
| Analysis | stated methods and editorial estimates | typed analysis specifications |
| Models | Regional System Model v0 specification | model runs with receipts |
| Findings | twelve baseline findings | findings re-bound to federation evidence |
| Review | five passes scheduled | five passes on the exact digest |
A.4Evidence age and coverage
A 2026 edition rests on evidence observed in many different years. This page shows each time base, so that no single year label hides older evidence.
| Indicator | Observed | Released | Cadence | Next release |
|---|---|---|---|---|
| Population | 2025 | not recorded | annual | annual |
| Output and growth | 2025 | not recorded | annual | annual |
| Greenhouse gases | 2024 | not recorded | annual | annual |
| Electricity by fuel | 2021 to 2024 | not recorded | annual | annual |
| Freshwater series | 2022 | not recorded | annual | annual |
| PM2.5 exposure | 2023 | not recorded | annual | annual |
| Air pollution mortality | 2019 | not recorded | occasional | not recorded |
| FAO country briefs | 2025 to 2026 | Feb to Sep 2026 | several a year | next brief |
| WMO Asia report | 2025 | Jun 2026 | annual | annual |
| System | Coverage | Thinnest dimension |
|---|---|---|
| Climate and hazards | PARTIAL | final flood tolls; heat deaths |
| Energy | PARTIAL | cross-border power flows |
| Water | PARTIAL | Indus flows and storage |
| Food | PARTIAL | Bhutan and Maldives undernourishment |
| Health | PARTIAL | heat deaths; recent air mortality |
| Biodiversity | THIN | condition outside protected areas |
| Finance | THIN | insured and uninsured losses |
| Digital | THIN | dependency mapping |
| Field | Source that would fill it | Blocker |
|---|---|---|
| Cross-border electricity flows and capacity between India, Nepal, Bhutan and Bangladesh | national transmission utilities and the Indian Central Electricity Authority | not retrieved; no operator series was read |
| Final death toll, displacement and losses of the 2025 monsoon floods in Pakistan, by province | Pakistan National Disaster Management Authority season reports43 | not opened; the figures seen in search results conflicted |
| Casualty count and cause of the 26 August 2026 flash flood on the Nepal and China border | Nepal government records and the ICIMOD report listed on 13 October 202652 | not opened; the one account read gives no precise count and the cause is unresolved25 |
| Deaths and injuries of the 31 August 2025 earthquake in eastern Afghanistan | USGS event record44 and WHO situation reports | the event page returned no content and the WHO page states no figure26; reports differ |
| Official toll of Cyclone Ditwah in Sri Lanka, November 2025 | Sri Lanka Disaster Management Centre situation reports42 | not opened; figures seen in news results rose over time |
| Status of the renewal of the Ganges Water Treaty, which expires in December 2026 | India and Bangladesh Joint Rivers Commission and the treaty text40 | the analytic brief fetched is an image-only file and could not be read41; no signed text found |
| Indus basin reservoir storage and river flows in Pakistan and India | Pakistan water authority and Indian Central Water Commission bulletins | not retrieved |
| Heat-related deaths in 2025 and 2026, by state | national health ministries and WHO | no consistent series found; the India edition notes the same gap27 |
| Prevalence of undernourishment for Bhutan and the Maldives | FAO and the World Bank undernourishment series11 | the series returned no value for these two states |
| Growth and inflation for Afghanistan for 2026 | IMF projections15 | the series returned a value for 2025 only |
| Emissions on each state’s own inventory basis, including land use | national communications and reports to the UNFCCC | not opened; the series in3 uses one common basis and may differ from national inventories |
| Glacier mass change by basin in the Hindu Kush Himalaya | ICIMOD and the World Glacier Monitoring Service37 | the WMO page states glacier retreat without figures21 |
| Insured and uninsured disaster losses by state | insurers, reinsurers and national finance ministries | not retrieved |
| Capability rungs: early warning, reserves, response, recovery, social protection, infrastructure, workforce | disaster authorities, weather services, utilities and ministries | not reviewed by evidence close |
A.5Evidence cards: two anchor sources
Issued by the World Bank. Annual series. Role: binds population, output and emissions in the profile and regional reading. Latest values differ by state and are stated beside each figure; the source updated on 8 October 2026.
EVD-SAS-001
Issued by the Food and Agriculture Organization. Reference dates from February to September 2026. Role: binds food supply and food insecurity findings. Coverage is one brief per state.
EVD-SAS-002
| Dimension | EVD-SAS-001 | EVD-SAS-002 |
|---|---|---|
| Completeness | eight states; some series lack Afghanistan, Bhutan or the Maldives | one brief per state; Bhutan and the Maldives not read |
| Timeliness | latest values from 2021 to 2025 | reference dates in 2026 |
| Revision | revised by the issuer; not tracked here | revised with each brief |
| Method transparency | published methodology | published methodology |
| External validation | not assessed in this edition | not assessed in this edition |
Evidence cards to follow in Q1 2027
A.6Publication acceptance record
Editorial self-check at evidence close. Every applicable item carries a disposition; the remaining items are review, approval and deposit.
| Group | Area | Items | Pass | N/A | Pending |
|---|---|---|---|---|---|
| D1 | Identity and scope | 8 | 8 | 0 | 0 |
| D2 | Source and data | 12 | 9 | 1 | 2 |
| D3 | Analysis and models | 12 | 3 | 8 | 1 |
| D4 | Findings and claims | 9 | 8 | 0 | 1 |
| D5 | Figures, tables, maps | 10 | 6 | 2 | 2 |
| D6 | Editorial and citations | 10 | 8 | 0 | 2 |
| D7 | Review and approval | 13 | 0 | 0 | 13 |
| D8 | Artefact and design | 12 | 7 | 0 | 5 |
| D9 | Registry and release | 9 | 0 | 0 | 9 |
Publication gate
- Conditions met
- 14 of 23 at evidence close
- Blocking problems
- none recorded
- Open conditions
- reviews, approval of the exact digest, deposit, registry pointer
Not applicable at baseline
- Model runs
- first runs in Q1 2027
- Maps
- plates in Q2 2027
- Waivers
- none
A.7Status words
| Status | What it means |
|---|---|
| Observed | Measured directly and published by the source. |
| Reported | Published statistics of an official or institutional source. |
| Declared | Stated by the body concerned; not independently measured. |
| Estimated | A Nexus estimate from cited evidence, with its method in Annex A. |
| Modelled | Produced by a stated model from cited inputs. |
| Inferred | Reasoned from cited evidence; not measured. |
| Forecast | A projection by the cited source. |
| Simulated | A simulation result under stated assumptions. |
| Scenario | A conditional statement under stated assumptions; never a prediction. |
| Expert input | Expert judgement, recorded with its basis. |
| Candidate | Proposed for a later edition; not yet evidence. |
| Evidence-quality levels (EQL 1 to 5) grade the source behind a value; they are not a score of the subject. | |
A.8How the edition is made, released and corrected
Every edition is built from a sealed evidence cut, reviewed under three keys, signed and deposited before any site shows it as published; corrections go to Nexus Standards as change proposals and feed the next cut.
| Step | What happens | Source |
|---|---|---|
| 01 Evidence arrives from the pillars | Foundry seals observations and indicator series, Universe hands over after-action and scenario findings, and contributions are screened at every gateway, including this site’s. | |
| 02 The cut is sealed | On the cut date the evidence is pinned under one identifier, so anyone can rebuild the edition from exactly what it was built on. | |
| 03 The edition is assembled | The edition is drafted from its template and content pack. Agents may draft; they never publish and never decide. | |
| 04 The keys turn | At the publisher of record the truth key comes first: every value is checked against its source or stated method before the meaning and capital keys turn. No edition moves on until every key has been turned by a named steward. | |
| 05 The gate opens | A named approver releases one exact digest of the edition; any change after this point is a new version, never a silent edit. | |
| 06 Signed and deposited | The PDF, the web edition and the data bundle are signed together with a manifest and an RO-Crate description, and deposited on Zenodo with a concept and a version DOI. | |
| 07 Published on its desk’s site | Only then does the edition show as published on its desk’s Reports site, and the Collection lists it as a part. | |
| 08 Corrections go to Standards | Method and correction findings go to Nexus Standards as change proposals; citations, corrections and new contributions feed the next evidence cut. |
A teaching model of the process, not a forecast and not a record of any run; dates and counts on this page come from the programme record. Sources: Reports governance at GCRI Canada (2026); Zenodo, repository of record for Reports deposits (2026).
Lifecycle, one state at a time: Draft, Computed, Evidence bound, Reviewed, Approved for release, Published, Corrected, Superseded. This edition is a draft.
A.9Glossary and abbreviations
| Term | Meaning |
|---|---|
| Baseline Edition | the inaugural annual edition that fixes the reference state for the series |
| WEFH+B | water, energy, food, health and biodiversity, the national nexus core |
| Coupling | a typed dependency through which one system transmits to another |
| Protection gap | the share of losses not covered by insurance |
| Capability ladder | LISTED → EXISTS → ADEQUATE → TESTED → DEMONSTRATED |
| EQL | evidence-quality level, 1–5 |
| Evidence cut | a frozen resolution of exact sources and versions |
| NNC · NLC · NWG | National Nexus Consortium · National Leadership Council · National Working Groups |
| Abbreviation | Expansion |
|---|---|
| AFG | Afghanistan |
| BGD | Bangladesh |
| FAO | Food and Agriculture Organization of the United Nations |
| GIEWS | Global Information and Early Warning System |
| ICIMOD | International Centre for Integrated Mountain Development |
| IMF | International Monetary Fund |
| IPC | Integrated Food Security Phase Classification |
| LPA | long period average |
| LULUCF | land use, land-use change and forestry |
| NPL | Nepal |
| PM2.5 | fine particulate matter up to 2.5 micrometres |
| UNDRR | United Nations Office for Disaster Risk Reduction |
| WDI | World Development Indicators |
| WMO | World Meteorological Organization |
| IWT | Indus Waters Treaty |
A.10Technical annex
| Item | Annex | Contents | Status |
|---|---|---|---|
| A.1 | Indicator definitions | the regional indicator set, with units and sources | IN THIS EDITION |
| A.2 | Coupling strengths | the twenty-cell matrix and its rationale | IN THIS EDITION |
| A.3 | Scenario specification | SCN-SAS-DRY-01 assumptions and signposts | IN THIS EDITION |
| A.4 | Capability placements | rung evidence for fifteen functions | IN THIS EDITION |
| A.5 | Model diagnostics | first runs and validation | 2027 |
| A.6 | Sensitivity analyses | influence of coupling strengths | 2027 |
| A.7 | Member-country notes | atlas cards for every member country | Q2 2027 |
| A.8 | Review statements | pass-by-pass review record | AT RELEASE |
A.1 · indicator definition: emissions excluding land use
- Construct
- annual greenhouse gas emissions without land use, land-use change and forestry
- Unit
- Mt CO₂e, using AR5 global warming potentials
- Scope
- calendar year
- Source
- World Bank World Development Indicators total greenhouse gas series3
- Revision
- revised by the issuer; not tracked here
- Known limits
- the upstream compiler is not stated on the response read; national inventories may differ in basis
Notes
Numbers are the edition’s reference numbers, so a note reads the same in every chapter. The full list, with every source and its licence, is in Annex C. Annex C, references
- 43UNVERIFIED, not opened: National Disaster Management Authority, Pakistan (ed.), 2025 monsoon season reports (death tolls from about 280 in July to about 1,000 at season end seen in news results; the figures conflicted and are not used). NDMA, Islamabad. Observation year 2025. Accessed 2026-11-03.back
- 52POST-CLOSE, context only: International Centre for Integrated Mountain Development (ed.), publications listing (page opened; one report dated 13 October 2026 on the Gyirong and Rasuwa disaster of 26 August 2026 is listed by title only; its content was not read). ICIMOD, Kathmandu. Observation year 2026. Accessed 2026-11-03.back
- 25S. J. Cook, The August 2026 Rasuwa disaster (blog post, 10 September 2026; ice-rock avalanche, initial volume about 100 million cubic metres; no precise casualty figure). Royal Scottish Geographical Society, Perth. Observation year 2026. Accessed 2026-11-03.back
- 44UNVERIFIED, not opened: United States Geological Survey (ed.), M 6.0 earthquake, eastern Afghanistan, 31 August 2025, event page (the page returned no content; reported tolls of 2,217 from officials and higher from WHO seen in search results and not used). USGS, Reston. Observation year 2025. Accessed 2026-11-03.back
- 26WHO Health Cluster (ed.), Afghanistan earthquake (page dated 2 September 2025; magnitude 6.0 on 31 August 2025; Kunar, Laghman, Nangarhar and Nuristan; no casualty figures stated). World Health Organization, Geneva. Observation year 2025. Accessed 2026-11-03.back
- 42UNVERIFIED, not opened: Disaster Management Centre, Sri Lanka (ed.), Situation reports on Cyclone Ditwah (a toll of 649 deaths by 25 January 2026 and about 2.08 million people affected taken from search summaries of news and ReliefWeb; not used for any figure in the findings). DMC, Colombo. Observation year 2025. Accessed 2026-11-03.back
- 40UNVERIFIED, not opened: India and Bangladesh (parties), Treaty between the Government of the Republic of India and the Government of the People’s Republic of Bangladesh on sharing of the Ganga/Ganges waters at Farakka, signed 12 December 1996 (expiry in December 2026 and the absence of a signed renewal taken from search summaries of news reports and an analytic brief). Joint Rivers Commission, Dhaka and New Delhi. Observation year 2026. Accessed 2026-11-03.back
- 41UNVERIFIED, not opened: POST-CLOSE, context only: Institute of South Asian Studies (ed.), ISAS Brief 1428 on the Ganges treaty (12 October 2026; the file fetched was an image-only PDF and no text could be read). ISAS, National University of Singapore. Observation year 2026. Accessed 2026-11-03.back
- 27S. Valadbaygi (ed.), India Baseline Edition 2026 (draft pack read for findings CLI-002 and CLI-003: 2026 monsoon at 87% of the long period average; the weather-service statements it cites were read by that edition, not by this one). The Global Centre for Risk and Innovation (GCRI) for the Nexus Consortium, Toronto, 2026. Observation year 2026. Accessed 2026-11-03.back
- 11World Bank (ed.), World Development Indicators, SN.ITK.DEFC.ZS prevalence of undernourishment and SI.POV.DDAY poverty headcount at $3.00 a day (2021 PPP), eight states (no value for Bhutan and Maldives undernourishment; poverty years 2019 to 2024). World Bank, Washington. Observation year 2024. Accessed 2026-11-03.back
- 15International Monetary Fund (ed.), DataMapper, World Economic Outlook series NGDP_RPCH real GDP growth and PCPIPCH inflation, projections for 2025 and 2026 (database vintage as served on the access date; the country filter was ignored and the full table was read). IMF, Washington. Observation year 2026. Accessed 2026-11-03.back
- 3World Bank (ed.), World Development Indicators, EN.GHG.ALL.MT.CE.AR5 total greenhouse gas emissions excluding LULUCF and EN.GHG.CO2.MT.CE.AR5, eight states. World Bank, Washington. Observation year 2024. Accessed 2026-11-03.back
- 37P. Wester, A. Mishra, A. Mukherji and A. B. Shrestha (eds.), The Hindu Kush Himalaya Assessment: Mountains, Climate Change, Sustainability and People. Springer, Cham, 2019 (bibliographic record opened in Crossref; volume not read; no figure drawn from it). Observation year 2019. Accessed 2026-11-03.back
- 21World Meteorological Organization (ed.), State of the Climate in Asia 2025 (series page opened, published 17 June 2026; the page states no South Asia figures). WMO, Geneva. Observation year 2025. Accessed 2026-11-03.back
- 1DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, SP.POP.TOTL population total, Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka (data service, source updated 8 October 2026). World Bank, Washington. Observation year 2025. Accessed 2026-11-03.back
- 16Food and Agriculture Organization (ed.), GIEWS Country Brief: Pakistan (reference date 6 February 2026; cereal output about 53 Mt in 2025; floods affected at least 5.8 million people; about 10 million at IPC Phase 3 or worse April to July 2025). FAO, Rome. Observation year 2025. Accessed 2026-11-03.back
- 17Food and Agriculture Organization (ed.), GIEWS Country Brief: Bangladesh (reference date 4 September 2026; 2026 paddy forecast 61.9 Mt; 18.1 million projected at IPC Phase 3 or worse September to December 2026). FAO, Rome. Observation year 2026. Accessed 2026-11-03.back
- 18Food and Agriculture Organization (ed.), GIEWS Country Brief: Afghanistan (reference date 15 September 2026; 13.8 million projected at IPC Phase 3 or worse; about 2.65 million returns by late July 2026). FAO, Rome. Observation year 2026. Accessed 2026-11-03.back
- 51UNVERIFIED, not opened: S. Valadbaygi (ed.), Reports: The Foundational Edition, Volumes I and II. Reports series, Edition 2026–2030, V1.0. GCRI for the Nexus Consortium, Toronto, 2026. Observation year 2026. Accessed 2026-11-03.back
- 50UNVERIFIED, not opened: S. Valadbaygi (ed.), Global Systems Risk & Resilience Report 2026: Baseline Edition (draft pack used as the structural base of this edition; its text was not read for this edition). GCRI for the Nexus Consortium, Toronto, 2026. Observation year 2026. Accessed 2026-11-03.back
