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Second deficient monsoon with unsettled river treaties

A conditional statement under stated assumptions, never a prediction.

3 min read0 figures0 tables7 notesNR-REGIONAL-SAS-2026-BASELINE

Contents
  1. ·Edition home
  2. ·Executive summary
  3. 1South Asia’s risk travels through rivers, monsoons and shared supply
  4. 2Key findings
  5. 3Systems and sectors at baseline
  6. 4Risks and capability
  7. 5Second deficient monsoon with unsettled river treaties
    1. 5.1 Assumptions
    2. 5.2 The cascade, step by step
    3. 5.3 The scenario as a table of steps
  8. 6Readings from the other desks
  9. 7The 2027 agenda
  10. 8Systems in depth
  11. AMethodology
  12. BData appendix
  13. CReferences and record
  14. ·Complete edition, for print

5.1Assumptions

Scenario SCN-SAS-DRY-01: what is assumed, and what is held constant.

Baseline
the 2026 reference state in this edition
Drivers
a monsoon below the long period average for a second year, with high dry-season demand
Analogues
India monsoon 2026 at 87% of average27; Nepal paddy loss in 202520; Indus and Ganges treaty positions2240
Interventions
none modelled, the specification describes the unmitigated case
Run state
narrative specification; quantified Foundry run scheduled for Q1 2027

5.2The cascade, step by step

  1. 1

    CLI → WAT

    low rainfall cuts river flow and recharge on the plains

    monsoon 202627

  2. 2

    WAT → FOO

    irrigation shortfall lowers paddy and wheat output

    Nepal paddy 202520

  3. 3

    WAT → ENE

    hydropower falls where hydro dominates, and cooling water tightens elsewhere

    no analogue bound

  4. 4

    CLI → HLT

    heat and smoke raise health load

    air pollution mortality 20198

  5. 5

    FOO → FIN

    prices and household budgets tighten where food insecurity is already high

    IPC projections 20261718

  6. 6

    WAT → governance

    treaty positions shape the room for joint flow management

    award and expiry2240

5.3The scenario as a table of steps

How the shock in scenario SCN-SAS-DRY-01 would travel through South Asia’s coupled systems, step by step, under the assumptions the edition states.

StepWhat happensSource
01 Climate to waterLow rainfall cuts river flow and recharge on the plains. Analogue or source: monsoon 2026 [27].Edition REG-SAS, scenario SCN-SAS-DRY-01, step 1
02 Water to foodIrrigation shortfall lowers paddy and wheat output. Analogue or source: Nepal paddy 2025 [20].Edition REG-SAS, scenario SCN-SAS-DRY-01, step 2
03 Water to energyHydropower falls where hydro dominates, and cooling water tightens elsewhere. Analogue or source: no analogue bound.Edition REG-SAS, scenario SCN-SAS-DRY-01, step 3
04 Climate to healthHeat and smoke raise health load. Analogue or source: air pollution mortality 2019 [8].Edition REG-SAS, scenario SCN-SAS-DRY-01, step 4
05 Food to financePrices and household budgets tighten where food insecurity is already high. Analogue or source: IPC projections 2026 [17] [18].Edition REG-SAS, scenario SCN-SAS-DRY-01, step 5
06 Water to governanceTreaty positions shape the room for joint flow management. Analogue or source: award and expiry [22] [40].Edition REG-SAS, scenario SCN-SAS-DRY-01, step 6

A teaching model of a conditional scenario under the edition’s stated assumptions: not a forecast, not a prediction and not a warning. Sources: South Asia 2026, scenario SCN-SAS-DRY-01 (2026); South Asia 2026, references (NR-CIT-1) (2026).

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

  1. 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
  2. 20Food and Agriculture Organization (ed.), GIEWS Country Brief: Nepal (reference date 18 August 2026; cereals 11.1 Mt and paddy 5.7 Mt in 2025, paddy down 4.2%). FAO, Rome. Observation year 2025. Accessed 2026-11-03.back
  3. 22T. Gamble-Eddington, Court of Arbitration Finds that the Indus Water Treaty Remains in Force (International Law in Brief, 21 September 2026; award and order of 31 August 2026, PCA Case No. 2023-01). American Society of International Law, Washington. Observation year 2026. Accessed 2026-11-03.back
  4. 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
  5. 8World Bank (ed.), World Development Indicators, EN.ATM.PM25.MC.M3 mean annual PM2.5 exposure (2023) and SH.STA.AIRP.P5 mortality rate attributed to household and ambient air pollution (2019), eight states. World Bank, Washington. Observation year 2023. Accessed 2026-11-03.back
  6. 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
  7. 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

Cite this chapter

Valadbaygi, S. (Ed.). (2026). Chapter 5: Second deficient monsoon with unsettled river treaties. In South Asia Regional Systems Risk and Resilience Report 2026: Baseline Edition, The State of South Asia’s Interdependent Systems. (Baseline Edition 2026, Report No. NR-REGIONAL-SAS-2026-BASELINE) [Draft under review]. The Global Centre for Risk and Innovation (GCRI).

Every citation form of the whole report, BibTeX and RIS included, is on the edition home. Cite this report

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