- Global Water 2026
- Chapter 5
Multi-basin drought under heat
A conditional statement under stated assumptions, never a prediction.
5.1Assumptions
Scenario SCN-GS01-MBD-01: what is assumed, and what is held constant.
- Baseline
- the 2026 reference state in this edition
- Drivers
- a strong warm season with below-normal precipitation across several major basins in the same year
- Analogues
- 2022 drought in Europe and China; 2010–2012 droughts
- Interventions
- none modelled, the specification describes the unmitigated case
- Run state
- narrative specification; quantified run scheduled for 2027
5.2The cascade, step by step
- 1
CLI → WAT
low precipitation and heat cut river flows and reservoir inflow
2022
- 2
WAT → ENE
hydro output falls; thermal plants curtail for hot cooling water
2022
- 3
WAT → FOO
irrigation restrictions and heat cut yields
2022 · 2012
- 4
WAT → INF
low river levels restrict inland shipping
2022
- 5
WAT → HLT
urban rationing; water-quality problems
2018 Cape Town
- 6
FOO → TRD
export restrictions transmit the shock
2010
5.3The scenario as a table of steps
How the shock in scenario SCN-GS01-MBD-01 would travel through Global Water’s coupled systems, step by step, under the assumptions the edition states.
| Step | What happens | Source |
|---|---|---|
| 01 Climate to water | Low precipitation and heat cut river flows and reservoir inflow. Analogue or source: 2022. | Edition GS-01, scenario SCN-GS01-MBD-01, step 1 |
| 02 Water to energy | Hydro output falls; thermal plants curtail for hot cooling water. Analogue or source: 2022. | Edition GS-01, scenario SCN-GS01-MBD-01, step 2 |
| 03 Water to food | Irrigation restrictions and heat cut yields. Analogue or source: 2022 · 2012. | Edition GS-01, scenario SCN-GS01-MBD-01, step 3 |
| 04 Water to infrastructure | Low river levels restrict inland shipping. Analogue or source: 2022. | Edition GS-01, scenario SCN-GS01-MBD-01, step 4 |
| 05 Water to health | Urban rationing; water-quality problems. Analogue or source: 2018 Cape Town. | Edition GS-01, scenario SCN-GS01-MBD-01, step 5 |
| 06 Food to trade | Export restrictions transmit the shock. Analogue or source: 2010. | Edition GS-01, scenario SCN-GS01-MBD-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: Global Water 2026, scenario SCN-GS01-MBD-01 (2026); Global Water 2026, references (NR-CIT-1) (2026).