Madagascar sits in one of the world’s busiest cyclone corridors. Every year, between November and April, warm Indian Ocean water east of the island fuels tropical cyclones that strike a coast where the population is growing quickly and the infrastructure is not.
This report combines the observed cyclone record (1975–present), the science on how tropical cyclones respond to a warming ocean, and a decadal impact model that projects cyclone consequences on the ground through 2100. It is designed for anyone thinking about adaptation finance, cyclone-resilient infrastructure, or loss-and-damage response in Madagascar.
The headline numbers
- ~4.6× rise since the 1980s in the destructive capability bearing on Madagascar’s people — storm intensity multiplied by the population in the storm’s path.
- On course for ~8× by the 2050s under central climate projections.
- The count of storms is flat. It is the intensity of those that make landfall, and the exposure of the coastlines they cross, that drive the trend.
- Adaptation strategy follows from the intersection of stable geographic exposure with rising storm intensity. For SaniTap, that means water infrastructure engineered to survive the storm the coast will face in the 2050s, not the storm that hit it in 1985.
Read the full interactive report
The interactive report includes:
- Total destructive capability on the population — the composite metric that captures both storm strength and human exposure, plotted from 1975 to today.
- Cyclone count — why the number of storms per year is essentially flat.
- Cyclone intensity — why the storms that do form are stronger, with observational and modelled evidence.
- Combined view — intensity up, moderated only slightly by fewer storms.
- Projected PDI reaching Madagascar to 2100 — power-dissipation index projections under central climate scenarios.
- Decade-by-decade modelled impact — the tabulated outputs of the decadal impact model, showing projected consequences on populations and infrastructure through 2100.
- What stronger storms mean on the ground — the translation of the scientific numbers into implications for the built environment and community water access.
- What the science projects — the caveats, confidence levels, and open questions.
Why this matters for SaniTap
The scientific case for cyclone-resilient infrastructure does not rely on predicting the track of any single storm. It rests on two well-established points:
- The exposed coast is stable. The same Malagasy communities that were hit in the 1980s will be hit in the 2050s and beyond. This is a geographic fact.
- The storms crossing that coast are stronger. The trend in tropical-cyclone intensity in the South-West Indian Ocean, and specifically in the fraction of storms reaching Category 3 or higher, is measurable and projected to continue.
Together these two facts point to a single conclusion: any piece of community water infrastructure built today should be engineered to survive the design storm expected in the middle of its operating life, not the storm that hit the site when the previous infrastructure was designed.
This is the logic behind SaniTap’s cyclone-resistant safe drinking water methodology, developed under the Adaptation Benefits Mechanism.
Related work
- When lightning strikes twice — predicting cyclones in Madagascar — the science of cyclone prediction, three prediction horizons, and the adaptation strategy that follows.
- SaniTap’s Adaptation Benefits Mechanism programme — how the cyclone-resistant SDW methodology channels adaptation finance into rebuilding and hardening community water access.