Same rain. Less water.

Two catchments receive the same rain. One floods. Which did your trigger price?

A hundred millimetres of rain on intact forested ground does no damage. The same hundred millimetres on a stripped catchment next door floods it. The index reads the air, while the loss depends on what the ground does with the water, and between those two sits a term the pricing does not carry.

The trigger fires on both or neither. The loss lands on one. Every payout that fails to match a loss traces back to this gap.

What is the 92% made of?

Swiss Re Institute, sigma 01/2026 and its Asia analysis, March 2026.

An underwriter prices land before covering it, and pricing needs a read on what the land is. Across most of that ground nobody has done one, because no premium was ever large enough to justify the survey.

So the whole area is declined. Not the damaged parts, but every hectare, because nothing separates them. In most abandoned zones the sound land is the majority, and it is refused alongside the ruined land. That refusal enters the statistics as low penetration. It is also the largest body of unwritten sound risk in the market, and the first carrier able to separate it from the ruined ground writes it alone.

Is your backtest fitted on the ground under the policy today?

A record describes the catchment as it was when the record was made. If upstream cover has since been cleared, rain that once soaked in now runs off, and the record describes a landscape that no longer exists. A longer record only makes the old landscape more convincing.

Vegetation indices and soil moisture readings already sit in index design. Each reads condition on a date. None answers whether the ground has passed the point beyond which it no longer recovers.

What would you need to know before setting the trigger?

Hazard, exposure and loss history each describe what happens to the ground. None of them describes the ground itself. A classification of the catchment does, in three statements and nothing else.

• Condition. Where the ground sits on a five-class scale, from fully productive to exhausted.
• Threshold. Whether it has crossed the line past which inputs no longer restore it. That crossing has a name, biosenescence, and it does not reverse.
• Irreversibility marker. The specific physical change that cannot be undone, named, so the finding can be argued with.

It does not forecast an event, a date or a probability. It gives no view on whether to write, decline or reprice. Every file states the conditions under which it is wrong, and any one of them, evidenced, gets the finding restated.