What this data measures
Debris-flow hazard layers define areas historically affected by or predicted to experience debris flows.
The data typically distinguishes source areas, transit corridors, and deposition zones.
How to interpret it
Debris-flow hazard is most relevant for properties in valley floors along steep alpine or pre-alpine streams.
A property in a deposition zone can be exposed to a flow triggered upstream, so upstream weather and geology matter as much as immediate surroundings.
Cantonal hazard maps are the authoritative reference for zoning and planning decisions.