risikosonen

Risikosonen is a concept used in risk assessment and spatial planning to designate geographic areas with elevated risk for a specified hazard. The term combines risk with zone and is often used in Finnish planning and safety contexts; in English it is commonly translated as "risk zone" or "risk-prone area." A risikosonen is defined by a risk level, which can be expressed as the expected annual damage or probability of harmful impact, and is mapped for decision making.

Determination: The delineation relies on hazard data (such as flood, landslide, wildfire, seismic activity, industrial accidents), exposure (where people and assets are located), and vulnerability (how severe the impact would be). These inputs are integrated in a risk model to produce categories (for example low, medium, high) or continuous risk values, typically visualized with GIS maps.

Applications: Risikosonen guide planning and regulation. They inform land use restrictions, building codes, mitigation requirements (e.g., elevation, flood defenses, seismic reinforcement), and emergency planning. They also influence insurance pricing and evacuation planning.

Examples: Flood-prone river valleys; coastal flood and storm surge zones; wildfire-prone forest margins; industrial hazard zones around chemical plants; seismic risk areas in earthquake-prone regions.

Limitations: The accuracy of risikosonen depends on data quality and model assumptions. Risk is dynamic, affected by climate change, land use, and population changes, so zones require regular updates and, ideally, multi-hazard considerations.