Stödzoner

Stödzoner is a Swedish term used within safety science and engineering to describe zones around a source of a sudden disturbance, such as an explosion, impact, or shock wave, where the effects are strong enough to pose risk to people, structures, or equipment. The concept is applied across fields such as military planning, civil defense, industrial safety, and urban risk assessment.

Definition and delineation of stödzoner is typically based on measurable effects rather than a single distance. Common criteria include overpressure, impulse, thermal radiation, and the likelihood of debris projection. The exact thresholds depend on the regulation, the activity, and the level of acceptable risk. In practice, engineers often relate the source strength to distance using TNT-equivalent energy and employ the idea of scaled distance, Z = R / W^(1/3), to compare different scenarios and to estimate zone radii.

Applications of stödzoner include designing blast-resistant structures, planning safe setback distances for facilities, conducting hazard analyses, and supporting emergency response planning. In these contexts, stödzoner help identify areas that require protective measures, access controls, or evacuation planning.

Limitations exist because real-world boundaries are influenced by terrain, building shielding, weather, and obstructions. Consequently, stödzoner are approximations that inform safety decisions rather than precise boundaries; probabilistic considerations and site-specific analyses are often necessary.

See also: blast zone, overpressure, hazard analysis, emergency planning, TNT-equivalent.