ränning

Ränning is a Swedish noun used in geomorphology, hydrology, agriculture, and civil engineering to describe the formation and presence of channels created by running water. The core sense is the development of narrow, elongated depressions or trenches in soil, sediment, or bedrock where surface water concentrates into a flow. In geomorphology and soil science, ränning is closely related to rill erosion. Repeated runoff can deepen and widen these channels, altering drainage patterns and increasing sediment transport.

In agricultural contexts, ränning may refer to furrows or grooves that form in fields either naturally through rainfall impact and runoff or are created deliberately to improve drainage and seedbed preparation. In some uses, the term also covers small drainage channels that collect runoff in fields and pastures.

In urban or civil engineering, ränning can denote drainage channels or gutters designed to collect and direct stormwater toward a sewer or watercourse, helping to prevent surface flooding. The term thus spans natural erosion processes and human-made drainage systems, reflecting how water flow shapes landscapes and built environments.

Etymology: the noun derives from the verb ränna (“to run in a channel”) and is related to the plural rännor (“channels,” gutters). The word is common in Swedish-language discussions of erosion, soil conservation, drainage, and land management.

See also: ränna, rännor, rill erosion, gully, erosion.