2. Torrential phenomena

Torrential phenomena are manifestations of the appearance or increase in the flow of steeply sloping rivers. They are characterized by the importance of solid material transport relative to liquid flow.

Torrential phenomena develop in small watersheds with specific characteristics. These basins constitute torrential apparatuses.

Torrents are located in the upstream parts of large watersheds and contribute significantly to their sediment balance.

Solid transport is associated with most river floods, but outside the torrential domain, the influence of solid transport on flow height is negligible. The study of these lightly laden floods falls within the scope of hydraulics and not of the phenomena dealt with here.