Torrent
A torrent is a steep mountain stream that sometimes swells a lot and carries with it large amounts of rock rubble , debris , soil, wood or entire tree trunks . The main characteristics of torrents in the Alpine region are the steep gradient and, due to the snowmelt and violent thunderstorms , the discharge values vary greatly within a short period of time . Torrents are also less common in the hilly plains. There they appear on steep hill slopes. They typically do not overcome a large difference in altitude, but often have a larger catchment area than mountain streams.
Torrents can be roughly divided into three sections. In the collecting funnel on the mountain slopes, the water and eroded soil and stone rubble collects . It then flows through a drainage channel at high speed into the alluvial fan , where the debris is deposited .
In Austria, a torrent is defined as follows in Section 99 of the Forest Act :
“A torrent within the meaning of this federal law is a continuously or temporarily flowing body of water which, through swelling that occurs rapidly and lasts only for a short time, removes solids from its catchment area or from its creek bed in dangerous proportions, carries them with it and deposits them inside or outside its bed or to another body of water. "
hazards
The material transported by the torrent can pose great dangers for people , animals and cultivated land:
- Heavy erosion - deepening of the stream bed
- Following possible landslides
- Endangerment of the mountain and protective forest
- Formation of a ravine
- Triggering a mudslide
- Relocation of a narrow area and impoundment - endangering settlements when emptying
- Excessive deposits of rubble, debris and coarse gravel - sometimes further down the valley on the rubble - or alluvial cone
- This makes it possible to relocate the creek bed
A torrent control as technical flood protection helps against some of these dangers .
Is responsible usually a specialist or forestry department of the region, in Austria the torrent and avalanche control . In Switzerland torrent corrections and -verbauungen be through the Federal Law on Hydraulic determined and the Federal Office for Water and Geology coordinated.
Web links
- Torrents. Website of the Austrian Ministry of Life