Big river of the low mountain range
Type 9.2 large rivers of the low mountain range is one of the river types specified by LAWA .
structure
The major rivers of the low mountain range show relatively different forms, as the gradient and the bed substrate vary greatly. There are mainly crushed stone and gravel as bed substrates, but there are also larger sandy or loamy sections. In the relatively flat course of the river, which alternates between areas with fast and slow-flowing water, there are large, mostly vegetation-free gravel banks in near-natural rivers . In the case of unspoilt rivers of this type that hardly exist in Germany today, large-scale course shifts occur again and again.
The catchment area of the rivers is between 1,000 and 10,000 km² and thus lies between that of the silicate or carbonate, fine to coarse material rich, low mountain range rivers and that of the gravel-shaped rivers .
Flora and fauna
The fauna and flora of the great rivers of the low mountain range is very species-rich due to the numerous different habitats and structures. Invertebrates such as the common barnacle , the brook mussel , the little dragonfly and various types of mayfly larvae and caddis-fly larvae are also present, as are various types of fish, including barbel , gudgeon , chub and rudd .
One of the most common aquatic plants in these rivers are the water cockfoot and many other plant species such as water stars and large spawning herbs . Also phytoplankton and aquatic mosses are relatively frequently.
Examples
source
- Profile of the river type 9.2 (PDF; 168 kB) on wasserblick.net , accessed on March 13, 2012