Sand-shaped lowland stream
The sand-shaped lowland stream is a flowing water type (type 14) of the north German lowlands defined by the Federal / State Working Group on Water (LAWA) .
It is characterized by various features:
Water structure
The bottom consists mainly of sand, with smaller proportions of gravel or organic material. The water profile is naturally flat, the course of the stream meanders relatively strongly. Impact and sliding slopes are usually pronounced, but there are hardly any river banks. It can in the water environment to fen formations come when the valley is correspondingly flat. There is an alternation between longer, calm sections and short areas with faster currents, for example at deadwood barriers.
Sand dominated lowland streams are mostly in shallow well or sole valleys in the area of Sander or moraines to find. By definition, their catchment area is between 10 and 100 km².
Flora and fauna
Most of the animal species that occur in streams of this type do not colonize the sandy part of the bed, but mainly the littered gravel banks or other structures such as dead wood . Examples are the larvae of some stonefly species , some caddis fly larvae and fish such as the nine-spined stickleback or, in streams with pronounced gravel banks, the brown trout . In general, the smaller, sand-shaped streams in particular are rather poor in species.
The macrophytes are also largely absent , especially in the area of the young moraines. In other areas, for example, the watercress can occur. In the bank area there are partly reed beds . Plankton is usually absent in the streams.
Examples
Web links
- Profile of river type 14 (PDF; 9.3 MB) Federal Environment Agency, accessed on April 9, 2019 .
- Water type of the year 2018 - sandy lowland stream. Federal Environment Agency, accessed on February 22, 2018 .