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Watercourse

Deadwood

Updated on 26/10/2022
Définition
Sens commun
Material gathering isolated trunks, branches, entire trees or accumulations of plant debris of heterogeneous sizes. Deadwood is a key element for changing channel forms and therefore diversifying environments. It also plays an important role as medium and substrate for vegetation and microfauna, but it can create jams after a flood. It serves as a shelter for the green lizard, the fragile slow worm, the common toad and the midwife toad. Sometimes hanging in the trees after several seasons, it can also serve as shelters for carnivores like the stone marten or the genet.
Source
According to OFB

Reach

Updated on 13/07/2018
Définition
Sens technique
Section of a watercourse or channel, usually between two interesting sections in land use planning. Originally, "reach" means a supply channel to a hydraulic structure. Applied to a watercourse, it must keep the nuance of particular stretch, with no fall or rapids.
Source
According to Marcel Roche (hydrologist)

River bank

Updated on 26/10/2022
Définition
Sens commun

Permanent edge of a watercourse, located above the normal water level. The river bank is characterized by its cross-sectional shape (gently sloping bank, steep bank), its composition (sand, marl), its vegetation (herbaceous, shrub. Frequently subject to overflow and erosion from the stream, the banks are habitats for many species. They allow the passage of discrete animals like water rat, muskrat, water shrew or the Pyrenean desman. Some changes in the water level allow boulders to appear and form excellent perches for the dipper. Sand martins enjoy the banks to do their nest. Crawfish, fish and macroinvertebrates use shelters on the banks to hide, breed or feed.

Source
According to OFB

Dam

Updated on 26/10/2022
Définition
Sens commun
Structure that crosses more than the low-water channel of a permanent or intermittent watercourse or a thalweg. We can also say that it bars up a river cachtment area. But a dam can be outside a watercourse. The reservoir it makes upstream is gravity fed by the river basin waters. The body of a dam can be made of earth, masonry, concrete, wood, metal, etc. There are several types of dams, according to their function: hydropower dam, reservoir dam, dam for pollution control, dam for navigation.
Source
According to OFB and IOWater

Silting up

Updated on 13/07/2018
Définition
Sens technique
Piles of earth, sand, gravel, pebbles brought by water and created by a decrease in flow velocity. This phenomenon is generated by the plant growth cycle that brings every year a litter layer (up to several tons per year). Much of this litter is very slowly changed into mineral salts by bacteria and microscopic fungi. Sediment inputs and vegetable deposits from outside add to the filling of the marsh thus acting as a biogeochemical buffer for the drainage basins.
Source
According to Forum of Atlantic Marshes

Anastomosed

Updated on 26/10/2022
Définition
Sens technique
Describes a set of intersecting channels in a wide floodplain, or a delta, well endowed with all kinds of distributaries and cut-offs separated by shoals. The term, borrowed from the medical language, is used in hydrology only as an adjective: we indeed speak of an anastomosed river
Source
According to OFB

Alluvium

Updated on 26/10/2022
Définition
Sens commun
All materials (pebbles, gravel, sand) deposited by running water in floodplains, especially during floods.
Source
According to OFB

Ecological flow

Updated on 13/07/2018
Définition
Sens technique
Minimum flow required to achieve ecological quality goals for associated surface waters. The value of this flow varies for each country.
Source
According to Eurostat