Hydromorphology
Heterogeneity of the low-flow channel
Définition
Habitat
Définition
Sens technique
Environment defined by specific abiotic and biotic factors in which a species lives at any stage of its life cycle. A natural habitat is distinguished by geographic, abiotic and biotic entirely natural or semi-natural.
Source
according to European Commission
Geomorphology
Définition
Sens commun
Science that studies the landforms and their mobility and dynamics. In hydrosystems, the analysis focuses on the geometry of the riverbed and on the causes of its spatial (from upstream to downstream) or time-slot transformations in connection with the modification of solid and liquid flows, the dynamics of Source
According to Rhone-Mediterranean and Corsica Water Agency
Spawning
Définition
Sens commun
A place for the reproduction of fish, amphibians, molluscs and crustaceans (they lay their eggs there). Gravel bars, oxbows, alluvial forests, floodplains, tree roots are the spawning. Each species, according to its reproductive strategy, is breeding in a particular habitat.
Source
According to OFB
Facies
Définition
Sens technique
Morphodynamic unit of a stream having longitudinal homogeneity in the slope of the water surface and in the distribution of water levels, in the velocities of the flow and in the particle size of the substrate. The length of a facies can vary from one to several times the width of the wet bed. For example, we can mention three major types of contrasted facies: wet (relatively low slope, high water levels, low velocities); fast (high slope, high flow velocities, substrate mainly composed of large blocks ); and flat (average slope, average and uniform velocities, water level rather low, symmetrical and regular cross profile, medium and homogeneous particle size).Source
According to Cemagref
River mobility area
Définition
Sens technique
Area of the floodplain within which the riverbed can move in accordance with the decree of 24/01/2001 relating to the exploitation of quarries. The river is a dynamic system, moving in space and time: it constantly adjusts to fluctuations in the liquid flow. These adjustments result in lateral translations allowing the mobilization of sediments and the functioning of aquatic and terrestrial ecosystems. The mobility Source
According to Cemagref
Progressive erosion
Définition
Sens commun
Mechanism of sinking the riverbed propagating itself downstream. The starting point of progressive erosion is an action, often human, causing a deficit of alluvial materials (construction of a dam or a sill, abstraction of Source
According to Cemagref
Erosion of river banks
Définition
Sens commun
Natural phenomenon, usually caused by the current, involved in the transport of sediment load and sediment recharge of streams. The erosion of river banks is causing migration of meanders, and ensures the dynamic functioning of the
Source
According to OFB