Hydromorphology

Ratio between the total length of the watercourse in a river basin and the surface area of the latter. Drainage density is expressed in km/km2.

Form indicating the overall configuration of the water body. It can be of the following types: "L", in the case of shallow lakes with thermal stratification of little extent and/or unstable (polymictic lakes) and a heavily dominant coastal zone; "P" in the case of deep lakes with a stable thermal stratification (monomictic or dimictic lakes) and a reduced coastal zone; "LP" in the case of lakes with both a stable stratified deep zone (monomictic or dimictic) and a wide coastal area, the

According to the SDAGE and Order of 22 September 1994, this means removing alluvial deposits accumulated on the riverbed. Indeed, Article 11 of the Decree of 22 September 1994 provides that the extraction of materials in the riverbed of watercourses and bodies of water crossed by streams is prohibited. If extraction of alluvial materials is necessary for duly justified maintenance, or for the development of a watercourse or a

Difference between the average water depth of rainfall in the basin and the equivalent depth of runoff. It can be considered, in a first approximation, as actual evapotranspiration.

All operations to cover a space with vegetation, grass, shrubs or trees.

Any material used to be a physical carrier for organisms.

Action of enabling the return to the previous status of an ecosystem degraded by neglect, or the purposive control of human action.

Passage abnormally used or created by water in a dike, a dam.

Regulations that govern the operation of dams and hydraulic systems in general. Since 1995, they have been approved by the prefecture and established after public inquiry. They give rules for the management of structures (minimum flow, reserved flow, water release, etc). Regarding structures for the replenishment of low-water flow (in normal and crisis situation), they must determine how water resources will be shared between