Hydrographic sections — Metropolis 2017 — BD Carthage

An elementary hydrographic section is a related portion of rivers, streams or canals that are homogeneous for relationships involving it, and for the attributes it carries. It corresponds to the axis of the bed of #x27;a river, d' a stream or a canal. These are: — in the national territory: — all main axes, including in zone d'estran to zero NGF and marsh areas. Bag bags, regardless of their length (minimum 20 metres), completeness is ensured for culs-de-sacs d'a length greater than one kilometre or belonging to a watercourse d'a length greater than one kilometre. — in addition to the main axis, the axes of the secondary arms or which delimit an island of' an area greater than 10 hectares when a water course is subdivided into several. — abroad: — all river sections that ensure continuity, upstream or downstream of the network of the national territory; — all sections of navigable canals; — important sections of rivers d'water. Network continuity is ensured when crossing plans of water, marsh areas, drainage, d' agglomerations. An elementary hydrographic section is represented by an arc. On the other hand, an arc can correspond to several elemental sections when there is an overlay of the rivers. The elements of the d'hydrography network are cut into portions with the same attributes. Changing the value of n'an attribute n' results in the creation of a section only if the new value remains the same over a length of d'at least 20 meters; otherwise, the previous section is extended. The elementary hydrographic section is characterised by a set of d'attributes managed by l'IGN: State, direction d' flow, width, nature, navigability, gauge, position relative to the ground. An elementary hydrographic section is not to be confused with the hydrographic section, a concept introduced by Circular No. 91-50. __Origin__ Updated by l'IGN following requests from Agences de l'Water according to an annual cycle. The consolidated version is then sent to the Sandre __Partner organisations__ Ash, Agence de l'eau Adour-Garonne, Agence de l'eau Artois-Picardie, Agence de l'eau Loire-Bretagne, Agence de l'eau Rhine-Meuse, Agence de l'Rhone-Méditerrannée water and Corsica, Agence de l'eau Seine-Normandie __Links annexes__ * [see scenario d' geographical exchange of the hydrographic reference](http://www.sandre.eaufrance.fr/urn.php?urn=urn:sandre:scenario-d-echanges-geographique:eth:FRA:::ressource:1:) * [see interactive dictionary online](http://id.eaufrance.fr/ddd/ETH/2002-1#TronconHydrograElt) * [see Dictionary & Hydrographic Reference (ETH)" on the Sandre website](http://www.sandre.eaufrance.fr/?urn=urn:sandre:notice:dictionnaire::theme:ETH:ressource:2002-1:::html) [See this page on geo.data.gouv.fr](https://geo.data.gouv.fr/fr/datasets/05ca9c8713d19f758d4acd9c37ce4a571b4f5ae5)