Elementary hydrographic sections — Meeting 2012 — BD Carthage

An elementary hydrographic section is a related portion of rivers, streams or canals that is 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. The geometry is close to the BDTopo IGN which was used for its realisation.The BDCarthage Réunion is maintained by the DEAL Réunion.The BD Carthage Réunion is a version validated by the SIE but not by the \#x27;IGN and that therefore problems of incompatibility with IGN referentials can occur (and that#x27; an update &officialiseraquot; the Carthage comic with IGN validation). __Origin__ The BDCarthage Réunion is maintained by DEAL Réunion. __Partner organisations__ Ash, DEAL Réunion __Links annexes__ * [see documentation on Sandre website](http://www.sandre.eaufrance.fr/?urn=urn:sandre:dictionnaire:ETH::entite:TronconHydrograElt:ressource:latest:::html) * [see Dictionary & Hydrographic Reference (ETH)" on the Sandre website](http://www.sandre.eaufrance.fr/?urn=urn:sandre:notice:dictionnaire::theme:ETH:ressource:latest:::html) [See this page on geo.data.gouv.fr](https://geo.data.gouv.fr/fr/datasets/4a9e15b87beaa92f7222f35661f00b77c8f2e9e3)