[IRSTEA] Hydro-écorégions de niveau 2

Regional typology of running water and reference stands of invertebrates. Elements for the implementation of the European Framework Directive on Water. The objective of the European Framework Directive on Water of 23 October 2000 is to achieve ‘good environmental status’ for all aquatic environments within 15 years.The implementation of this Directive requires the establishment of a typology of watercourses, in order to define the ‘reference conditions’ for each type of medium, to carry out an inventory of water bodies and then to draw up a programme of operational measures. 22 level 1 hydro-ecoregions (HER-1) have been identified on criteria combining geology, topography and climate, universally considered as primary determinants of the functioning of running water ecosystems. These HER-1, together with a longitudinal description of the network from Stralher rows, provide the basis for the typology required for the implementation of the Directive. A second level of regionalisation is also defined, resulting in a quantified description of about one hundred hydro-ecoregions at level 2 (HER-2). These HER-2 serve to clarify the internal variability of HER-1. The analysis of benthic invertebrates stands very well validates the hydro-ecoregion approach. The typology of running water by hydro-ecoregions is a robust, operational and scientifically based approach for the implementation of the European Framework Directive on Water. The method of regionalisation by ‘hydro-ecoregions’ developed for France has been implemented at European level using the same conceptual basis. For further information: http://www.irstea.fr/la-recherche/unites-de-recherche/maly/pole-onema-irstea/regionalisation-et-typologie/les-hydro The layer contains a geometric error (Ring Self-Intersection) according to the CHG standard