Hydroecoregions Level 1 (HER-1)

A homogeneous spatial entity in terms of the physical determinants that control the overall organisation and functioning of aquatic ecosystems. At the basin level, the universally recognised primary determinants of the ecological functioning of rivers are geology, terrain and climate. This concept is based on hierarchical control theories of hydrosystems, and is based particularly on the combination of physical scales, from the basin to the microhabitat. IRSSEA (formerly CEMAGREF) has defined hydroecoregions for metropolitan France. He developed the conceptual framework for regionalisation by “hydroecoregion” and the general aspects of the method, with the aim of defining and characterising Hydroecoregions for metropolitan France. There are two levels for hydroecoregions (HER): level 1 and Level 2. A total of 22 Level 1 Hydro-Ecoregions (HER-1) were identified on criteria combining geology, terrain and climate, universally considered as the primary determinants of the functioning of running water ecosystems on a 1/1,000,000th scale. The method and results are described on the Quantitative Hydroecology Laboratory website (see section Source online)