# Alluvial zones of national importance (AU) A thematic map of the Atlas of Switzerland, the national atlas published by ETH Zurich. The map is drawn in the browser; this file describes it and lists its variants and links, but not the data values shown on the map. - Map: https://atlasderschweiz.ch/en/theme/alluvial-zones-of-national-importance-au/ - Short title: Alluvial zones (AU) - Map id: 360 - Categories: Landscape and Space › Landscapes/Habitats › Protected areas - Keywords: Hydrology, Nature conservation - Published: 2010-11-26 - Last revised: 2021-06-25 - Content language: English - Other languages: [Deutsch](https://atlasderschweiz.ch/de/thema/auengebiete-von-nationaler-bedeutung-au.md), [Français](https://atlasderschweiz.ch/fr/theme/zones-alluviales-dimportance-nationale-za.md), [Italiano](https://atlasderschweiz.ch/it/tema/zone-golenali-dimportanza-nazionale-zg.md) ## Description Alluvial zones are formed when the water from mountain streams, rivers and lakes comes in contact with the ground. Rivers and streams change their course and sometimes flow over their banks when the water level rises. Therefore, alluvial zones change constantly, as a result of the alternation of flooding and low water, and of erosion and sedimentation. These dynamics generate a mosaic of extremely different environments: water courses, dead channels, sandbars, and levees of dry gravel, herbaceous pioneer formations of bushy or tree-like willows and high, dense, impenetrable forests. Within a small area (0.55% of the national territory), alluvial zones provide a habitat for a multitude of plants and animals. The federal inventory of alluvial zones of national importance currently comprises 283 sites covering a total area of approximately 226 km² (2015). In the Alps, above the tree line, glacial forelands (zones of glacial retreat) and alpine alluvial plains are to be found. At lower altitudes of the Jura, of the Central Plateau and of the Alps one mainly finds alluvial zones along watercourses, but also in some deltas and along the banks of lakes. Numerous alluvial zones in the inventory have been transformed by human activities. The Ordinance on the Protection of Alluvial Zones of National Importance was brought into force by the Federal Council on 15 November 1992. ## Sources - Auenberatungsstelle Yverdon/Services conseil Zones alluviales Yverdon: Auen - BAFU/OFEV/UFAM/FOEN (2015): [Auen](http://www.bafu.admin.ch/biodiversitaet/13721/14385/14438/14442/index.html?lang=de). Bundesamt für Umwelt ## Data sources - FOEN (2009): [Bundesinventar Auengebiete (AU)](http://www.bafu.admin.ch/biodiversitaet/13690/13725/16022/index.html?lang=de) ## Data owners - [Swiss Federal Office for the Environment (FOEN)](http://www.bafu.admin.ch/) ## Citation The terms of use ask to name the Atlas of Switzerland and the data owners, and to keep the source references in exports, screenshots and embeds. Cite the map as: > Atlas of Switzerland (2021): Alluvial zones of national importance (AU). ETH Zürich. Map data © FOEN. https://atlasderschweiz.ch/en/theme/alluvial-zones-of-national-importance-au/ ## Links The map opens at its full extent; a link cannot set the map position. - Map: https://atlasderschweiz.ch/en/theme/alluvial-zones-of-national-importance-au/ - Short link, stays valid when the title changes: https://atlasderschweiz.ch/en/t/360/ - Side by side with another map: https://atlasderschweiz.ch/en/comparison/?lt=360&rt={id of the other map}&ru={u of the other map, or leave out} Embed in another website (allowed by the terms of use, as long as the source references stay visible): ```html ``` In the embed URL, `dm` sets what is shown: `e` the map with its title bar (default), `p` also the values of an object clicked on the map, `m` only the map with a button that opens it in the atlas. `ig=1` (default) lets the map react to scrolling and dragging only after a click into it, `ig=0` right away. The size can be changed in `style`. For the use and citation of maps and data, see the [terms of use](https://atlasderschweiz.ch/en/terms-of-use/).