Ried (landscape in Alsace)
The Ried is an Alsatian landscape. It consists of pastures that are regularly flooded, and also of gallery forests , whose vegetation is lush. The Petit Ried in the north and the Grand Ried in the south shape the landscape along the Rhine and Ill , between Lauterbourg and Sélestat . The Rhine regulation has had a negative impact on this landscape. Since the Rhine, wedged between the dykes, can no longer spread the sediments as it used to, and has a much higher flow velocity, it digs deeper and deeper into the layers of gravel below. As a result, the groundwater level sank and the water reservoirs previously supplied by the Rhine ran in the opposite direction into the Rhine. The soils of the pastures have become much drier as a result.
Toponymy
The word reed is related to the German word reet and the English reed and means reed.
geology
In the course of the Quaternary , when the Rhine Rift continued to sink, the plain was filled with alluvial sediments. They came from the Vosges , but mostly from the Alps . The thickness reaches 75 m in Strasbourg , 150 in Mulhouse and 250 m in Neuf-Brisach . The sand from the Vosges has a high content of tourmaline, while the sand from the Alps is characterized by a combination of heavy minerals (hornblende, epidote and garnet).
Due to the porosity of the rock, the Upper Rhine has the largest groundwater reservoir in Europe.
Web links
- Map of the Ried ( French )
- Groundwater website Aprona.net ( French )
- Kies des Rheins Website Association Strasbourgeoise des Amis de la Minéralogie 67 ( French )
Individual evidence
- ↑ Etymology from the English reed
- ↑ Jean-Claude GALL, Alsace, the fossil et des hommes.
- ^ Jean-Paul von Eller, Vosges Alsace guides géologiques régionaux .