Drugeon
| Drugeon | ||
 Bridge over the Drugeon at Pontarlier |
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| Data | ||
| Water code | FR : U2030500 | |
| location | France , Doubs department | |
| River system | Rhône | |
| Drain over | Doubs → Saône → Rhône → Mediterranean | |
| Headwaters | Vaux-et-Chantegrue | |
| Source height | 864 m | |
| muzzle | at Tout Vent in the Doubs coordinates: 46 ° 56 '42 " N , 6 ° 21' 38" E 46 ° 56 '42 " N , 6 ° 21' 38" E |
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| Mouth height | 800 m | |
| Height difference | 64 m | |
| Bottom slope | 1.8 ‰ | |
| length | 35.5 km | |
| Left tributaries | Ru de Chantegrue, Lotaud | |
| Right tributaries | Bief Belin | |
The Drugeon is a 35.5 km long left tributary of the Doubs in the catchment area of the Rhone , in the French department Doubs in the Bourgogne-Franche-Comté region . The river name is probably derived from the Gallic word dubron (water). The middle and lower reaches of the river, together with the surrounding moor areas, are designated as Natura 2000 protected areas.
geography
The source of the Drugeon is located at 864 m above sea level in the High Jura in a valley basin with a marshy lowland east of the village of Chantegrue (municipality of Vaux-et-Chantegrue ). A few hundred meters after the source, the Drugeon flows from the south-west to the Ru de Chantegrue and from the north-east to the Bief Belin , both of which are short side streams that arise on the surrounding mountain ranges. The Drugeon leaves the Vaux basin to the northwest and enters a clus cut into an anticline of the Jura folds . The relatively narrow, up to 200 m deep gorge separates the Montagne du Laveron in the north-east from the Haute Joux chain in the south-west. The Klustal is followed by the Départementsstraße ( Frasne - Labergement-Sainte-Marie ) and the railway line from Frasne via Vallorbe to Lausanne .
In the Klus, the Drugeon first turns to the west before reaching the second Jura plateau at Bonnevaux . Here it draws a sharp arc and now flows in a south-west-north-east direction in accordance with the direction of the Jura Mountains in this region. It crosses the wide Arlier plain between Pontarlier and Frasne, which is 820 m on average and is also known as the Bassin du Drugeon . In this area it flows through the localities of Bouverans , La Rivière-Drugeon , Bannans , Houtaud , Dommartin and Vuillecin . At an altitude of 800 m on the northeastern edge of the plain, the Drugeon flows into the Doubs below the Tout Vent farm, 5 km north of Pontarlier. With an average gradient of around 0.2%, the river has an extremely small gradient between its source and its mouth.
The few short side streams of the Drugeon include the outflow of the Lac de l'Entonnoir (also Lac de Bouverans , fed by a karst spring), the Lotaud from the Étang de Frasne , the Bief Voulain and the Bief Rouget .
geology
The Drugeon flows in a valley that was created by a prehistoric course of the Doubs. The source of the Drugeon is only three kilometers from the current course of the Doubs near Labergement-Sainte-Marie. A saddle, the lowest point of which is at 865 m, leads from the Drugeon source practically flat over to the Doubs valley above Lac de Saint-Point , which is here at 850 m.
The Bassin du Drugeon in the plain northwest of the Laveron anticline follows a syncline structure that is filled with Cretaceous and Tertiary deposits. The ice age glaciers shaped the area and deposited moraine material. The subsoil was sealed and impermeable to water by the fine layer of clay and silt, which is why an extensive bog plain has been able to form since the retreat of the glacier (around 8000 BC).
Hydrology
The catchment area of the Drugeon covers an area of 191 km², according to other sources 170 km². The Drugeon has a pluvio-nival runoff regime with strongly fluctuating water levels. At the Vuillecin station just before it flows into the Doubs, the mean annual runoff is 3.29 m³ / s. The bandwidth of the runoff amounts from 0.15 m³ / s in the course of long dry periods up to 70 m³ / s. The highest amounts of runoff are usually recorded in the months of February to April during the snowmelt and in the summer half-year with heavy thunderstorm rain. In the catchment area of the Drugeon, an average annual rainfall of around 1460 mm falls. According to scientific studies, 42% of this flows off via the Drugeon, 35% evaporates directly back into the atmosphere and the remaining 23% seeps into the subsurface, from which the significantly lower-lying sources of Ain in the west and Loue in the north benefit.
use
Several sawmills between Vaux and Bonnevaux, as well as various mills, have been using the Drugeon's hydropower since ancient times. As early as the 18th century, efforts were made to drain the bog area near Bouverans. In the period between 1959 and 1973, the course of the Drugeon below Bonnevaux to its confluence with the Doubs was corrected and straightened and the surrounding moors were drained with the aim of gaining around 2000 hectares of arable land. Despite the efforts, only around 200 hectares of fertile land were gained.
Nature reserve
From 1997 to 2002 the course of the Drugeon river was renatured over large stretches, with the numerous former meanders being re-integrated and the moor areas close to the river being restored. Furthermore, it was about the improvement of the water quality and the restoration of the habitats for fish and other aquatic animals. In 2004, the Bassin du Drugeon with an area of 67 km² was included in the series of Natura 2000 protected areas.
Individual evidence
- ↑ sandre.eaufrance.fr
- ↑ Banque Hydro - Station U1235020 - Drugeon
- ↑ Le réseau Natura 2000 - Bassin du Drugeon ( Memento of the original from January 29, 2010 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
Web links
- Documentation on dismantling, PDF , French Ministry of the Environment