Möhlin (Rhine)
Möhlin | ||
The Möhlin in Breisach |
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Data | ||
Water code | EN : 2336 | |
location | Baden-Wuerttemberg , Germany | |
River system | Rhine | |
Drain over | Rhine → North Sea | |
Headwaters | Above Sankt Ulrich in the Black Forest from several hillside debris sources | |
Source height | approx. 1080 m above sea level NHN | |
muzzle | In Breisach in the Rhein , Rhein-km 225.3 coordinates: 48 ° 1 '31 " N , 7 ° 34' 48" O 48 ° 1 '31 " N , 7 ° 34' 48" O |
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Mouth height | 189 m above sea level NHN | |
Height difference | approx. 891 m | |
Bottom slope | approx. 28 ‰ | |
length | 32 km | |
Catchment area | 218.9 km² | |
Discharge at the Oberamhaben A Eo gauge : 43 km² Location: 20 km above the mouth |
NNQ MNQ MQ Mq MHQ |
10 l / s 100 l / s 660 l / s 15.3 l / (s km²) 8.71 m³ / s |
Left tributaries | New stomach | |
Small towns | Bad Krozingen, Breisach | |
Communities | Bollschweil, Ehrenkirchen |
The Möhlin is a small, 32 km long tributary of the Rhine in the area of the Breisgau-Hochschwarzwald district . The name is possibly of Celtic origin; there is archaeological evidence of an oppidum at a tributary of the Möhlin.
course
The Möhlin rises on the western roof of the Schauinsland massif above Sankt Ulrich in the Black Forest from several slope debris sources. The main spring is located about 500 meters northeast of Gießhübel at 1080 m above sea level. NN. In the course of time, the river has cut into the anatexite and formed a steep notch valley with an average gradient of around 12 °. It flows in a north-westerly direction and after 200 meters it is passed under the county road K 4957.
The near-natural upper course flows through Bollschweil at the foot of the Black Forest and reaches the Rhine plain near Ehrenkirchen . When the Möhlin emerges from the mountains into the Rhine plain, it loses water through seepage. Depending on the runoff, infiltration accounts for up to 15% of the total volume. The course of the river is already heavily canalised in the area of the city of Bad Krozingen , just above the district of Biengen, where the Neumagen , which is mostly more watery, flows into the Möhlin. With the construction of the Breisach cultural weir in 1965, the original mouth was moved below the weir.
The wing dam of the Rhine side dam crosses the Möhlin about 600 meters across the Rhine. A weir with a clear opening of 18 meters with a segment lock has been built at the crossing point in the Möhlin. In the event of a disaster, around 500 m³ / s must be discharged through the Möhlin weir. The estuary of the Möhlin below the weir therefore had to be expanded to 1.8 km in length for this discharge. In addition to discharging the disaster floods, the Möhlin weir has the task of using the movable lock above the weir to create the most favorable water levels. So that the Möhlin, which has been developed for a discharge of 500 m³ / s, does not drain the groundwater that is to be raised by the culture weir, a fixed threshold with a fish ladder was installed 400 m above the mouth of the Möhlin into the Rhine. The height of the threshold has been chosen so that an optimal water level above the threshold can be guaranteed.
Not least because of the intensive agriculture in the Rhine valley, the Möhlin falls dry on its middle course in hot summers. Conversely, the rather tranquil river can swell dangerously during heavy rainfall or sudden snowmelt.
Web links
- Map of the course and catchment area of the Möhlin on: State Institute for the Environment Baden-Württemberg (LUBW) ( information )
Individual evidence
LUBW
Official online waterway map with a suitable section and the layers used here: Course and catchment area of the Möhlin
General introduction without default settings and layers: State Institute for the Environment Baden-Württemberg (LUBW) ( notes )
- ↑ a b Height according to the contour line image on the background layer digital topographic map or according to the digital terrain model of the online waterway map.
- ↑ Length according to the waterway network layer ( AWGN ) .
- ↑ Catchment area after the layer aggregated areas 04 .
Other evidence
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↑ Flood forecast center , State Institute for the Environment Baden-Württemberg MHQ at Abfluss-BW - a data and map service of the State Institute for the Environment Baden-Württemberg ( information )