Orbe (river)

	Orbe
	Course of the orbe
	Data
Water code	FR : V2400900 , CH : 3229
location	Jura Mountains France Bourgogne-Franche-Comté Jura department; ; Switzerland Canton of Vaud Jura-Nord vaudois district ; ;
River system	Rhine
Drain over	Thielle → Zihl Canal → Aare → Rhine → North Sea
source	in France in the Jura Mountains near Les Rousses , near the Swiss border ; 46 ° 29 ′ 31 ″ N , 6 ° 3 ′ 31 ″ E
Source height	1100 m
confluence	with the talent for Thielle to Orbe Coordinates: 46 ° 44 ′ 15 " N , 6 ° 33 ′ 47" E ; CH1903: 533 091 / 176 634 46 ° 44 '15 " N , 6 ° 33' 47" O;
Mouth height	435 m above sea level M.
Height difference	665 m
Bottom slope	10 ‰
length	63.5 km
Catchment area	346 km²
	source
	muzzle
	Source and mouth of the Orbe
	The Orbe about 500 m below the Source de l'Orbe

The Orbe (dt. Formerly Orbach ) is the 64 km long, left and western headwaters of the Thielle (dt. Zihl ) in the Jura department in France and in the canton of Vaud in Switzerland . After Orbe it unites with the talent for Thielle, which flows into Lake Neuchâtel at Yverdon-les-Bains . Its catchment area is 346 km².

geography

course

source

The Orbe rises in France in the Jura Mountains. Its source is in the Haut-Jura Regional Nature Park on the northern edge of the village of Les Rousses at an altitude of around 1100 m , nestled between the Risoux ( 1419 m ; France) in the north-west and Noirmont ( 1568 m ; Switzerland) in the south-east. The border between France and Switzerland runs about 3 km southeast of the source at the northwest foot of Le Noirmont .

Upper orbe

The Orbe reaches the Lac des Rousses , a lake at an altitude of 1058 m , after just under 2 km . After this lake, the stream flows northeast in the wide high valley of Vallée de Joux . It is accompanied on the left, northwest side by the wooded heights of the Risoux, on the southeast side by the chain of Mont Tendre ( 1679 m ).

After about 5.6 km as the crow flies, the Orbe passes the state border. From now on it runs in western Switzerland, and after another 10 km it flows into the Lac de Joux . Due to its many small meanders , the flow path measures almost exactly 22 km for this 15.6 km as the crow flies. On the stretch between the two lakes, the river overcomes a gradient of only 50 m. Approximately from the northeast end of Lac de Joux, it flows a few meters into Lac Brenet, which is only two meters lower . There the water seeps away through a system of fissures at the bottom of the lake and only reappears 2.5 km north-northeast in the Source de l'Orbe .

Source de l'Orbe

The karst spring of the Orbe

The Source de l'Orbe (Eng. Source of the Orbe ; ⊙ ) is located at 780 m above sea level on the western edge of the Vallorbe basin . The discharge of the karst spring fluctuates between 2000 l / s at low water levels and 80,000 l / s at high water. In 1974 the limestone cave Grottes de l'Orbe behind this spring was opened to the public by digging a tunnel. The cave system is one of the most important natural attractions of the Jura. Here you can see the sinter deposits and the underground course of the Orbe. The Orbe rises directly from a rock face. 46.698144444444 6.3454055555556

Lower orbe

Below Vallorbe there is a barrage of the Orbe. The only notable tributary, the Jougnena, flows here from the left . Then the Orbe turns to the east and flows in a deep valley with several waterfalls ( Gorges de l'Orbe ; ⊙ ) to the Swiss Central Plateau . It has not typical here Jura transverse valley formed, rather, the river follows a geological fault zone which crosses the longitudinal chains and their parts has shifted to today. 46.720604627778 6.4061313408333 725

After the Gorges de l'Orbe, the river curves around the hill on which the old town of Orbe is located, and then steps out into the Plaine de l'Orbe at the foot of the Jura. From here on the Orbe is canalized.

confluence

From the exit of the Orbe at the grotto to the confluence ( 435 m ) with the Talent two kilometers northeast of the Orbe VD , the flow path is again 22 km. With this confluence the now canalized Thielle (Ger. Zihl , GEWISS no. 207) begins . This flows through Lake Neuchâtel and from there into Lake Biel , now known as the Zihl Canal . Since the Aare has been routed through Lake Biel, the Zihl flows into the largest Swiss Rhine tributary as soon as it reaches that lake. Before that it flowed to Meienried .

Catchment area

The 345.71 km² catchment area of the Orbe lies in the Jura Mountains and is drained to the North Sea via the Zihl , the Aare and the Rhine .

It consists of 52.7% wooded area , 29.4% agricultural area , 3.5% settlement area , 3.5% water area and 1.0% unproductive areas.

The mean height of the catchment area is 1125 m above sea level. M. , the minimum height is 435 m above sea level. M. and the maximum height at 1678 m above sea level. M.