Aar

This article is about a river in Switzerland. For other uses, see AAR (disambiguation) and Aare (disambiguation).

Aar
The Aar at Bern
Drainage basin of the Aar
Origin	Canton of Bern, Switzerland
Mouth	Rhine
Basin countries	Switzerland, France
Length	295 kilometres (183 mi)
Basin area	17,779 km2 (6,865 sq mi)

The Aar (German Aare), a tributary of the High Rhine, is the longest river that both rises and ends entirely within Switzerland.

Its total length from its source to its junction with the Rhine comprises about 295 km (183 miles), during which distance it descends 1,565 m (5,135 ft), draining an area of 17,779 km² (6,865 sq mi), including the whole of central Switzerland.

Course

The Lower Aar Glacier

The Aar at Innertkirchen

Inside the Aar Gorge

The Aar rises in the great Aar Glaciers of the Bernese Alps, in the canton of Bern and west of the Grimsel Pass. It runs east to the Grimsel Hospice, below the Finsteraarhorn, and then northwest through the Haslital, forming on the way the magnificent Handegg Waterfall, 46 m (151 ft), past Guttannen. Between Innertkirchen and Meiringen, the river carves through a limestone ridge in the Aar Gorge or Aareschlucht.

A little past Meiringen, near Brienz, the river expands into Lake Brienz. Near the west end of the lake it receives its first important tributary, the Lütschine. It then runs across the swampy plain of the Bödeli between Interlaken and Unterseen before flowing into Lake Thun.

Near the west end of Lake Thun, the river receives the waters of the Kander, which has just been joined by the Simme. On flowing out of the lake it passes through Thun, and then flows through the city of Bern, passing beneath eighteen bridges and around the steeply-flanked peninsula on which the Old City is located. The river soon changes its northwesterly flow for a due westerly direction, but after receiving the Saane or Sarine it turns north until it nears Aarberg. There, in one of the major Swiss engineering feats of the 19th century, the Jura water correction, the river, which had previously rendered the countryside north of Bern a swampland through frequent flooding, was diverted by the Hagneck Canal into the Lake of Bienne. From the upper end of the lake the river issues through the Nidau-Büren channel and then runs east to Büren. The lake absorbs huge amounts of eroded gravel and snowmelt that the river brings from the Alps, and the former swamps have become fruitful plains: they are known as the "vegetable garden of Switzerland".

From here the Aar flows northeast for a long distance, past the ambassador town Solothurn (below which the Grosse Emme flows in on the right), Aarburg (where it is joined by the Wigger), Olten, Aarau, near which is the junction with the Suhre, and Wildegg, where the Hallwiler Aa falls in on the right. A short distance further, below Brugg it receives first the Reuss, and shortly afterwards the Limmat. It now turns due north, and soon becomes itself a tributary of the Rhine, which it surpasses in volume when the two rivers unite at Koblenz (Switzerland), opposite Waldshut, Germany. The Rhine, in turn, empties into the North Sea after crossing into the Netherlands.

Tributaries

At the "Wasserschloss", where the rivers Aar, Reuss and Limmat come together

The convergence of the Aar and the Rhine at Koblenz

• Limmat
  • Sihl
  • Linth (main tributary of Lake Zürich)
• Reuss (see also: Reuss (river)#Tributaries)
  • Kleine Emme
  • Sarner Aa
  • Engelberger Aa
  • Schächen
  • Furkareuss
• Suhre
• Bünz
  • Aabach
• Wigger
• Emme
• Zihlkanal
  • Suze
  • Broye
  • Orbe
• Saane (Sarine)
  • Sense
• Kander
  • Simme
  • Allenbach
• Lütschine

Reservoirs

• Lake Wohlen, 481 m
• Niederriedsee, 461 m
• Klingnauer Stausee, 318 m
• Lake Brienz
• Lake Thun
• Lake Biel

History

The river's name may be attested to in the Gaulish (Helvetic) Berne zinc tablet which dates back to Roman Gaul. Its Roman name was Obringa.

External links

• The Aar Gorge (Aareschlucht)
• Texts on Wikisource:
  • "Aar". The Nuttall Encyclopædia. 1907. 
  • Chisholm, Hugh, ed. (1911). "Aar". Encyclopædia Britannica (11th ed.). Cambridge University Press. 
  • "Aar". Collier's New Encyclopedia. 1921.