Aar

The Aare in Bern Berner Munster

The Aare (French Aar / Arole; Latin Arula / Arola / Araris ) is the longest running entirely within Switzerland flow. It is also the quantity of water, by far the largest tributary of the Rhine before the Meuse and brings together more water than Mosel and Main. The total length of the river Aare is 288 km, the slope 1565 m, its catchment area 17,620 km ² and average discharge 560 m³ / s

Course

The Aare rises the Aargletschern ( Oberaar and Unteraargletscher ) in the Grimsel area a few miles south of Guttannen happens Innertkirchen and crosses the Aare gorge deeply incised above Meiringen in the Haslital.

When it empties into Lake Brienz Brienz. The Aare river then flows through the so-called Bödeli, with Interlaken as its most famous place. Then they crossed the Lake of Thun, where it picks up the Kander.

In the Thun Lake Thun and Aare leaves the flows through the wide Aare Valley between Münsingen and the Belpberg to Bern. In Belpmoos the Gürbe and Pour meet together and lead together with the Aare. In Bern Aare makes a tight arc around the old town built on a outcrop. With an existing since the Middle Ages long barrage, the threshold, a short channel Tych derived. A bit further down the river Aare flows around similarly cornered peninsula before it is jammed in Wohlensee to generate electricity.

After the confluence of the River Sarine at Oltigen south of Aarberg the Aare flowing through the artificial Hagneck channel and at Hagneck into Lake Biel. In Nidau it leaves the lake of Biel by the Nidau- Buren - channel so that it meets again on her old riverbed Buren. The route of the original river course between Aarberg and Bueren an der Aare, the so-called Old Aare, forms a natural state wide area which is north of the canal complemented by the wide, cut in the Fluvial Altlauf the so-called Häftli. The Aarestrecke of Nidau to Solothurn, like the navigable Lake Biel.

From Bueren an der Aare Aare flows into the a vast plain, which was created by the silting up of the Solothurn lake called at the end of the last ice age, the Jura along northeast through Solothurn to Luterbach where the Emme flows. It flows past Wangen an der Aare, Bannwil, Aarwangen, Wolfwil, Murgenthal, Aarburg, Olten and Aarau and in a clammy like Klus by Brugg. Then she takes on short succession Reuss and Limmat. This area is moated castle in Switzerland called because there unite three of the most water-rich rivers of Switzerland. The scenery right of the Aare between Thun and Aarwangen belonged since the Middle Ages to the country Comté. 60 communities in urban Aarau, Olten and Zofingen formed around 2005 a regional partnership under the name Aare country around the city of Aarau network / Olten / Zofingen.

From Brugg on the river Aare near Stilli flows through a wide Klus in the Jura to the north. Between the district Felsenaustrasse the community Leuggern and Koblenz (CH) opposite Waldshut ( DE) it flows into the Rhine. The Aare is 560 m³ / s of water -rich river (Rhein: 439 m³ / s); from hydrological point of view, ie the Rhine, a tributary of the River Aare, not vice versa. For the distance from Biel to Koblenz the Aare requires a flow time of about two days at average water level.

History of the river system

The Aare is characterized by the detectable for about 30 million years drainage line of the foreshore sink in the north of the uplifting Alps in their stretched north-east facing lower barrel section. After the tumultuous filling and eventual raising of the former narrow Helvetmeeres the area drained changing either west or east, until it turned out was the upper river system in the ancient Danube in the Pliocene million before 3 to 4 years. For a time, was his main source river even the upper Rhone. In the younger Pliocene those Aare- Danube broke the Burgundian Gate from back and made as Aare Sundgaustrom the main strand of the Ur -Rhone. At the end of the Pliocene the Talwasserscheide was cross dropped so far today Upper Rhine Graben near the former imperial chair volcano that the current outbreak again and became the main strand of the rapidly expanding Rhine - system. It was only about 800,000 years, the Alpine Rhine, then the main strand of the remaining Danube, diverted to today's high- Rhine Valley to the west, probably composed of the first major Pleistocene glaciations of the Alpine foothills.

Thus, the Aare was the chief hydrological main strand of all three North alpine stream systems throughout its history.

Use and cultural history

Since ancient times the river was with some of its tributaries to the waterway. In the Middle Ages it was an important border river: She separated eg the tribal duchies of Burgundy and Alemannia, was the boundary portion of the Carolingian Empire divisions and also separated for a while Hochburgund from the Holy Roman Empire. With the founding of the city of Bern at the end of the 12th and 13th century changed the character of the Aare, because by the mid -13th century there were bridges over the river and developed contiguous dominions on either side of the river Aare.

The short cross-border sections, the seemingly unmotivated differ from Aarebett today are due to the previous natural meanders, the time, had yet set the boundaries and are now fallen dry. In the 19th century, flourished in the area where the river Aare the timber floating; as a souvenir of Flösserweg was established between Stilli and walking castle. Long-distance transport on the river was not until the end of the 19th century to a halt, after the construction of railway lines and the first river power plants.

In modern times, the Aare has a high recreational value. You can navigate on long drives with the dinghy. Your bank is not very rugged, so you can safely swim in it in spite of the places pretty high flow. The water temperature in Berne shows a typical diurnal cycle. It increases throughout the day to a degree. This reflects the warming on the route from Lake Thun reflects up to Bern. In addition, temperature changes of more than 5 ° C can be observed during a few hours. Presumably, they depend on the wind conditions on Lake Thun, which deep water is transported from the lake to discharge.

Extension

In several sections of the river course was changed by large construction activities. Since the 18th century tried the cantons of Berne and Solothurn, to secure endangered by erosion banks in numerous places. With the first Jura water correction, one of the largest river construction projects in Switzerland in the 19th century, renovated Confederation and the cantons the marshy, and at risk of frequent flooding Berner Seeland by the Aare River and its sediment were diverted into Lake Biel. Since 1939, the Regulierwehr port controls the water balance of the lakes and the river Aare in the section at the foot of the Jura. The second Jura water correction improved by 1960, the effect of water level regulation.

Hydropower

Starting with the reservoirs Oberaarsee and Grimselsee in the headwaters of the river Aare is the electricity production in numerous hydropower plants.

Nuclear power plants

On the river there are the Swiss nuclear power plants Muhlenberg, Gösgen and Beznau, use their cooling systems water from the River Aare.

Flood

The mean annual flood of the River Aare is at the measuring point Untersiggenthal, Stilli 1574 m³ / s, making it contributes 23:59 % of the total MHQ of the Rhine ( 6670 m³ / s). The highest ever recorded annual peak was at the flood of the century in 2007 and was 2656 m³ / s

The table of flood probability: