Orbe level
The Orbe plain (also Orbe plain ; French: Plaine de l'Orbe ) is an almost 50 km² large alluvial plain in the Swiss canton of Vaud , through which the Orbe and the Thielle (German: Zihl ) flow. Thanks to the mild and relatively dry climate in the lee of the Upper Jura, it is one of the most important agricultural and vegetable growing areas in Switzerland.
geography
The plain is on average 2 to 3 km wide, 16 km long and is 435 m above sea level. M. Its northern part extends in a northeast-southwest direction. In the area of the town of Orbe it describes an arc so that the southern part runs in a north-south direction. The Orbe plain is bounded in the northwest and west by the Jura foot plateau, a plateau that rises slowly towards the foremost Jura chain and is cut by several river valleys, and in the south by the Mormont bar , over which the watershed between the catchment areas of the Rhine and Rhone runs and which separates the plain from the adjoining valley of the Venoge to the south . The elongated molasse ridges of the northern Gros de Vaud border the Orbe plain to the east, and Lake Neuchâtel forms the border in the northeast . In the northern part of the plain rises the isolated Mont de Chamblon (552 m above sea level), a broad ridge near Yverdon-les-Bains .
geology
The formation of the Orbe plain is due to several faults , which were responsible for the vertical and horizontal displacement of the rocks. The sequence of layers in the subsurface of the plain consists of up to 200 m thick deposits from the Cretaceous period , some of which protrude to the surface of the earth in the area of the fault lines outside the actual plain and show an alternation of limestone and marl layers. Above it lies a layer of the Lower Freshwater Molasse , which is also around 200 m thick on average and which was eroded from the Alpine rock cover by rivers around 30 to 22 million years ago and transported here.
In the course of the Pleistocene , debris from the Rhone Glacier was deposited in the Orbe plain during the Ice Ages . The sediments that exist today are predominantly ground moraines from the Worm Ice Age Rhone Glacier. The rock material from the earlier ice ages, however, was largely eroded again during the subsequent interglacials . In the Holocene, a layer of lacustric sediments from Lake Solothurn (temporarily a post-glacial Jura rim lake that stretched from Solothurn to the Mormont) was deposited over these Pleistocene deposits . After the water had gradually withdrawn, a wide swampy lowland remained.
Water network
The main river of the Orbe plain is the Orbe, which, however, only reaches the plain at the medieval town of the same name. Here it emerges from a ravine in the Jura foot plateau into the plain. The orbe unites in the plane with the talent ; from this confluence to the confluence with Lake Neuchâtel, the water is called Thielle . The southern section of the Orbe plain is drained by the Nozon , which formerly flowed into Talent at Chavornay . These three rivers, together with a few short side streams that flow down from the surrounding heights, form the water network of the Orbe plain. They used to meander through the marshland in numerous meanders .
history
In the peripheral areas of the Orbe plain there have been some Celtic settlements since the Iron Age (from around 800 BC) . In Roman times there was the Vicus Eburodunum near Yverdon-les-Bains . There was also an urban settlement near Orbe and a little north of it a Roman manor, which is considered the largest building complex of this type in Switzerland. A Roman road ran through the Orbe plain and connected the area with the Lake Geneva basin.
From the 9th century in the Burgundian period, the first settlements developed on slightly elevated locations on the edge of the plain, from which today's village structure developed. Since the plain itself was swampy and flooded over and over again, it was considered uninhabitable for a long time. Only the city of Yverdon is on the plain.
Smaller drainage and dumping measures have been carried out in the vicinity of the settlements since the 16th century . At the time of the Thirty Years' War the project was pushed to connect the Rhône and the Rhine with a waterway through the Orbe plain. From 1638 to 1648 the Entreroches Canal was built between Yverdon and Cossonay , which was to establish the connection to the Venoge . However, financing difficulties prevented the full expansion of this waterway.
Larger improvements were only carried out from 1870 in connection with the first correction of the Jura waters . All rivers in the Orbe plain have been canalized and straightened. The Thielle received side canals between Orbe and Yverdon, namely the Canal Occidental on the left and the Canal Oriental on the right, for which parts of the former Canal d'Entreroches were used. Both canals run through Yverdon and have separate mouths into Lake Neuchâtel.
use
![](https://upload.wikimedia.org/wikipedia/commons/thumb/a/ac/Torffelder_der_oberen_Orbe-Ebene_bei_Bavois_%281918%29_-_edit.jpg/440px-Torffelder_der_oberen_Orbe-Ebene_bei_Bavois_%281918%29_-_edit.jpg)
During and after the First World War, which put SA de Laminoirs et Cablerie Cossonay for peat extraction two extensive Decauville - peat railways with gauges 500 and 600 mm in the Marais of Puits in Bavois in the Orbe plain one. Their peat presses were immovable in a suitable location, and the wet peat was transported from the mobile cutting machines via innovative endless wire rope sod conveyors to fixed conveyors and from there to the peat presses with tilting lorries on Decauville tracks .
With the amelioration, a large area of valuable cultivated land was gained. Today the Orbe plain is used intensively for agriculture. It is one of the most important vegetable growing areas in Switzerland; there is also tobacco and grain cultivation. There are only very few remains of the former moorland, for example the Marais des Puits near Bavois and the Creux de Terre near Chavornay, a nature reserve that was only created with the renaturation of earlier clay pits. At Orbe and Chavornay, the plain is increasingly being used by commercial and industrial zones. In 1925 , the Vaudois penitentiary in Bochuz (Pénitencier de Bochuz) was built near Orbe .
Important traffic axes run through the Orbe plain, namely the Yverdon-Lausanne railway line since 1855 and the A1 motorway , which connects these two cities, since 1981 .