IJssel

HistoryEdit

The name IJssel (older Isla, Isala, from *Īsalō), is thought to derive from a Proto-Indo-European root *eis- "to move quickly" (cf. Old Norse eisa "to race forward", Latin ira "anger"). In the Middle Ages, the Zuiderzee had not yet formed, and in its place there was an inland lake known as Vlies (Lat. Flevo), and the IJssel flowed through the surrounding lakelands. However, since the formation of the Zuiderzee and obstruction from the Afsluitdijk, the IJssel no longer flows into its estuary, the Vlie, now restricted in meaning and referring only to the strait separating the islands of Vlieland (itself named after the Vlie strait) and Terschelling. It is hypothesised that the now-poldered tidal inlets near Medemblik and the IJ (near Amsterdam) once were branches of river IJssel.

The river was a natural line of defence and in April 1945 had to be stormed by assault troops of the Allied armies liberating the Netherlands from the occupying forces of Nazi Germany. Canadian histories refer to the river in English as "Ijssel".

The IJssel as the lower part of the Oude IJsselEdit

The IJssel was the lower part of the small river Oude IJssel (lit. "Old IJssel", German Issel), that rises in Germany and is now a 70 km long tributary of the IJssel. The connection between Rhine and IJssel was probably artificial, allegedly dug by men under the Roman general Nero Claudius Drusus as a defence against Germanic tribes and to let Roman ships carry troops along it. The current Oude IJssel is the second-largest contributor to the flow of the river until today, after river Rhine.

The source of the Oude IJssel is near Borken in North Rhine-Westphalia, Germany. First it flows south-west until it nearly reaches the Rhine near Wesel; then it turns north-west. After passing through Isselburg it crosses the border with the Netherlands. The river, called Oude IJssel from here, then flows through Doetinchem and joins the IJssel at Doesburg.

CharacteristicsEdit

The average discharge of the IJssel can change significantly. The average discharge has been stated as 300 cubic meters per second. This can be as low as 140 and as high as 1800, depending on the Nederrijn locks west of Arnhem, which regulate the amount of water taken in by the Nederrijn and IJssel branches.

As a lowlands river, the IJssel has a lot of bends and naturally occurring dead branches (locally called "hank"); some bends have been cut off by man (most notably near Rheden and Doesburg), reducing the river's length from 146  km to 125 km, but not nearly as radically as with river Meuse. The naturally occurring phenomenon of sedimental island-forming in the outside of bends has been regulated to the point of non-occurrence since the late nineteenth century.

The IJssel as a Rhine distributaryEdit

From the moment the connection between the Rhine and IJssel was dug, the Rhine became the largest contributor to the flow of the IJssel, although only a relatively small amount of the total Rhine flow makes its way into the IJssel system. Various tributaries can sometimes add a considerable volume of water to the total flow of the IJssel, such as the Berkel and Schipbeek streams. The IJssel river is the only branch of the Rhine delta that takes up tributary rivers rather than giving rise to distributaries.

Only in the last few miles of the river's run, near the city of Kampen, distributaries form, resulting in the relatively minor IJssel delta. Some of the branches have been dammed up to lower the risk of flooding; others have silted up. Several of the delta branches are, however, still connected without interruption. Most of the damming-up was done prior to 1932, when the Zuiderzee was turned into the freshwater IJsselmeer lake. The area had been prone to flooding in times of northwestern gales, pushing back the saline Zuiderzee water into the IJssel delta and preventing the water flowing from the mouths of the IJssel branches from discharging into the Zuiderzee.

The modern-day names of the delta branches are, west to east, Keteldiep, Kattendiep, Noorddiep, Ganzendiep and Goot. Of these, the Keteldiep and Kattendiep channels are the main navigational arteries; the Noorddiep has been closed off at both sides. Another branch, De Garste, had already completely silted up by the middle of the nineteenth century. Until the beginning of the twentieth century, the Ganzendiep branch up to the Goot fork was known as IJssel proper. due to it being the historical main channel, with the present-day main channel being called Regtediep or Rechterdiep until well into the twentieth century

The IJssel, although now technically "merely" a Rhine branch, has retained most of the character of a distinct river in its own right, in no small part due to the fact that it has its own tributaries and, in river Oude IJssel, even a former headstream.

Tributaries and connecting canalsEdit

The following canals and tributary streams connect to the IJssel, in downstream order:

Road bridgesEdit

Road bridges across river IJssel (with nearest places on the left and right bank):

Railroad bridgesEdit

Railroad bridges (with nearest train station on the left and right bank):

Cable ferriesEdit

Only those ferries capable of carrying motorised vehicles are included.