Congestion root

The waterway root is the point in a flowing water up to which an artificial change in the river occurs through damming . Above the reservoir root, natural conditions prevail; below the reservoir root, the water level above the river bed is increased and the flow velocity is reduced.

In principle, between a storage root to the main inflow of a dam and a reservoir head in a jammed flow ( barrage , damming) to distinguish.

Reservoir root of a dam

The actual location of the reservoir root varies with the height of the water level in the dam. Since there is only an extremely low flow speed within the reservoir and therefore there is no water level gradient, the dam root can be seen clearly and with the naked eye: this is where the stream meets the reservoir.

A so-called pre- dam is often located at the dam root in front of the actual reservoir . Pre-dams usually have a constant water level, so that in this case the reservoir root is fairly well defined.

Reservoir roots at reservoirs in rivers

The root of the reservoir is difficult to see on large rivers, as there is clear flow and water level gradient within the reservoir. It can therefore only be proven mathematically or defined by observations with and without the influence of traffic jams. Depending on the flow rate and the control of the weir, the position of the weir can vary considerably.

Many rivers (e.g. the Moselle ) are dammed several times one behind the other to make them navigable or to avoid uncontrolled flooding. In such a case, there is often no longer an unaffected stretch of river and therefore no barrage root.

Traffic engineering

In a figurative sense, the term is used in traffic engineering and describes the place where a traffic jam occurs (especially in Switzerland and Austria). Often it is the same place in front of constrictions such as tunnels, construction sites or accidents. The traffic jam then moves against the direction of travel. The end of the traffic jam moves with a progression speed that is proportional to the number of incoming vehicles.

The beginning of the congestion can also move against the direction of travel at a speed that is proportional to the outflowing vehicles, which it typically does when the accident sites are cleared. After a while, the traffic jam is in a place where its existence - from a purely local point of view - no longer seems explainable.