a river in Western Europe. The Rhine has a length of 1,320 km (from the sources of the Vorderrhein) and drains an area of 224,400 sq km (not including the basin of the Meuse River). The Rhine flows into the North Sea. The Rhine Valley is situated within the borders of Switzerland, Lichtenstein, Austria, the Federal Republic of Germany (FRG), France, and the Netherlands.
The Rhine rises in two headstreams in the Alps. The principal source—the Vorderrhein—joins the other source—the Hinterrhein—at the city of Reichenau. In this mountainous section the river breaks through the spurs of the Alps, the Jura, and the Schwarzwald, forming rapids and waterfalls (including the Rheinfall), and flows through Lake Constance. The largest left tributary, the Aare River, empties into the Rhine; after the merging of the two rivers, the width of the Rhine reaches 200 to 300 m. Below Basel the river changes its direction abruptly from east-west to north-south, and for a distance of more than 300 km it flows northward through the Upper Rhine Lowland, forming a terraced plain that attains a width of 10–12 km. In places the riverbed has been straightened and embanked to protect the valley from flooding; its width ranges from 200 to 500 m. In this section the major right tributaries, the Neckar and the Main, enter the Rhine. The central course of the Rhine—from the city of Bingen to the mouth of the Sieg River—traverses a narrow silt valley, which in places has the appearance of a gorge, and cuts through the Rhenish Slate Mountains. The width of the Rhine near the Lorelei is 115 m.
At Koblenz the Rhine is joined by the Mosel, an important left tributary. The lower course, which is situated within the central European Plain, has been straightened and embanked. The Rhine’s width ranges from 400 to 550 m, and in this section the river is joined by a right tributary, the Ruhr.
In the Netherlands the Rhine, along with the Maas (Meuse) and Scheldt rivers, forms a complex delta. Branches of the Rhine, principally the Waal and Lek rivers, are generally situated at a level higher than the adjacent lowland plain; for this reason they are embanked and protected by high dikes.
The upper course of the Rhine is characterized by spring and summer high waters and by a small wintertime flow. Along the middle and lower sections, where the Rhine is joined by tributaries that are full of water during the winter and spring, the water regime becomes more complex, and the river has a great deal of water throughout the entire year. Such a regime is favorable for navigation. The Rhine’s branches are affected by the ocean tides, which occur twice every 24 hours and which cause the river level to rise 1.5 to 2 m.
The average discharge is 420 cu m per sec at a point above the mouth of the Aare River, 1,030 cu m per sec at Basel, and approximately 2,500 cu m per sec at the point above which the Rhine divides into branches. The average annual flow is about 79 cu km. The maximum flow rate at the river’s mouth exceeds 11,000 cu m per sec. The Rhine freezes over only during very cold winters for a period of up to one month.
The Rhine is Western Europe’s most important international waterway. Regular navigation is maintained as far as Basel (886 km from the river’s mouth) and through Lake Constance. The river is navigable by small vessels above the city of Laufenburg. The Rhine is linked by canal with the Danube, Rhône, Marne, Weser, Elbe, and Ems rivers. Navigable tributaries include the Neckar, Main, Lahn, Mosel, and Ruhr. The total length of the waterways in the Rhine Basin is approximately 3,000 km. The average annual freight turnover, based on the turnover at the city of Emmerich (near the border of the FRG and the Netherlands), is about 100 million tons (in 1972, 102 million tons). Every day between 650 and 700 vessels travel on the river. The Rhine’s principal ports are Rotterdam (with its outer port of Hoek van Holland) in the Netherlands; Duisburg, Cologne, Mainz, Ludwigshafen, and Mannheim in the FRG; Strasbourg in France, and Basel in Switzerland. Bonn, the capital of the FRG, is located on the Rhine.
The hydroelectric power resources of the Rhine and its tributaries are utilized by the FRG, Switzerland, and France. By 1970 some 1.3 gigawatts had been harnessed in the Rhine Basin by the FRG (with total hydroelectric power resources estimated at 1.8 gigawatts). A cascade chain of 11 hydroelectric power plants has been built on the Rhine above Basel; prior to 1970 eight hydroelectric power plants were built on the Rhine-Rhône Canal between Basel and Strasbourg, including one at Kembs (1932) and one at Strasbourg (1970).
The Rhine is badly polluted almost throughout its entire length. The discharge of toxic wastes and waters heated by steam and atomic power plants has led to a decrease in the amount of soluble oxygen, which is necessary for the growth of many aquatic organisms. As a result, nearly all fish life has been exterminated. Engineering works have been carried out as part of the Delta Plan in the estuary region of the Rhine, Maas, and Scheldt rivers. Basically for protection against flooding, the project has included the construction of dikes and locks. The Delta Plan, however, has inflicted serious damage on the fish life and the numerous colonies of waterfowl at the mouth of the Rhine.
A. P. MURANOV