Which river flows through the country the most?

The Danube River is the second longest river in Europe after the Volga River. It is praised as the "Blue Danube River", winding like a blue ribbon across the land of Europe. It originates from the eastern slope of the Black Forest Mountains in southwest Germany, flows from west to east through Austria, the Czech Republic, Slovakia, Hungary, Yugoslavia, Bulgaria, and Romania, and empties into the Black Sea near Lina in Romania. It flows through 9 countries and is the river with the largest number of trunk streams in the world. It has a total length of 2,980 kilometers and a drainage area of ??817,000 square kilometers. There are more than 300 tributaries. The left bank tributaries include the Fager River, the Tisza River, the Oort River, the Prut River, etc.; the right bank tributaries include the Inn River, Drava River, Sava River, Morava River, and Iraq. Sk River et al. The basin area is 817,000 square kilometers. There are vast plains in the middle and lower reaches. The average annual flow of the estuary is 6,430 meters per second, and the amount of seawater discharged into the river is 203 cubic kilometers. The water power reserve reaches 35 million kilowatts. It is an important international waterway in Central and Southeast Europe.

The Danube River is praised as the "Blue Danube River" because of its turquoise water color. It is the second largest river in Europe after the Volga River. It originates from the eastern slope of the Black Forest Mountains in southwest Germany, flows from west to east through Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Romania, and Ukraine, and empties into the Black Sea in central and southern Ukraine. It flows through 9 countries and is the river with the largest number of trunk streams in the world. The tributaries extend to seven countries including Switzerland, Poland, Italy, Bosnia and Herzegovina, the Czech Republic, Slovenia, and Moldova, and finally flow into the Black Sea at Sulina in eastern Romania. The Danube River has a total length of 2,850 kilometers, a drainage area of ??817,000 square kilometers, an average annual flow of 6,430 cubic meters per second at the estuary, and a multi-year average runoff of 203 billion cubic meters.

The main stream of the Danube River is about 965.6 kilometers long from its source to the Hungarian Gate near Bratislava. From Ulm to the Hungarian Gate, the length is 708 kilometers, with a drop of 334 meters; from the Hungarian Gate to the Tiemen Gorge is the middle reaches, about 954 kilometers long, with a drop of 94 meters; below the Tiemen Gorge is the lower reaches, about 930 kilometers long, with a drop of 38 meters. rice.

The Danube River once played a very important role in the process of immigration and political reform in Central and Southern Europe. The castles and fortresses that lined its banks formed the boundaries between great empires; while its waterways served as commercial thoroughfares between nations. In the 20th century, it continued to function as a trade artery. The Danube, especially along its upper reaches, has been harnessed to produce hydropower. Some cities along the Danube River, including some capitals, such as Vienna, Bratislava, Budapest and Belgrade, rely on it to develop their economies.

Basin Landform

The Danube River is surrounded by mountains on three sides and is located in the southeast of Central Europe. There are the Black Forest Mountains in the west, the Alps, Velebit Mountains, Dinara Mountains, Laoshan Mountains and the Balkan Mountains in the south from west to east; the Czech Forest Mountains, Sumava Mountains, Sudeten Mountains and Carpathians are in the north from west to east. Qianshan. Facing the east is the black teaching.

The Bregg River and the Brigach River are the two source rivers of the Danube River. Their origins are on the eastern slopes of the Black Forest Mountains in Germany, with altitudes of 1010 meters and 1125 meters respectively. After passing through Donaueschengen, the confluence point of the two rivers, the Danube flows northeast. From Ulm to Passau, the Danube River buds across the northern side of the Bavarian Plateau, and in the section from Ingolstadt to Regensburg, the Danube River crosses the Swabian Frank Mountains with a narrow and deep valley. After passing Regensburg, the river turns to flow southeast, from Passau to Linz, a popular destination, and passes through the hilly areas between the northern slopes of the Alps and the Czech plateau, forming a typical mountain river with narrow valleys and rapid flows on many beaches. After passing Linz, the river course changes to the east and enters the Vienna Basin. After the Danube River flows out of the Hungarian Gate Gorge near Bratislava, Slovakia, it enters the Little Hungary Plain. The river bed widens, the flow slows down, and the river channel separates and bypasses the mud. The large and small Xuter Islands (area 1901 square kilometers) formed by sand siltation. After exiting Comano, the Danube enters the Visegrad Gorge, then turns south, passing through Budapest and entering the Great Hungarian Plain. The river has the characteristics of a plain river, with the valley widening, the riverbed smaller than the drop, and the river channel curved, often with branches and oxbows. lake. The Danube River turns eastward from Belgrade, Yugoslavia, and flows straight into the Southern Carpathians. After years of cutting, the magnificent and steep Catlacta Canyon was formed. The canyon is 130 kilometers long and consists of four canyons. The most famous of them is Tiemen Gorge. The water level difference between the beginning and the end of the canyon is 30 meters, the narrowest point is only 132 meters, and the deepest reaches 82 meters. After the Danube River leaves the Iron Gate, it enters the lower reaches of the plain. The river valley is wide, and there are lakes and swamps about 10 kilometers to 15 kilometers wide on the shore. The estuary delta is 80 kilometers long and extends toward the Black Sea at an annual growth rate of about 24.38 meters to 30.5 meters. The delta covers an area of ??more than 5,640 square kilometers. At the apex of the delta, the Danube River divides into three branch rivers, namely Kiliya, Sulina and Sventu George, whose flows into the sea account for 66%, 16% and 18% of the total volume respectively.

The Danube River Basin covers an area of ??approximately 817,000 square kilometers, and contains various natural conditions that affect its water sources and water regimes. These natural conditions help to form a river network with many forks, dense water, and deep water. There are about 300 tributaries, more than 30 of which are conducive to navigation.

More than half of the entire Danube Basin is drained by its right bank tributaries; the flow and drainage of these tributaries account for 2/3 of the entire Danube River, collecting water from the Alps and other mountainous areas.

Basin Climate

In the western and southeastern parts of the Danube River Basin, the temperature and humidity are suitable and the rainfall is abundant. The entire Danube River Basin belongs to the temperate climate zone, transitioning from a temperate maritime climate to a temperate continental climate. The estuary area has grassland climate characteristics. Affected by the continental climate, the entire winter is cold. Taking Bucharest as an example, there are 3 months in summer where the temperature is below 20°C and the highest temperature can reach 34°C. In winter, there are 3 months when the temperature is below 0°C and the lowest temperature is -3.5°C.

As for the entire basin, most precipitation occurs in summer and early autumn (June to September), and snow falls in winter in high mountain areas. Snowfall accounts for 10% to 30% of the annual precipitation. Rainfall is unevenly distributed in the basin. The Austrian Alps have the highest rainfall, with an average annual rainfall of more than 2510 mm, and a maximum annual rainfall of more than 3000 mm. The areas with the lowest rainfall are the Greater Hungarian Low Plains and the lower parts of the Morava River Basin in Slovakia, as well as the downstream areas, especially Tin The average annual rainfall in the areas east of the Leite River and the mouth of the river is less than 600 mm to 400 mm, and the rainfall in dry years is less than half of the average rainfall. Generally speaking, the annual rainfall in the upper reaches is relatively large, about 1000 mm to 1500 mm, while the middle and lower reaches plain areas have less rainfall, about 700 mm to 1000 mm, with an average of 863 mm in the basin.

Danube River basin scope and water flow

Heavy rain or long-term continuous rainfall in summer and autumn, melting of mountain snow in spring and ice in winter are the main sources of floods in the Danube River. Danube floods have two basic characteristics. First, it is extremely rare for major floods to occur in the entire basin, and most floods are limited to local river sections. Second, floods may occur in all seasons throughout the year, but they only occur in different rivers. part.