Watershed is a concept that is actively studied by the science of hydrology. What is the essence and significance of this concept for science? What types of watersheds are distinguished by scientists? The answers to these questions are in our article.
Watershed is… Definition of concept
There are tens of thousands of rivers on our planet. And each of them collects water from a certain area. A watershed is a conditional line drawn on the earth's surface. Before defining the essence of this concept, you should familiarize yourself with some other terms. We are talking about two hydrological concepts: a river system and a river basin.
A river system is a water system consisting of a main river and all its tributaries. A river basin refers to the area from which all water (both surface and underground) flows into a particular river system. Now you can give a logical and understandable definition of the concept of a river watershed.
A watershed is a line that separates neighboring river basins. In mountainous or hilly areas, it is more pronounced, and in flat areas it is weaker. In the mountains, the watershed linesoften pass along ridges and ridges. At the same time, the runoff of water and precipitation is directed in different directions from the ridge (on opposite slopes).
Within the lowlands, the watershed may not be clearly expressed in relief. Moreover, in such areas, its line may even shift in one direction or another over time or depending on the season.
Main types of watersheds
The watershed separating basins of different oceans or denoting areas of inland runoff is called continental. For example, in America, this line runs along the highest ridges and peaks of the Cordillera and the Andes mountains.
In Europe, the most important watersheds are the Alps, the Scandinavian mountains, and the Valdai Upland. Three major rivers originate within the latter landform: the Volga, the Dnieper, and the Zapadnaya Dvina. Moreover, each of them carries its waters to different seas - to the Caspian, Black and B altic, respectively.
In addition, it is customary to distinguish between underground and surface watersheds. The first of them delimits underground drainage basins, and the second - surface ones. And they don't always match.
Sometimes the concept of a watershed is used to distinguish between individual major landforms of the Earth. For example, Orinoco is a river that is a watershed between the Guiana Plateau and the Andes in South America. However, such a formulation is not entirely correct from the point of view of hydrological science.
Watershed studies
The study of the conditional topographic lines described above is of great scientific and practical importance. Especially when it comes to the active exploration of geographic space by man.
Thus, when designing bridges, dams or power plants on a river, it is simply necessary to have an idea of how the watershed lines run in a particular region. Even more important is the detailed study of watersheds when planning large reservoirs. This is necessary in order to accurately calculate the volume of possible filling of the future reservoir.
The Volga river basin and its watershed
Volga is the largest river system in Europe, which includes over 150 thousand watercourses: rivers, permanent and intermittent streams. The drainage basin of this river occupies a huge area - 1.36 million square meters. km. This territory is comparable in size to states such as Peru or Mongolia. Within the Volga river basin there are 30 subjects of the Russian Federation, one region of Kazakhstan and dozens of large cities (in particular, Moscow, Ryazan, Tver, Orel, Kazan, Astrakhan, Perm and others).
The Volga watershed passes through the Central Russian Upland in the west, the hills of the Northern Uvals in the north, along the western slopes of the Ural Mountains, the Common Syrt Upland and the Caspian Lowland in the south.
