Slope and fall are one of the most important characteristics in a comprehensive study of a natural watercourse. Without taking into account these two indicators, it is impossible to design a dam or lay a water transport route for a bulky cargo ship. In this article we will try to calculate the fall and slope for the Volga River.
Volga: what do we know about the great Russian river?
The largest watercourse in Europe carries its vast waters into the Caspian Sea. Volga is the largest river system in Europe. Within its catchment basin four Germany could easily accommodate! The total length of the river is 3,530 kilometers.
Conventionally, hydrologists divide the riverbed into three large sections: the Upper, Middle and Lower Volga. On its long journey, it receives about two hundred other large tributaries. After merging with the Oka and Kama, the Volga turns into a powerful, full-flowing river, the width of which in some places reaches several tens of kilometers!
Volga is one of the most developed rivers in Russia. Four millionaire cities are located on it: Volgograd, Samara, Kazan and Nizhny Novgorod. During the twentieth century, eight large hydroelectric power plants were built in its mainstream. The river itself in the middle and lower reaches has turned into a cascade of large reservoirs. In addition, the Volga is connected to four seas (Baltic, Black, Azov and White) by a system of artificial canals.
The slope of the river and the formula for its definition
Any river has its source and mouth. The difference in height (in meters) between these two points is called the fall of the river. The magnitude of the fall can be completely different, even for two neighboring and equal in length streams.
The slope of the river is called the ratio of the magnitude of the fall to its total length. As a rule, the slope of the watercourse is expressed in meters per kilometer (sometimes in ppm) and is indicated by the Latin letter I. It depends primarily on the terrain. So, the slopes of mountain rivers are ten times higher than the similar indicators for flat watercourses.
The formula for determining the slope of a river is extremely simple. It has the following form:
I = H / L, where:
H is the fall of the river (in meters);
L is the total length of the watercourse (in kilometers);
I is the slope (in m / km).
The slope and fall of the Volga River: calculations
Now let's determine the value of the slope for the Volga River. This is not at all difficult to do. The calculations include four sequential actions:
- Search for points of the source and mouth of the Volga on the map, determining their absolute heights.
- Calculation of the fall of the river (in meters).
- Measurement of the total length of the watercourse (in kilometers).
- Determination of the slope of the river by the formula.
The Volga flows from several springs on the Valdai Upland, within the Ostashkovsky District of the Tver Region. The absolute height of this place is 228 meters above sea level.
The Volga Delta (by the way, the largest in Europe) consists of 500 sleeves. The mouth of the river is below sea level (at a mark of –28 meters). Thus, the fall of the Volga River is 256 meters. According to hydrographic data, the total length of the Volga is 3530 km. And now we can calculate its bias. To do this, divide the fall by the length: 256 meters / 3530 km = 0.0725.
Thus, the average slope of the Volga is 0.0725 m / km.