# The fall and slope of the river - what is it? Define the slopes of the rivers: the Volga, Amur, Pechory

The river is a water flow of naturalorigin, which flows along the channel, which they also worked out. You can measure the length of this watercourse, the number of its tributaries, the area of the general catchment, etc. One of the main hydrological indicators is the slope of the river. How correctly to calculate it?

## What is the fall of the river?

Any natural watercourse on our planet flowstop down. The reason for this is the Universal Gravity Law, known to all of us, which was discovered by Isaac Newton in the middle of the 17th century. All rivers, as a rule, start from underground springs or flow from large lakes. Then they carry their water down (smoothly or swiftly) to the seas and oceans.

The fall of the river shows us how much it loses inthis or that watercourse during its "journey" along the earth's surface. In other words, this is the difference in height between the source point and the point of the river mouth. The fall can be complete or partial (when you need to calculate this figure for a certain length of the channel).

Calculate the fall of the river is elementary. For this you need to know the height of its source and mouth. For example, we are given a river A with a total length of 2000 km, which begins its journey at 250 m, and flows into the lake at a height of 50 m. The difference between these two marks will be 200 meters. This will be the fall of the river A.

Knowing the fall, you can calculate the slope of the river. How to do it correctly - read in the next section.

## How to calculate the gradient of the watercourse?

The slope of the river is the ratio of the value of the fall of the watercourse to its total length. This indicator can be expressed in percent, ppm (most often), degrees or in m / km.

The slopes of the plains and mountain rivers vary considerably. In the first case, this indicator rarely exceeds 0.1 m / km. The slopes of mountain rivers can be tens or even hundreds of times larger.

Calculate this figure is also easy. Let's return to our river A, the fall of which is 200 meters. To calculate the slope, you need to divide this value by the value of the river length: 200 m / 2000 km = 0.1 m / km. Proceeding from this, we can say that our river A is flat and has an insignificant speed of its current.

The fall and slope of the river can be depicted graphically. To do this, use the so-called longitudinal profiles. Axis "x" of this graph will be the length of the river, and the "y" axis - the height of the terrain. This profile looks like this:

## Fall and slope of the Volga

To solve similar tasks are taught in school, in lessons on geography in the 8th grade. Take as an example the largest watercourse in Europe - the Volga. Let's try to calculate the fall and slope of the river.

The Volga flows in the European part of Russia, inlimits of 15 subjects of the federation. She repeatedly changes her direction. This is the most important water artery of the country, the largest river in the world from among those watercourses that do not flow into the sea or the ocean.

The Volga originates from the Valdaielevations, at an altitude of 228 meters above sea level. Within the Astrakhan region, it flows into the Caspian Sea. At the same time, the mouth is located at a height of -28 meters. Thus, the total fall of the Volga is 256 meters. Now calculate the slope of the river.

The Volga has a total length of 3530 km. At the same time, it collects its water from a huge area of 1.36 million square meters. km. This is four times more than the area of Germany! To calculate the slope of the Volga, the following mathematical action should be performed: 256 meters / 3530 km = 0.07 m / km.

## The fall and slope of the Amur River

One of the main rivers of the Far East, flowingbetween two states (Russia and China) is the Amur. Its source is considered to be the site of the merger of Shilka and Argun. The height of this point above the sea level is 304 meters. Further, the Amur flows mainly to the east and flows into the Sea of Okhotsk. The height of its mouth is 0 meters. Thus, the total fall of the Amur is 304 meters. Calculate the slope of the river.

Amur has a total length of 2824 km. The area of the river basin is 1.85 million square meters. km. To calculate the slope of Cupid, you must perform a simple mathematical action: 304 meters / 2824 km = 0.11 m / km.

This indicator tells us that on the sitea river a mile long, the Amur River "loses" 11 centimeters in height. It is important to note that the general bias of one or another watercourse is not very informative. After all, the geomorphological conditions (relief conditions) in which the river bed is located can vary considerably. Therefore, it is better to calculate this indicator for individual short sections of the river bed.

## Fall and slope of the Pechora River

Pechora is a fairly large Russian river,flowing within the Komi Republic and the Nenets Autonomous District. It originates in the mountains of the Northern Urals, at an altitude of 630 meters above sea level. Pechora flows into the same name of the Barents Sea lip, forming a vast delta. The height of the mouth is 0 meters. Calculate the fall and slope of the river.

Pechora has a total length of 1809 km. The fall of the river is 630 meters. The area of the river basin of Pechora in comparison with the Volga and the Amur is not large - only 330 thousand square meters. km. To calculate the slope of the Pechora River, the following mathematical action should be performed: 630 meters / 1809 km = 0.35 m / km.

As we see, among the three examined in thisThe greatest deviation is characteristic of rivers in the Pechora River. In general, the definition of this indicator helps hydrologists to study the valley of a particular river, its water regime and channel processes.