River feeding - flow of water into rivers.

There are four sources of river nutrition (table).

Rivers depend on the flow of water water content, seasonal flow distribution, water regime. Rivers often have a mixed supply.

At the same time, the source that provides most of the river flow is considered to be predominant. It is he who determines the regime of the river.

River mode - intra-annual distribution of runoff, characterizing the life of the river.

Russia is dominated by rivers snow food. They have clearly expressed seasonal fluctuations in the level and water content of the river.

A friendly spring contributes to the rapid melting of snow, the rise of water in the river and the flooding of the floodplain - high water. In summer, during the dry period, there is a summer low water.

Summer low water — stable low level and water consumption.

In winter, rivers freeze and groundwater becomes the main source of food. As a result, the runoff is reduced and winter low water.

Most of the lowland rivers of the East European Plain, the West Siberian Lowland, and the Central Siberian Plateau belong to the type of rivers of predominantly snow-fed with spring floods.

On rivers dominated by rain supply develops flood regime.

Floodcom called a sharp short-term rise in water in the river, which occurs most often due to heavy rains.

If floods are typical for spring, then floods can occur at any time of the year. So, on the Black Sea coast, in the northern foothills of the Caucasus, short-term high floods occur as a result of heavy rains, both in summer and in winter.

Rice. 137. Mountain river
Rice. 138. Plain river

The regime of rivers in some areas (for example, in Russia - Primorye and Amur) is formed under the influence monsoon climate. Heavy rains cause high and prolonged floods in late summer and early autumn. Little snow falls, so there is no high spring flood, a low winter low water is typical.

High floods often take on the character of catastrophic floods. Significant areas of land are flooded, great damage is caused to the population, the economy, and the natural environment.

Melting glaciers ( glacial nutrition ) causes summer floods on mountain rivers (for example, in Russia - the Baikal, Transbaikalia, Altai).

ground food most rivers does not play a decisive role, but serves as an important addition to the main - snow, rain, glacial.

With the onset of autumn, the rivers begin to freeze and become covered with ice. The duration of freeze-up on the rivers generally decreases from north to south and southwest from about 8 to 2-3 months. material from the site

In the spring, as the temperature rises and the snow melts, the ice begins to move. It flows especially rapidly on rivers flowing from south to north (in Russia, for example, the Northern Dvina, Lena), since here snow melting begins in the upper reaches, and ice in the lower reaches of the river holds back the pressure of spring waters. As soon as it breaks open, a powerful flood wave begins.

Rice. 140. Ice drift

We all know perfectly well that several largest rivers of our planet, the width of which reaches 50-60 kilometers.


But the source of even the largest river is a thin, inconspicuous stream. Only after running many hundreds of kilometers, having been saturated with the moisture of many large and small tributaries, the river becomes truly powerful and wide. Do you know what river nutrition is, and what are its sources? Yes, the river also feeds, but, of course, not cutlets with mashed potatoes and water from their tributaries.

Nutrition and river regime

How to measure a river? You can measure its length, the width of the channel and the depth of the bottom. Another important characteristic is the water consumption, i.e. the amount of water that flows through a channel per unit of time. If you make these measurements throughout the year, you will find that the level and flow of water in different periods are not the same.

Continuing observations for several years in a row, you can see that in spring and autumn the river becomes more full-flowing, and in summer and winter the amount of water in it decreases. Scientists call these seasonal fluctuations the regime of the river.

It is customary to distinguish three main periods in the regime of any river:

- - a long period when the amount of water reaches a maximum, as a rule, due to the spring melting of snow;

- - periods of lowering the water level, usually occur in summer and winter;

- - short-term and sharp, lasting only a few days, rise in water level due to heavy rains or sudden snowmelt.

It is easy to see that fluctuations in the water level in the river are caused by an increase or decrease in its supply, i.e. water entering the river from tributaries, streams and underground sources. Hydrologists (specialists who study the "behavior" of natural waters and reservoirs) identify four main sources of river nutrition - snow, ice, rain and underground. One of them is usually predominant, but the river does not refuse the rest either.

Rain, snow supply

Rivers fed exclusively by rain are characterized by frequent and sudden floods. As a rule, these are tropical and subtropical rivers flowing from peaks or hills.


In our country, there are also rivers with a predominantly rain source of food. They flow from the peaks of Altai, the Caucasus, the Baikal region and other similar regions. But for our rivers, no less powerful source than rain is snow, or rather, its spring melting. "Snowy" rivers, as a rule, are distinguished by the softness of the water and the low content of salts in it. In spring, they are characterized by abundant floods, after which the river enters its usual banks. A similar picture is observed after heavy rains.

Glacial nutrition

The main source of water in the river may be a mountain glacier, the melting of which replenishes the water level in the channel. Such rivers originate on the high peaks of the mountains, covered with a multi-meter layer of ice. In summer, when the glacier actively melts, the water level in them rises, the flow becomes turbulent and erodes the banks, carrying down fertile soil.

Therefore, as a rule, glacial rivers are not popular with the population, and their banks are deserted and barren. Sometimes glacial river, flowing down from a mountain peak, for many centuries carves a deep gorge in the rocks, the bottom of which becomes its channel.

underground food

On the plains and in the lowlands there are rivers that feed mainly from underground sources. There are not so many of them, and their diet is still not well understood. It has been established that underground power can be ground, i.e. coming from the upper aquifer, in which rainwater absorbed into the soil accumulates, or artesian, coming from a natural artesian well.


Underground feeding is typical for small streams, but large water flows are supplied mainly from tributaries.

Types of river feeding. The nature of river nutrition with water is determined by the complex natural conditions. The following types of river nutrition are distinguished: rain, snow, glacial and soil.

Rain nourishment comes either from periodic rains during certain seasons of the year, or from short-term heavy rains. This type of food is predominant on the rivers of the southwestern part of the Caucasus, Crimea, Carpathians and some other regions of the southern part of the European territory of the CIS. Periodic summer rains play a significant role in feeding many rivers of Eastern Siberia and Far East(Amura, Zei, etc.).

Heavy rains are observed in summer and autumn in various regions of the European part of the CIS. Due to their high intensity, they are able to cause rises in water levels in the rivers of small basins, exceeding spring ones.

Snow feeding is predominant on most rivers. The basins of these rivers occupy more than ¾ of the territory of the CIS. Despite the relatively short duration of snowmelt, snow-fed rivers receive up to 60–80% of the total volume of water flowing through them per year during the spring flood.

Glacial feeding is characteristic of rivers highlands Caucasus and Central Asia. It comes from the melting of glaciers and eternal snows in the mountains. Glacier-fed rivers have summer floods, often with sharply pronounced diurnal level fluctuations due to temperature changes during the day.

Groundwater is fed either from shallow groundwater, or from groundwater located at considerable depths. In its pure form, ground food is very rare. As a rule, ground and underground waters serve as a source of river nutrition during periods of decrease or absence of surface runoff.

Many lowland rivers are fed mainly by groundwater in summer, and in winter this type of food is the only one for them.

In the formation of river runoff in different periods of the year, different kinds nutrition. For example, r. The Kuban has snow in the spring due to the melting of snow in the right-bank flat part of the basin; V summer months– glacial nutrition with Caucasus mountains; in autumn - rain feeding from intense downpours and in winter - ground feeding.

Levels and costs mode. The level of water in a river is the elevation of the water surface above a certain conditional horizontal plane.

Water levels in rivers are constantly changing. The main reason for fluctuations in levels is the difference in the amount of water entering the rivers in different periods of the year. In addition to the magnitude of the water discharge, a number of other factors can influence the height of the level: the presence of ice cover, erosion of the channel and the deposition of sediments, sea tides in the mouth sections of rivers, natural backwater from another river, artificial backwater from hydraulic structures, etc.



The annual chart of water level fluctuations during the year is compiled according to actual observations (Fig. 8.3).

To analyze long-term fluctuations in the level, several lines are plotted on one graph, characterizing the change in level in different years. The nature of the level fluctuation depends primarily on the feeding regime of the river.

Plain rivers with predominant snow supply are characterized by a large rise in levels in the spring due to snowmelt and relatively low water levels in the rest of the year. On many of them, level rises are observed in the autumn period due to falling rains, and on small rivers of this group, level rises caused by rains are also observed in the summer months.

Rice. 8.3. Annual chart of water level fluctuation

Large rivers with predominant rain or glacier feeding are characterized by an extended period of high levels in the summer and autumn months. Small mountain rivers with rain or glacier feeding, sharp short-term rises in levels from showers and snowmelt in the mountains during different periods of the year are characteristic. Often, these rivers experience intense daily level fluctuations.

Rivers flowing from lakes or swamps have a smooth course of levels. Due to the regulating role of lakes and swamps, the rise in levels caused by the spring flood extends on these rivers until mid-summer.

The most important characteristic river level regime is the amplitude of fluctuations, i.e. the difference between highest and lowest levels for a certain period of time. There are amplitudes of fluctuations in annual levels, long-term and individual periods of the year. The amplitude of long-term level fluctuations in large rivers reaches 15–20 m or more.

Fluctuations in water levels in the river are due to changes in flow. A graph depicting the relationship between flow and level in a particular section of a river is called a flow curve.

Having annual schedule level fluctuations in the considered section of the river and the flow curve, it is easy to establish the average daily flow for all days of the year. According to the found values ​​​​of average daily flows, an annual graph of their change is built, which is called a hydrograph. Since there is a direct relationship between the flow rate and the level, the hydrograph has a shape similar to the graph of level fluctuations.

Phases in river mode. Characteristic levels and flow rates of water. In the water regime of rivers, a number of characteristic phases can be distinguished, each of which has certain characteristics.

On rivers with predominant snow supply, such phases are: spring flood, summer low water, summer-autumn rain floods and winter low water.

The spring flood is the main phase in the water regime of most rivers. It is characterized by a sharp rise in the water level and a less steep decline. On large rivers, the spring flood lasts from 1.5 to 3 months, and on small and medium rivers - from 10–15 to 30–45 days.

Summer low water begins after the end of the spring flood and lasts until the onset of autumn rains. This phase is characterized by low and stable levels in most rivers. Some small rivers of the southern and southeastern regions of the European part of the CIS in summer period dry up.

Autumn rain floods are observed on many rivers of the European part of the CIS, western and eastern Siberia. They are caused by an increase in precipitation and a simultaneous decrease in evaporation from the surface of river basins.

Winter low water coincides on most lowland rivers with the period of freezing. The lowest water consumption is observed at the end of winter. Small northern rivers sometimes freeze to the bottom in winter.

The main characteristics of each of the listed phases in the river regime are: its duration, the magnitude of the characteristic levels and discharges, the dates of the onset and end of the phase. Along with the average values ​​of these characteristics, it is often necessary to know their possible fluctuations over time. multi-year period.

The water regime of the river in each year and over a long period is characterized by the following main levels:

highest level spring flood;

highest and the lowest levels spring ice drift;

the highest and lowest levels of river ice clearance;

the lowest and middle low water levels;

the highest and lowest levels of summer and autumn floods;

average winter level.

The main characteristic discharges of the river include: the average annual discharge, the maximum discharges in the spring flood and in the summer-autumn floods, the minimum discharges in the summer and winter low flows.

Winter regime of rivers. With the onset of cold weather, rivers in most of the CIS freeze over. The duration of freezing depends on the intensity of the cooling and the speed of the current. On small rivers, it is 3–7 days, and on large rivers, 8–15 days. Quite often, the process of freezing of rivers is accompanied by an autumn ice drift.

During winter, the ice thickness gradually increases, reaching 0.6–1.0 m on the rivers of the central and northern regions of the European part of the CIS and 1.0–1.5 m on the rivers of Siberia.

In the spring, as a result of snowmelt, the opening of the rivers begins, followed by ice drift. The latter lasts from 1–3 days on small rivers, up to 8–10 days on large ones. The nature of the opening of the rivers during the spring ice drift depends primarily on geographical location rivers. On rivers flowing from north to south, the lower reaches are first released from the ice cover, which ensures unhindered movement of ice from the upstream areas. Therefore, the ice drift on these rivers is relatively calm. On rivers flowing in a northerly direction, ice drift conditions are very difficult. Later, the opening of the lower sections of these rivers prevents ice drift and ice jams form in the upstream sections, causing significant rises in water levels, often leading to floods.


1. Climate classification by A.I. VOEIKOV (1884)

Having studied the influence climatic conditions, intra-annual flow distribution A.I. Voeikov concluded: “ceteris paribus, the country will be the richer flowing waters the more precipitation and less evaporation.

The classification is based on the thesis: “rivers are a product of the climate”. He divides rivers into 4 groups and 9 types.

Let's take a closer look at a brief description of all types of rivers in the world.

1 group – MELT FEED – 3 types.

1. Rivers fed by melting snow, on the plains and in low mountains up to 1000 meters. These are the rivers of the North-East of Siberia, the northern part of North America. The rivers flow in the area of ​​permafrost, the filtration is insignificant, the snow cover is established for 8-10 months. There are spring floods caused by melt water.

2. Powered by melting snow in the mountains. These are the rivers of Central Asia. Regular floods are observed on these rivers, the size of which depends on the amount of snow (snow reserves) and the course of summer air temperatures (rapid growth - intensive snowmelt).

3. Powered by melting snow in spring and early summer. These are the rivers of countries with severe and snowy winters. They have a well-defined flood in the spring from melting snow. (European part of Russia, Western Siberia, Scandinavia, Belarus, East Germany, northern part of the USA).

2 group – RAIN FEEDING – 4 types.

4. From rains with high water in warm time year (summer). These are the rivers of areas where tropical and monsoon rains fall. Precipitation is unevenly distributed throughout the year. Falls predominantly in summer time and create significant floods. In winter, the rivers are shallow - they are fed mainly by groundwater (the Amur, Selenga, Amazon, Congo, Nile rivers).

5. Rivers fed by winter rains. Precipitation is relatively evenly distributed throughout the year. The water content of these rivers increases during the cold season, but in general, river level fluctuations are small. Summer precipitation does not cause an increase due to evaporative losses (rivers of Central and Western Europe).

6. Rivers fed by abundant winter rains during the cold season. In summer, there is little rainfall, the rivers dry up ( Southern Europe, north coast of Africa, California, Chile).

7. The absence of rivers due to the dryness of the climate (rivers of the largest deserts in the world - the Sahara, the Arabian Peninsula, Central Asia). At large quantities precipitation, temporary streams appear along the depressions of the eolian relief, along the gullies. Water flows into the basins.

3 group – TALO-RAIN NUTRITION – 1 type.

8. Drying rivers, fed by rains on a short time of the year, and in the rest of the year the rivers dry up or turn into separate lakes-puddles along the hollows in the channel (the rivers of the Steppe Crimea, the lower reaches of the Kura, the Araks, part of Mongolia, the northern part of Kazakhstan).

4 group – SUB-GLACY NUTRITION -1 type.

9. Rivers fed from under continental ice, when it melts in summer. The water mass of the World Ocean warms up in the summer, then it warms up the coastal part of the continents, which causes melting of the continental ice at the bottom (streams of Antarctica, Greenland, the northern coast of the Arctic).

Classification by M.I. LVOVICH (for the CIS rivers).

The classification is based on two criteria:

power supplies;

· intra-annual flow distribution.

They characterize the origin of the river runoff (its genesis) and the zonal geographical regularities of the water regime of the rivers. The classification uses the method of quantifying the share of individual food sources in the annual runoff, which makes it possible to genetically analyze the water regime of rivers and classify them according to food sources.

For a quantitative assessment of each source of food, M.I. Lvovich used the method of dividing the hydrograph and identifying types of food, taking into account the course of air temperatures and precipitation precipitation(snow, rain, hail, etc.).

This classification of the water regime of rivers according to the predominant type of food and seasons of the year with a predominant runoff can be represented as follows:

M.I. Lvovich identified 20 types of water regime and 4 main areas for the CIS territory: snow, rain, predominantly glacial and mixed nutrition. An index was given for each of the 20 types. For example, when writing D 3 L this means - exclusively rain food in summer; C 2 V- mostly snowy in spring, etc.

His typological scheme is based on combinations of food sources with the distribution of runoff according to the seasons of the year.

The distribution of rivers on the territory of the CIS by sources of food is subject to a certain pattern. Most of the territory of the CIS is occupied by river basins of snow, mainly snow and mixed with a predominance of snow supply. On the plains it wears zonal character.

In the extreme south, there are areas of pure snow supply ( From 3), because rains do not give runoff due to the dryness of the climate, groundwater lies deep and does not take part in the feeding of rivers (the rivers Bol. and Mal. Uzen, Eruslan, rivers of northern Kazakhstan, etc.).

Further north, the proportion of snow supply decreases ( From 2) , because underground runoff and precipitation increase. With advancement to the north, the share of ground food decreases and the share of rain food increases (Asian part of Russia, Vilyuy River).

In the north-west of the European part of Russia, mixed-flow rivers flow ( From 1).

There are fewer rain-fed rivers. They flow through the Colchis and Lankaran lowlands, in the Far East.

IN mountainous areas, above the boundary of eternal snows (nival zone), the rivers are fed by glaciers.

Classification by B.D.ZAYKOV.

This classification is based on the characteristics of the water regime of the rivers B.D. Zaikov divided all the rivers of the CIS into 3 groups and 10 types.

The most common rivers in the CIS with spring floods, but depending on the nature of the flood, its duration and the regime of the rivers in the rest of the year, the groups are divided into the following types:

1 group– rivers with SPRING FLOW

Types : 1. Kazakh;

2. Eastern European;

3. West Siberian;

4. East Siberian;

5. Altai.

2 group

Types: 6. Far East;

7. Tien Shan.

3 group– rivers with FLOOD REGIME

Types: 8. Black Sea;

9. Crimean;

10. North Caucasian.

a brief description of types of rivers by the nature of the water regime

1 group– rivers with SPRING FLOW

1. Kazakh . Has a pronounced spring flood lasting less than 1 month, rare and short floods

during the spring and autumn periods. Low flow in spring, summer and autumn (rivers of the Aral-Caspian basin and the southern Trans-Volga region).
2. Eastern European . It has a high, longer flood lasting 1-3 months. Rain floods in summer, heavy rains in autumn (rivers of the Russian Plain).
3. West Siberian . It has a low, stretched spring flood lasting up to 4 months. In autumn - low rain floods (rivers Ob, Ket, Vasyugan, etc.).
4. East Siberian . It has a high spring flood, summer-autumn floods, low winter low water, freezing in winter to the east of the Yenisei (Vitim, Indigirka, Kolyma, etc.).
5. Altai . It has a low, stretched comb-type flood, increased summer-autumn runoff, low winter low water (rivers of Altai and Central Asia).

2 group– rivers with FLOOD IN SUMMER TIME

3 group– rivers with FLOOD REGIME

For large and largest rivers (Ob, Yenisei, Lena), the features of the water regime change in different climatic zones.

Genetic classification of P.S.KUZIN.

This is a classification of the rivers of the CIS according to the main phases of the water regime, based on geographical zoning. The essence of this classification lies in the connection of the main types of water regime with hydrological zones, which are a reflection on earth's surface belts. Moreover, not only individual elements of the river regime, but also the main phases of the water regime are subject to geographical zonality.

The classification is based on the following principles:

type of river feeding and phases of the water regime;

the nature of the relief;

geographic areas.

Kuzin P.S. divides all the rivers of the CIS into 3 types that have a zonal character.

Kuzin P.S. considered the selected types of river regime as categories expressing the main features of the water regime of the CIS rivers.

By the nature of the relief rivers are divided into:

1) mountain (with manifestation altitudinal zonality in the distribution of elements of the water regime);

2) flat (with the manifestation of latitudinal zonality of the elements of the water regime).

Hydrological zones allocated in accordance with geographical zonality, the boundaries of hydrological zones coincide with the boundaries geographical areas. Kuzin P.S. 6 hydrological zones have been identified: arctic, tundra, forest, steppe, semi-desert and desert.

This classification made it possible to bring into a system disparate information on rivers and to explain the regularities in the change in the main phases of the water regime across the territory and to establish the boundaries of hydrological zones and regions.