The regime of the river is the type of feeding of the river flood flood. Read on Mobile Reading mode. Thermal regime of rivers

The river is a natural permanent water stream(watercourse) of significant size with a natural flow along the channel (the natural deepening it has developed) from the source down to the mouth and fed by surface and underground runoff from its basin.

The rivers are part of hydrological cycle. The water in the river is usually collected from surface runoff resulting from atmospheric precipitation from a certain area bounded by a watershed (river basin), as well as from other sources, for example, groundwater reserves, moisture stored in natural ice(during the melting of glaciers) and snow cover.

In places of natural or artificial obstacles to the flow of the river, reservoirs arise (flowing lakes or artificial seas). Limnology (Greek λίμνε - lake, λόγος - study) or lakes science is a branch of hydrology, the science of physical, chemical and biological aspects of lakes and other fresh water bodies, including reservoirs. In turn, rivers are the subject of one of the largest sections of land hydrology - river hydrology or potamology (from ancient Greek ποταμός - river, λόγος - teaching - literally the science of rivers), which studies the structure of river networks, river runoff, morphometry river basins etc. As a rule, rivers make their way and flow along the zones of least stress and resistance - along tectonic faults.

Long time energy fast rivers and waterfalls are widely used in human economic activity as a source of renewable energy for the operation of water mills and hydroelectric turbines.

General information

In each river, the place of its origin is distinguished - the source and the place (site) of the confluence with the sea, lake or confluence with another river - the mouth.

Rivers directly flowing into oceans, seas, lakes or lost in sands and swamps are called major; flowing into the main rivers - tributaries.

The main river with all its tributaries forms a river system characterized by density.

The land surface from which the river system collects its waters is called the catchment area, or catchment area. The catchment area together with the upper layers crust, including the given river system and separated from the others river systems watersheds is called a river basin.

Rivers usually flow in elongated low relief forms - valleys, the lowest part of which is called a channel, and part of the bottom of the valley, filled with high river waters, is a floodplain or floodplain terrace.

In the channels, deeper places alternate - stretches and shallow areas - rifts. Line greatest depths the channel is called the thalweg, close to which the fairway usually passes; the line of the highest flow rates is called the rod.

The bank is called the boundary of the river watercourse, depending on the location along the stream relative to midline watercourse channels distinguish between the right and left banks of the watercourse.

The difference in height between the source and the mouth of the river is called the fall of the river; the ratio of the fall of the river or its individual sections to their length is called the slope of the river (section) and is expressed as a percentage (%) or in ppm (‰).

On the surface the globe rivers are distributed extremely unevenly. On each continent, you can outline the main watersheds - the boundaries of the areas of flow entering the various oceans. The main watershed of the Earth divides the surface of the continents into 2 main basins: the Atlantic-Arctic (runoff from the area of ​​which enters the Atlantic and Arctic oceans) and the Pacific (runoff into the Pacific and Indian oceans). The volume of runoff from the area of ​​the first of these basins is much larger than from the area of ​​the second.

The density of the river network and the direction of the flow depend on the complex of modern natural conditions, but often, to one degree or another, retain the features of previous geological eras. The river network reaches its greatest density in equatorial belt where flow greatest rivers the world - Amazon, Congo; in tropical and temperate zones, it is also high, especially in mountainous regions (Alps, Caucasus, Rocky Mountains etc). In desert areas, episodically flowing rivers are widespread, occasionally turning into powerful streams during snowmelt or intense rainfall (rivers of flat Kazakhstan, Sahara Oued, Creek (drying up river) and Australia, and others).

Classification

Classification of rivers by size

• Large rivers are lowland rivers with a basin area of ​​more than 50,000 km2, as well as rivers predominantly mountainous with a catchment area of ​​more than 30,000 km2. As a rule, their basins are located in several geographic zones, and the hydrological regime is not typical for each river. geographic area separately.
• Medium rivers are lowland rivers, the basins of which are located in the same hydrographic zone, having an area of ​​2,000 to 50,000 km2, the hydrological regime of which is characteristic of the rivers of this zone.
• Small rivers are rivers whose basins are located in the same hydrographic zone, have an area of ​​no more than 2000 km2, and the hydrological regime of which, under the influence of local factors, may not be typical for the rivers of this zone.

Topographic classification

Depending on the topography of the area within which the rivers flow, they are divided into mountain and flat. On many rivers, mountainous and flat areas alternate.

• Mountain rivers, as a rule, are characterized by large slopes, rapid currents, flow in narrow valleys; erosion processes prevail.
• Plain rivers are characterized by the presence of channel meanders, or meanders, formed as a result of channel processes. On lowland rivers, areas of erosion of the channel and accumulation of sediments on it alternate, as a result of which settlements and rifts are formed, and deltas at the mouths. Sometimes branches branch off from the river merge with another river.

Hydrobiological classification

Classification of water sports possible

According to the International Scale of River Difficulty, there are six difficulty levels.

Classification according to the configuration of the tributary network

There are 12 classes of rivers according to the nature of the network of tributaries, determined by the Straler Number. The sources of the rivers along this system belong to the first class, and the Amazon River to the twelfth.

Use of rivers

Since ancient times, rivers have been used as a source fresh water, for obtaining food (fishing), for transport purposes, as a protective measure, delimiting territories, as a source of inexhaustible (renewable energy (rotation of machines (for example, a water mill) or turbines of a hydroelectric power station), for bathing, irrigation of agricultural land and as a means of getting rid of from waste.

For thousands of years the rivers have been used for navigation purposes. The earliest evidence of river navigation is from the Indus Valley civilization in the northwest. modern territory Pakistan around 3 300 BC. The use of river navigation in human economic activities provides cheap (water) transport, and is still widely used on the largest rivers in the world, such as the Amazon, Indus, Ganges, Nile and Mississippi (river). Quantity harmful emissions produced by river vessels are not clearly regulated or regulated around the world, which contributes to the constant release into the Earth's atmosphere a large number greenhouse gases, as well as an increase in the incidence of malignant neoplasms in the local population as a result of constant inhalation of harmful particles emitted into the air by water transport.

The rivers are playing important role in defining political boundaries and protecting the country from the invasion of external enemies. For example, the Danube was part of the ancient border of the Roman Empire, and today this river forms most of the border between Bulgaria and Romania. The Mississippi in North America and the Rhine in Europe are the main borders separating the east and west of the countries located on the respective continents. In southern Africa, the Orange and Limpopo rivers form the boundaries between provinces and countries along their routes.

Flood

A flood (or flood) is part of the natural cycle of a river - one of the phases water regime rivers, repeating annually in the same season of the year - a relatively long and significant increase in the water content of the river, causing a rise in its level. Usually accompanied by the release of water from the low-water channel and flooding of the floodplain.

Flood - the phase of the river's water regime - a relatively short-term and non-periodic rise in the water level in the river, caused by increased melting of snow, glaciers or an abundance of rain. Unlike floods, floods do not recur periodically and can occur at any time of the year. A significant flood can cause flooding. In the process of flood movement along the river, a flood wave is formed.

Flooding - flooding of an area as a result of a rise in the water level in rivers, lakes, seas due to rains, rapid melting of snows, wind surges on the coast and other reasons, which damages the health of people and even leads to their death, and also causes material damage... Wind surges of water in sea estuaries and on windy areas of the coast of seas, large lakes, reservoirs. Possible at any time of the year. They are characterized by a lack of periodicity and a significant rise in the water level.

Most of the process of erosion of river beds and sedimentation of washed-out rocks on the respective floodplains occurs during floods. In many developed areas of the world economic activity changed the shape of river beds, influencing the magnitude (intensity) and frequency of floods. Examples of human impact on the natural state of rivers include the erection (creation) of dams, the straightening of the channel (construction of canals) and the drainage of natural wetlands. In most cases, mismanagement of humans in river floodplains leads to a sharp increase in the risk of floods:

• artificial straightening of the river channel allows water to flow downward faster, increasing the risk of flooding downstream;
• Changing the nature of the river floodplain (straightening) removes natural flood protection reservoirs, thereby increasing the risk of floods in the lower reaches of rivers;
• the creation of an artificial embankment or dam can only protect the area lying downstream of the river (behind the dam), and not those areas that are located upstream;
• the presence of a dam, as well as straightening and strengthening of banks (for example, creating embankments, etc.) can also increase the risk of flooding in areas upstream of the river. As a result, the outflow becomes difficult and the pressure increased on the downdraft associated with an obstacle to the normal outflow of water due to the narrowness of the channel between the reinforced banks.

Underground river

Most, but not all, rivers flow on the surface of the Earth. Underground rivers carry their streams underground in caves. Rivers of this kind are often found in regions with limestone (karst) deposits in geological formations. In addition, there are caves formed in the body of glaciers by melt water. Such caves are found on many glaciers. Melted glacial waters are absorbed by the body of the glacier along large cracks or at the intersection of cracks, forming passages sometimes passable for humans. The length of such caves can be several hundred meters, the depth - up to 100 m or more. In 1993, a giant glacial well "Izortog" with a depth of 173 m was discovered and investigated in Greenland, the inflow of water into it in the summer was 30 m3 or more. Due to the presence of a "roof" formed from geological rocks impermeable to water (or ice) and high pressure directed towards the overlying massifs of the glacier, a so-called topographic gradient is created - such flows are even capable of flowing uphill. Another type of glacial caves are caves formed in a glacier at the outlet of intraglacial and subglacial waters at the edge of glaciers. Melt water in such caves can flow both over the glacier bed and over glacial ice.

Water is usually found in many caves, and karst caves owe their origin to it. In caves you can find condensate films, drops, streams and rivers, lakes and waterfalls. Siphons in caves significantly complicate the passage, require special equipment and special training. Underwater caves are not uncommon. In the entrance areas of caves, water is often present in a frozen state, in the form of ice deposits, often very significant and perennial.

Underground River Puerto Princesa - An underground river near the Philippine city of Puerto Princesa, on the island of Palawan (Philippines). This river, about 8 km long, flows underground, in a cave, in the direction South China Sea... Created in the area of ​​its location National park the underground river of the city of Puerto Princesa (Puerto Princesa Subterranean River National Park) is a nature reserve located 50 km from the city. The park is located in the Saint Paul Ridge in the northern part of the island and is bounded by the Saint Paul Bay and the Babuyan River. A similar river is known on the Yucatan Peninsula in Mexico, but this one is recognized as the largest. Both underground rivers owe their origin to the karst relief. The water in these rivers changed its direction of flow, finding a way down, thanks to the dissolution of carbonate rocks and the formation of an extensive underground river system.

The Hamza River (port. Rio Hamza) is the unofficial name for an underground current under the Amazon bed. The opening of the "river" was announced in 2011. The unofficial name is given in honor of the Indian scientist Wali Hamza, who has been researching the Amazon for over 45 years.

The largest rivers in the world

Greatest rivers in the world

№	Name	Length (km)	Basin area (thousand km²)	Average water discharge at the mouth (thousand m³ / s)	The highest water discharge at the mouth (thousand m³ / s)	Solid effluent (million tons / year)
1.	Amazon
2.	Nile
3.	Yangtze
4.	Mississippi - Missouri
5.	Yellow he
6.	Ob (with Irtysh)
7.	Parana (from the origins of Paranaiba)
8.	Mekong
9.	Amur (from the origins of Argun)
10.	Lena
11.	Congo (with Lualaba)
12.	Mackenzie (from the origins of Peace River)
13.	Niger
14.	Yenisei (from the origins of the Small Yenisei)
15.	Volga
16.	Indus
17.	Yukon
18.	Danube
19.	Orinoco
20.	Ganges (with Brahmaputra)
21.	Zambezi
22.	Murray
23.	Dnieper

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The flow of rivers and their water regime during the year bears the stamp of zoning, since they are determined primarily by the conditions of feeding. The first classification of rivers by feeding conditions and water regime was created by A.I. Voeikov in 1884. Later it was improved by M.I. quantify the role of individual sources of river feeding and the seasonal distribution of runoff. Under certain conditions, each of the power sources can be almost exclusive if its share is more than 80%; may prevail (50-80%) or prevail over others (less than 50%). The same gradations are used by him for the river runoff according to the seasons of the year. According to the combination of power sources (rain, snow, underground, glacial) and the seasonal distribution of runoff, they identified six zonal types of river water regime on the Earth, which are well expressed on the plains.

Equatorial rivers have abundant rain food, a large and relatively uniform runoff throughout the year, its increase is observed in the fall of the corresponding hemisphere. Rivers: Amazon. Congo, etc.

Tropical rivers. The runoff of these rivers is formed by monsoon summer rains in the subequatorial climatic zone and mainly summer rains on east coasts tropical belt, therefore, the summer flood. Rivers: Zambezi, Orinoco, etc.

Subtropical rivers in general, they are mainly fed by rain, but according to the seasonal distribution of runoff, two subtypes are distinguished: on the western coasts of the continents in mediterranean maritime climate the main runoff is winter (Guadiana, Guadalquivir, Duero, Tahoe, etc.), on the eastern coasts in a monsoon climate, the runoff is summer (tributaries of the Yangtze, Yellow River).

The rivers are of a temperate type. Within the moderate climatic zone four subtypes of rivers are distinguished according to their sources of water supply and seasonal distribution of runoff. On the western coasts, in the maritime climate near the rivers, it is predominantly rain fed with an even distribution of runoff throughout the year with a slight increase in winter due to reduced evaporation (Seine, Thames, etc.); in areas with a transitional climate from maritime to continental, rivers have mixed nutrition with a predominance of rain over snow, with a low spring flood (Elbe, Oder, Vistula, etc.); in areas continental climate rivers are mainly fed by snow and spring floods (Volga, Ob, Yenisei, Lena, etc.); on the east coasts with monsoon climate the rivers are mainly fed by rain and summer floods (Amur).

Scheme of river classification according to food sources (according to M.I.L'vovich).

Subarctic rivers have predominantly snow supply with an almost complete absence of underground due to permafrost... Therefore, many small rivers freeze to the bottom in winter and have no runoff. The high water on the rivers is mainly summer, since they open up in late May - early June (Yana, Indigirka, Khatanga, etc.).

Polar type rivers v short period the summers are glacier-fed and runoff, while most of the year they are frozen.

Such types and subtypes of the water regime are typical for lowland rivers, the flow of which is formed in more or less of the same type. climatic conditions... The regime of large transit rivers crossing several natural and climatic zones is more complicated.

Rivers mountain areas regularities of vertical zonality are inherent. As the height of the mountains near the rivers increases, the share of snow and then glacier nutrition also increases. Moreover, in arid climate in rivers, glacial nutrition is the main one (Amu Darya and others), in humid rivers, along with glacial nutrition, rain supply is also carried out (Rona and others). Mountain, especially alpine, rivers are characterized by summer floods.

The most intense and even catastrophic are summer floods on rivers that begin high in the mountains, and in the middle and lower reaches are abundant monsoon rains: Indus, Ganges, Brahmaputra, Mekong, Ayeyarwaddy, Yangtze, Yellow River, etc.

B. D. Zaikov's river classification

Along with the classification of rivers by M.I. Lvovich, the typification of rivers according to the hydrological regime of B.D.Zaikov is popular in Russia. Under hydrological regime in this case, we understand the distribution and nature of the passage of various phases of the water regime: high water, low water, floods, etc. According to this typification, all rivers in Russia and the CIS are divided into three groups:

1. with spring floods;
2. with summer floods and floods;
3. with a flood regime.

Within these groups, according to the nature of the hydrograph, rivers with different types regime.

Among the rivers with spring flood there are rivers: of the Kazakh type (a pronounced short flood and an almost dry low-water period most of the year); Eastern European type (high short flood, summer and winter low water); West Siberian type (low extended flood, increased runoff in summer, winter low water); East Siberian type (high flood, summer low water with rain floods, very low winter low water); Altai type (low uneven extended flood, increased summer runoff, winter low water).

Among the rivers with summer flood the following rivers are distinguished: of the Far Eastern type (low extended flood with floods of monsoon genesis, low winter dry season); Tien Shan type (low extended flood of glacial genesis).

WITH flood regime the rivers are distinguished: of the Black Sea type (floods throughout the year); Crimean type (floods in winter and spring, summer and autumn low water): North Caucasian type (floods in summer, low water in winter).

Forecast of water content of rivers and their regime during the year has great importance to address issues of the rational use of water resources of countries. It is very important to forecast the runoff during floods, which in some years are extremely high (for example, on the rivers of the Primorsky Territory in August 2000) and lead to negative consequences.

The word "regime", probably, not only in me evokes negative associations. Regimes of pioneer camps, regime enterprises, in general, a prison and nothing good. Interestingly, the rivers, it turns out, also have their own regime, and in this case the word has a completely different meaning.

What is meant by the term "river regime"

Most of the parameters of the river change depending on the season. In the spring, when thousands of streams of melt water flow down to the rivers, the level and chemical composition rivers, and sometimes the speed of the current. In summer, a different picture is observed - the channel becomes shallow, and the remnants of the water take on a greenish tint, since during this period algae multiply. In autumn, the level rises again, and in winter the rivers are covered with ice. All these transformations fully reveal the meaning of the term, and in the language of science, these are seasonal changes in a number of parameters of a particular river. Hydrology distinguishes between 3 phases, which determine the type of water regime. So this:

• High water. At the same time, there is a sharp increase in the volume of the flow, which is repeated annually.
• Flood. In principle, this is the same flood, but with all the suddenness of floods, they are extremely short-lived.
• Low water. The water level becomes minimal, and the only thing that prevents the flow from completely disappearing is underground springs.

As for the reasons that lead to changes, they are very diverse, but there are also key ones:

• the climate and nature of the river's feeding;
• relief and properties of the channel rocks;
• plants, animals and humans.

Water regimes of Russian rivers

Our Motherland is characterized by rivers of the following regimes, which, by the way, are determined by the peculiarities of the local climate. So this:

• Spring flood. For example, the Volga and other rivers within temperate latitudes.
• Summer floods and floods. For example, the Amur, as well as other rivers located in the Far East.
• Flood regime - Terek, like other rivers that flow within the North Caucasus.

As for my hometown Astrakhan, then for the Volga, on the banks of which it is located, the first type is inherent, that is, the spring flood.

Nutrition rivers are called the flow of water into their channels; it is brought by surface and underground runoff. There are three types of food: rain, melted snow and melted glacial waters, or, in abbreviated form, rain, snow and glacial. Until recently, ground food was also isolated. However, it is quite obvious that it is part of the rain, snow or glacier. Only groundwater ensures the continuity of the flow of rivers and regulates their level. In those areas where atmospheric moisture is insufficient and the soil is not wetted by precipitation, rivers dry up for a season without rains or even flow only during the spring thaw of snow.

The total volume of water entering the channel depends on river flow. For example, the average annual discharge of the Ural River with a length of 2534 km is only 360 m 3 / s, while in the Zambezi (length 2660 km) already at the Victoria Falls (1200 km from the mouth) it is 1400 m 3 / s.

The seasonal distribution of the water entering the channel is very important. Associated with him fluctuations in river levels. So, the minimum discharge of the Urals at the same point, for which the average annual discharge is given above, is 13.6 m 3 / s, and the maximum is 13,500 m 3 / s. The Zambezi is full of water in all seasons.

There are the following zonal types of river water regime:

1. Equatorial type. The food is only rain-fed, abundant and uniform throughout the year. During the months of the equinox, there are stormy floods. Such a regime of rivers is ensured by the water balance: precipitation is about 2000 mm, evaporation is about 1000 mm, up to 50% is spent on runoff, underground recharge is abundant, sometimes up to 50% of the total runoff, since it is powerful soil cover absorbs a lot of moisture.

2. Subequatorial, or savanna, type. The food is only rain-fed. Most of the precipitation (900-1800 mm) falls during the rainy season. In dry
In the season, evaporation is so great that by the end of the season all the reserves of soil moisture are depleted, and the flow of water in the rivers becomes extreme and the rivers dry up. The first rains completely saturate the soil, and only after that the discharge in the rivers increases sharply. From the middle of the rainy season, the level of the rivers rises rapidly and becomes very high.

3. Tropical desert. Tropical deserts are endless. All precipitation (less than 200 m) is spent on evaporation. Short torrential rains can give only surface runoff in the form of flash floods, moisture infiltration is insignificant and is observed only in sands or fractured limestones. Groundwater is not formed due to modern precipitation.

4. Subtropical Mediterranean. The rivers are fed exclusively by rain. Most of the precipitation falls in the winter. At this time of the year, the level of the rivers rises. In the dry season, the rivers are shallow, many dry up. With high evaporation (up to 90% of the total precipitation), infiltration in the ground is low and underground feeding of rivers practical does not, they only carry surface water. Naturally, their regime is uneven, flood.

5. Subtropical monsoon. The rivers are also fed by rain, but in contrast to the Mediterranean type of precipitation there is more precipitation and the rivers are full of water. Precipitation occurs in both winter and summer, with the maximum summer monsoon rains; the flow of rivers at this time is flood, stormy; in winter, the level drops. For example, the amplitude of the Yellow River level on the plain reaches 5 m with a maximum in July-August and a minimum in January-February.

6. Moderate marine, or Western European. The food is almost exclusively rain-fed. It is relatively evenly distributed over the seasons. Precipitation is consumed approximately in half for evaporation and river runoff. The underground supply also accounts for about half of the total runoff. In winter, precipitation is slightly higher and evaporation is less. The rivers are always full-flowing, the maximum level is in winter.

7. Moderate continental or Russian type. Food is rain and snow. In summer and autumn, only rain water, in winter only ground water, in spring - with melt water and less rain. Underground recharge makes up 25 to 30% of the total runoff; it ensures the flow of rivers both under ice in winter and in hot summer months... The water regime of the rivers is uneven: a stormy spring flood is replaced by a low summer low-water period; in autumn, water content increases due to reduced evaporation and decreases in winter - winter low-water period. On marshy plains such as Western Siberia, the flood lasts for a considerable time.

8. Moderate semi-desert or Kazakh. It is fed by rain and snow, melted snow waters of the spring period prevail. Summer rains do not soak the soil, and the groundwater supply is so little that in summer many rivers dry up, in others the runoff is so small that the water becomes brackish, and the rivers do not reach the sea or lake and end in blind mouths (Turgai, Irgiz).

9. Moderate desert. Stock only due to spring melt water in the form of short-term streams. The total runoff is close to zero. The rivers are only transitory.

10.Moderate monsoon or Far Eastern. It is fed by rain and snow, the total runoff is significant, about 300 mm; summer due to monsoon rains. In late July - early August, high floods acquire the character of catastrophic floods. The spring melting of snow, unlike the rivers of the Russian type, does not cause floods. The winter low-water period is low. but
groundwater supply still ensures the constancy of even small rivers.

8. Permafrost, or East Siberian. Strong winter frosts, low precipitation, low snow cover and especially permafrost give the water balance and rivers Eastern Siberia significant uniqueness. The layer of precipitation varies from 330 mm at Yana to 540 mm at Vitim. Due to the permafrost, the underground runoff is extremely small: 21 and 58 mm. In the heat of summer, the thawing of the permafrost provides the rivers with another source of food. Food is almost exclusively from snow and permafrost waters; rainfall accounts for 1-2%. For this reason, as well as because of the permafrost, the spring flood is stormy, the level rises by 10-15m. Summer regime is flood from rains. Water freezing to the bottom is characteristic. Small rivers freeze over their entire length, large rivers only on the rifts. Since there is no ground supply in winter due to permafrost, the runoff stops not only on small rivers, but even on Yana, Indigirka, Vilyuya. Ice forms on rivers in winter.

12.Polar. Runoff occurs only in the short polar summer in the form of temporary streams fed by melt water; there are no real rivers.

13.Lake type. It includes the rivers Neva, Svir, St. Lawrence, Nelson, Mackenzie, Angara. They carry almost exclusively lake water, surface and underground runoff are quite small. Rivers-channels are always full-flowing and regulated by huge lakes, their level does not depend on precipitation, slope runoff and snow melting.

14.Mountain type. Mountain rivers are characterized by vertical zonation of feeding and regime. In the highlands, they feed on melted glacial water, so the runoff increases in summer. On the slopes medium height rainwater is added to the melt water, and there is a lot of precipitation in the mountains. In the lower reaches, the regime of the rivers is determined by the nature of the geographic zone in which the foothills of the mountainous country are located.

In the mountain type, two subtypes are distinguished: Central Asian and alpine. The rivers of the deserts of Central and Central Asia and other arid zones do not receive precipitation after leaving the mountains, they flow in transit, in the lower reaches the volume of water in them decreases and they either flow into closed lakes or end in blind mouths. In rivers of the Alpine type - the Alps, the Caucasus, Altai and other mountainous countries of humid zones - the abundant glacial nutrition below is complemented by the equally abundant rainfall. The rivers are full of water.

The river flow consists of flood and steady flow. In providing water to soils, plants, and especially in the water supply of the world's population, a sustainable runoff is important.

Non-periodic fluctuations in the level of rivers. In addition to periodic floods on rivers, there are occasional increases in water mass and rise in levels. These include floods and floods.

Flood is called a rapid, short-term rise in the water level in the river, caused by heavy rainfall, rapid melting of snow, blocking the channel with ice. Down the river, the flood spreads in a wave, high in the frontal part and lowered in the rear. The speed of movement of the flood wave varies from 45 in the mountains to 3 km / h in the plains. Gradually spreading out, the wave fades.

Sometimes floods are accompanied by floods - significant flooding of the area. They are frequent on the rivers Of the Far East, happen on Ohio and Mississippi, on the Danube, Rhone, Po. Floods very often happen on the Neva.

Russia is a country abundant water resources... On its territory there are about 2.8 million rivers and rivulets, the total length of which is 12.4 million kilometers.


Each of them is unique in its own way, possessing its own water composition, channel topography, current speed and other features. Subordinating nature and improving his habitat, a person is obliged to take into account the characteristics of each element of the natural landscape.

This is especially true of our rivers supplying cities and countryside water. Did you know that each, even the smallest, river has its own regime, which obeys its existence?

What is River Mode?

Many parameters of rivers change depending on seasonal changes climate. In spring, when the snow accumulated over the winter melts and turns into water, the rivers increase in volume, change their chemical composition, and often the speed of the current.

In the summer, when scorching heat reigns, and the water in the channel is actively evaporating, the river becomes shallow, and small algae can actively multiply in its waters, coloring it into green color.

In winter, the channel is held down by ice, and aquatic animals settle down to winter, buried in the river silt. All these fluctuations are called the river regime. In the language of science, the regime of each river is cyclical changes in the temperature of its water, level, speed of its flow, water composition and many other parameters.


The river regime is not considered in itself, but in a complex that includes geographic, physical and climatic factors, most characteristic of the area. Greatest influence the regime is influenced by temperature fluctuations, the amount and distribution of precipitation over time, the level of evaporation and infiltration of water through the rocks that make up the channel.

For plain territories, zonal changes are more characteristic natural factors, in accordance with which the regime and water balance of rivers change. Mountain rivers are mainly subject to altitudinal zonality, according to which the parameters of their mode are changed.

River regime phases

Hydrologists distinguish three main phases that make up the regime of any river: low water, high water and floods.

1. - a rise in the level and an increase in water discharge associated with the influx of a large amount of melt or rainwater and repeated annually during the same season. During floods, the river usually overflows its banks and floods the floodplain. The time of the onset of floods depends on local geographic and climatic characteristics.

2. - rise in water level, which is caused by abundant heavy rains or thaws. Unlike floods, floods are characterized by a rapid but short rise in level. In Russia, floods often occur in late summer or autumn, when a period of heavy rainfall begins.


3. - a period of low water content, during which the river is replenished mainly from underground sources. In our climate, hydrologists distinguish between summer and winter low-water periods.

What does the river regime depend on?

The river regime depends on many factors, the most significant of which are:

— geographical position;

- water supply, i.e. sources that replenish the water level in the river (precipitation, groundwater, glaciers, lakes);

— climatic features- dry or humid climate, the dynamics of seasonal temperature fluctuations, the strength and direction of the wind, affecting the water level;

- terrain - flat or mountainous;

- rocks that make up the channel - sand, clay, hard rocks;

- flora and fauna of the river - vegetation and animals can affect the composition of the water, the speed of its flow;

— anthropogenic impact- the presence on the banks of the river of cities and enterprises that discharge wastewater into it and take water for their own consumption.

These are the main factors, the influence of which on the river regime is manifested to the greatest extent. However, there are many less noticeable factors, the influence of which can become decisive under certain conditions.


The ecosystem of rivers is fragile, and any ill-considered impact can unbalance the river regime, causing adverse changes in it.