The country with the largest water resources. Water resources

Introduction

Organization rational use water is one of the most important modern problems protection and transformation of nature. The intensification of industry and agriculture, the growth of cities, and the development of the economy as a whole are possible only if reserves are preserved and increased fresh water. The costs of preserving and reproducing water quality occupy first place among all human costs for environmental protection. The total cost of fresh water is much more expensive than any other type of raw material used.

Successful transformation of nature is possible only with sufficient quantity and water quality. Typically, any project to transform nature is largely associated with some impact on water resources.

Due to the development of the world economy, water consumption is growing at a rapid pace. It doubles every 8-10 years. At the same time, the degree of water pollution increases, i.e., their qualitative depletion occurs. The volume of water in the hydrosphere is very large, but humanity directly uses only a small part of fresh water. All this, taken together, determines the urgency of the tasks of water protection, their paramount importance in the whole complex of problems of use, protection and transformation of nature.

Water resources sushi and their distribution on the planet. Water supply to countries of the world

Water occupies a special position among the natural resources of the Earth. Famous Russian and Soviet geologist Academician A.P. Karpinsky said that there is no more precious mineral than water, without which life is impossible. Water is the main condition for the existence of living nature on our planet. A person cannot live without water. Water is one of the the most important factors, determining the location of productive forces, and very often the means of production. Water resources are the main life-giving resource of the Earth; waters suitable for their use in the world's national economy. The waters are divided into two large groups: waters of land, waters of the World Ocean. Water resources are distributed unevenly across the territory of our planet; renewal occurs thanks to the global water cycle in nature, and water is also used in all sectors of the world economy. It should be noted main feature water is its use directly on the “site”, which leads to water shortages in other areas. The difficulties of transporting water to arid areas of the planet are associated with the problem of financing projects. The total volume of water on Earth is approximately 13.5 million cubic meters, that is, per person there is an average of 250-270 million cubic meters. However, 96.5% is the waters of the World Ocean and another 1% is salty underground and mountain lakes and waters. Fresh water reserves account for only 2.5%. The main reserves of fresh water are contained in glaciers (Antarctica, Arctic, Greenland). These strategic objects are used little, because... Transporting ice is expensive. About 1/3 of the land area is occupied by arid (arid) belts:

· Northern (deserts of Asia, the Sahara Desert in Africa, the Arabian Peninsula);

· Southern (deserts of Australia - Great sandy desert, Atacama, Kalahari).

The largest volume of river flow occurs in Asia and South America, and the smallest in Australia.

When assessing water availability per capita, the situation is different:

· the most abundant river flow resources are Australia and Oceania (about 80 thousand m 3 per year) and South America (34 thousand m 3);

· Asia is the least wealthy (4.5 thousand m 3 per year).

The world average is about 8 thousand m3. Countries of the world endowed with river flow resources (per capita):

· surplus: 25 thousand m 3 per year - New Zealand, Congo, Canada, Norway, Brazil, Russia.

· average: 5-25 thousand m 3 - USA, Mexico, Argentina, Mauritania, Tanzania, Finland, Sweden.

· small: less than 5 thousand m 3 - Egypt, Saudi Arabia, China, etc.

Ways to solve the water supply problem:

· implementation of water supply policy (reducing water losses, reducing water intensity of production)

· attraction of additional fresh water resources (desalination of sea waters, construction of reservoirs, transportation of icebergs, etc.)

· construction treatment facilities(mechanical, chemical, biological).

Three groups of countries most endowed with water resources:

· more than 25 thousand m 3 per year - New Zealand, Congo. Canada, Norway, Brazil, Russia.

· 5-25 thousand m3 per year - USA, Mexico, Argentina, Mauritania, Tanzania, Finland, Sweden.

· less than 5 thousand m 3 per year - Egypt, Poland, Algeria, Saudi Arabia, China, India, Germany.

Functions of water:

· drinking water (for humanity as a vital source of existence);

· technological (in the world economy);

· transport (river and sea transportation);

· energy (hydroelectric power station, power station)

Water consumption structure:

· reservoirs - about 5%

· municipal and household services - about 7%

industry - about 20%

· Agriculture- 68% (almost the entire water resource is used irrevocably).

Several countries have the greatest hydroelectric potential: China, Russia, USA, Canada, Zaire, Brazil. The degree of use in countries around the world is different: for example, in the countries of Northern Europe (Sweden, Norway, Finland) - 80 -85%; V North America(USA, Canada) - 60%); V Overseas Asia(China) - about 8-9%.

Modern large thermal power plants consume huge amounts of water. Only one station with a capacity of 300 thousand kW consumes up to 120 m 3 /s, or more than 300 million m 3 per year. Gross water consumption for these stations will increase approximately 9-10 times in the future.

One of the most significant water consumers is agriculture. In system water management it is the largest water consumer. Growing 1 ton of wheat requires 1,500 m 3 of water during the growing season, 1 ton of rice requires more than 7,000 m 3 . The high productivity of irrigated lands has stimulated a sharp increase in area worldwide - it is now equal to 200 million hectares. Constituting about 1/6 of the total crop area, irrigated lands provide approximately half of agricultural products.

A special place in the use of water resources is occupied by water consumption for the needs of the population. Household and drinking purposes in our country account for about 10% of water consumption. At the same time, uninterrupted water supply, as well as strict adherence to scientifically based sanitary and hygienic standards, are mandatory.

The use of water for economic purposes is one of the links in the water cycle in nature. But the anthropogenic link of the cycle differs from the natural one in that during the process of evaporation, part of the water used by humans returns to the atmosphere desalinated. The other part (component, for example, in the water supply of cities and most industrial enterprises 90%) is discharged into water bodies in the form Wastewater contaminated with industrial waste.

The World Ocean is a storehouse of mineral, biological, and energy resources. The world's oceans are the richest part of the planet in terms of natural resources. Significant resources are:

· mineral resources (iron-manganese nodules)

Energy resources (oil and natural gas)

· biological resources(fish)

· sea water ( salt)

Mineral resources of the World Ocean floor are divided into two groups: shelf resources (coastal part of the ocean) and bed resources (deep ocean areas).

Oil and natural gas are the main types of resources (more than half of all world reserves). More than 300 deposits have been developed and are being intensively used. The main areas of oil production and natural gas There are 9 main marine areas on the shelf:

· Persian Gulf (Kuwait, Saudi Arabia)

· South China Sea (China)

Gulf of Mexico (USA, Mexico)

· Caribbean Sea

North Sea (Norway)

· Caspian Lake

· Bering Sea (Russia)

Sea of ​​Okhotsk (Russia)

The World Ocean is rich in reserves of such an amazing mineral as amber, which is mined on the coast of the Baltic Sea; there are deposits of precious and semi-precious stones: diamonds and zirconium (Africa - Namibia, South Africa, Australia). Known places of extraction of chemical raw materials: sulfur (USA, Canada), phosphorites (USA, South Africa, North Korea, Morocco). In deep-sea areas (ocean bed), iron-manganese nodules are mined ( Pacific Ocean, Indian Ocean).

The energy resources of the World Ocean are expressed in the use of sea tides. Tidal power plants were built on the coasts of those countries, with a daily ebb and flow regime. (France, Russia - Beloe, Okhotsk, Barents Sea; USA, UK).

The biological resources of the World Ocean are diverse in species composition. These are various animals (zooplankton, zoobenthos) and plants (phytoplankton and phytobenthos). The most common include: fish resources (more than 85% of the ocean biomass used), algae (brown, red). More than 90% of fish are caught in the shelf zone in high (Arctic) and temperate latitudes. The most productive seas are: the Norwegian Sea, the Bering Sea, the Sea of ​​Okhotsk and the Sea of ​​Japan. Reserves sea ​​water great. Their volume is 1338 million cubic km. Sea water is a unique resource on our planet. Sea water is rich in chemical elements. The main ones are: sodium, potassium, magnesium, sulfur, calcium, bromine, iodine, copper. There are more than 75 of them in total. The main resource is table salt. The leading countries are: Japan and China. Except chemical elements and microelements, silver, gold, and uranium are mined in the depths of sea waters and on the shelf. The main thing is the fact that sea water is successfully desalinated and consumed in those countries that lack fresh water. inland waters. It should be noted that not all countries in the world can afford such luxury. Desalinated seawater is intensively used by Saudi Arabia, Kuwait, Cyprus, and Japan.

Water resources include all types of water, excluding water physically and chemically associated with rocks and the biosphere. They are divided into two different groups, consisting of stationary water reserves and renewable reserves participating in the water cycle process and assessed by the balance method. For practical needs, mainly fresh water is needed.

As already mentioned, water resources are all the water reserves on the planet. But on the other hand, water is the most common and most specific compound on Earth, because only it can exist in three states (liquid, gaseous and solid).

The Earth's water resources consist of:

· surface waters (oceans, seas, lakes, rivers, swamps) are the most valuable source of fresh water, but the thing is that these objects are distributed quite unevenly over the Earth’s surface. Thus, in the equatorial zone, as well as in the northern part of the temperate zone, water is in excess (25 thousand m3 per year per person). And the tropical continents, which consist of 1/3 of the land, are very acutely aware of the shortage of water reserves. Based on this situation, their agriculture develops only under the condition of artificial irrigation;

· groundwater;

· reservoirs created artificially by man;

· glaciers and snowfields (frozen water from glaciers in Antarctica, the Arctic and snowy mountain peaks). This contains the most most of fresh water. However, these reserves are practically unavailable for use. If all the glaciers are distributed over the Earth, then this ice will cover the earth with a ball 53 cm high, and by melting it, we thereby raise the level of the World Ocean by 64 meters;

· moisture contained in plants and animals;

· vaporous state of the atmosphere.

Availability of water resources:

The world's water reserves are enormous. However, this is predominantly salt water of the World Ocean. Fresh water reserves, for which people's need is especially great, are insignificant (35029.21 thousand km3) and exhaustive. In many places on the planet there is a shortage of it for irrigation, industrial needs, drinking and other domestic needs.

The main source of fresh water is rivers. Of all the river waters on the planet (47 thousand km3, only half can actually be used.

Freshwater consumption is constantly growing, but river flow resources remain unchanged. This creates a threat of fresh water shortage.

The main consumer of fresh water is agriculture, in which its irreversible consumption is high (especially for irrigation).

To solve the problem of water supply, projects for economical water consumption, construction of reservoirs, desalination of sea water, and redistribution of river flow are used; iceberg transportation projects are being developed.

Countries have different levels of water resources. About 1/3 of the land area is occupied by the arid belt, which is home to 850 million people.

· Countries with insufficient water resources include Egypt, Saudi Arabia, Germany;

· with average income - Mexico, USA;

· with sufficient and excess security - Canada, Russia, Congo.

One of the ways to provide the population fresh water- desalination of salt waters. Two thousand years ago, people learned to obtain fresh water from salt water by distillation. The first installations for desalination of sea water appeared at the beginning of the 20th century, for which solar desalination plants were used, for example, in the Atacama Desert (Chile). In the second half of the 20th century, nuclear desalination plants began to be used. They are used most of all by countries with tropical climates: Tunisia, Libya, Egypt, Saudi Arabia, Kuwait, UAE, etc. The countries of the Persian Gulf receive the most desalinated water per capita. In Kuwait, 100% of the water used is desalinated seawater.

Water reserves in the world. List of countries by water resources

A list of 173 countries of the world is presented, ordered by the volume of total renewable water resources according to data [. Data include long-term average renewable water resources (in cubic kilometers of precipitation, renewable groundwater, and surface inflows from neighboring countries.

Brazil has the largest renewable water resources - 8,233.00 cubic kilometers. Russia has the largest reserves in Europe and the second in the world - 4,508.00. Next is the USA - 3,069.00, Canada - 2,902.00 and China - 2,840.00. Full table- see below.

Fresh water. Reserves[Source - 2].

Fresh water- the opposite of sea water, covers that part available water The land in which salts are contained in minimum quantities. Water whose salinity does not exceed 0.1%, even in the form of steam or ice, is called fresh. Polar ice sheets and glaciers contain the largest portion of the earth's fresh water. In addition, fresh water exists in rivers, streams, groundwater, fresh lakes, and also in clouds. According to various estimates, the share of fresh water in total number water on Earth is 2.5-3%.

About 85-90% of fresh water is contained in the form of ice. The distribution of fresh water around the globe is extremely uneven. Europe and Asia, where 70% of the world's population lives, contain only 39% of river waters.

Russia by resources surface waters occupies a leading position in the world. About 20% of the world's lake fresh water reserves and more than 80% of Russia's reserves are concentrated in the unique Lake Baikal alone. With a total volume of 23.6 thousand km³, about 60 km³ of rare purity natural water is reproduced in the lake annually.

According to the UN, at the beginning of the 2000s, more than 1.2 billion people live in conditions of constant fresh water shortage, and about 2 billion suffer from it regularly. By the middle of the 21st century, the number of people living with constant water shortages will exceed 4 billion people. In such a situation, some experts say that Russia’s main advantage in the long term is water resources.

Fresh water reserves: atmospheric vapor - 14,000 or 0.06%, river fresh water - 200 or 0.005%, total Total 28,253,200 or 100%. Sources - Wikipedia: , .

List of countries by water resources[Source - 1]

Until relatively recently, water, like air, was considered one of the free gifts of nature, only in areas of artificial irrigation it always had a high price. IN Lately attitudes towards land water resources have changed.

Over the last century, the world's consumption of fresh water has doubled, and the planet's water resources cannot meet such a rapid increase in human needs. According to the World Commission on Water, today every person needs 40 (20 to 50) liters of water daily for drinking, cooking and personal hygiene. However, about a billion people in 28 countries do not have access to this amount of life-saving important resources. More than 40% of the world's population (about 2.5 billion people) lives in areas experiencing moderate or severe water stress. This number is expected to rise to 5.5 billion by 2025, accounting for two-thirds of the world's population. The overwhelming majority of fresh water is, as it were, conserved in the glaciers of Antarctica, Greenland, in the ice of the Arctic, in mountain glaciers and forms a kind of “emergency reserve” that is not yet available for use. Different countries differ greatly in fresh water reserves. Below is a ranking of countries with the largest freshwater resources in the world. However, this ranking is based on absolute indicators and does not coincide with per capita indicators.

10. Myanmar

1080 km3 Per capita

23.3 thousand m3 The rivers of Myanmar - Burma are subject to the monsoon climate of the country. They originate in the mountains, but are fed not by glaciers, but by precipitation. More than 80% of the annual river nutrition comes from rain. In winter, rivers become shallow and some of them, especially in central Burma, dry up. There are few lakes in Myanmar; the largest of them is the tectonic Lake Indoji in the north of the country with an area of ​​210 square meters. km. Despite fairly high absolute indicators, residents of some areas of Myanmar suffer from a lack of fresh water.

9. Venezuela

1320 km3 Per capita

60.3 thousand m3 Almost half of Venezuela’s thousand-plus rivers flow from the Andes and the Guiana Plateau into the Orinoco, the third largest river in Latin America. Its basin covers an area of ​​about 1 million square meters. km. The Orinoco drainage basin covers approximately four-fifths of Venezuela's territory.

2085 km3 Per capita

India has 2.2 thousand m3 a large number of water resources: rivers, glaciers, seas and oceans. The most significant rivers are: Ganges, Indus, Brahmaputra, Godavari, Krishna, Narbada, Mahanadi, Kaveri. Many of them have important as sources of irrigation. Eternal snow and glaciers in India cover about 40 thousand km2 of territory. However, given the huge population in India, the availability of fresh water per capita is quite low.

7. Bangladesh

2360 km3 Per capita

19.6 thousand m3 Bangladesh is one of the countries in the world with the highest population density. This is largely due to the extraordinary fertility of the Ganges River delta and regular floods caused by monsoon rains. However, overpopulation and poverty have become the real problem of Bangladesh. There are many rivers flowing through Bangladesh, and large rivers can flood for weeks. Bangladesh has 58 transboundary rivers and issues arising in the use of water resources are very sensitive in discussions with India. However, despite the relatively high level water supply, the country faces a problem: Bangladesh's water resources are often poisoned by arsenic due to its high levels in the soil. Up to 77 million people are exposed to arsenic poisoning through drinking contaminated water.

2480 km3 Per capita

2.4 thousand m3 The United States occupies a huge territory on which there are many rivers and lakes. However, despite the fact that the United States has such fresh water resources, this does not save California from the worst drought in history. In addition, given the high population of the country, the availability of fresh water per capita is not that high.

5. Indonesia

2530 km3 Per capita

12.2 thousand m3 The special topography of the territories of Indonesia, combined with a favorable climate, at one time contributed to the formation of a dense river network in these lands. In Indonesian territories all year round Quite a large amount of precipitation falls, because of this the rivers are always full and play a significant role in the irrigation system. Almost all of them flow from the Maoke Mountains north into the Pacific Ocean.

2800 km3 Per capita

2.3 thousand m3 China has 5-6% of the world's water reserves. But China is the most densely populated country in the world, and water on its territory is distributed extremely unevenly. The south of the country has fought and is still fighting floods for thousands of years, building and building dams to save crops and people’s lives. The north of the country and central regions are suffering from water shortages.

2900 km3 Per capita

98.5 thousand m3 Canada has 7% of the world's renewable fresh water resources and less than 1% of total number population of the Earth. Accordingly, per capita income in Canada is one of the highest in the world. Most of Canada's rivers belong to the Atlantic and North basins. Arctic Oceans, significantly fewer rivers flow into the Pacific Ocean. Canada is one of the richest countries in the world with lakes. On the border with the United States are the Great Lakes (Superior, Huron, Erie, Ontario), connected by small rivers into a huge basin with an area of ​​more than 240 thousand square meters. km. Less significant lakes lie on the territory of the Canadian Shield (Great Bear, Great Slave, Athabasca, Winnipeg, Winnipegosis), etc.

4500 km3 Per capita

30.5 thousand m3 In terms of reserves, Russia accounts for more than 20% of the world's fresh water resources (excluding glaciers and groundwater). When calculating the volume of fresh water, one resident of Russia accounts for about 30 thousand m3 of river flow per year. Russia is washed by the waters of 12 seas belonging to three oceans, as well as the inland Caspian Sea. On the territory of Russia there are over 2.5 million large and small rivers, more than 2 million lakes, hundreds of thousands of swamps and other water resources.

1. Brazil

6950 km3 Per capita

43.0 thousand m3 Brazil's water resources are represented a huge amount rivers, the main of which is the Amazon ( greatest river worldwide). Almost a third of this big country occupies the Amazon River basin, which includes the Amazon itself and more than two hundred of its tributaries. This gigantic system contains one fifth of all the world's river waters. The rivers and their tributaries flow slowly, often overflowing their banks during the rainy seasons and flooding vast areas of tropical forests. The rivers of the Brazilian Plateau have significant hydroelectric potential. The most large lakes countries - Mirim and Patos. Main rivers: Amazon, Madeira, Rio Negro, Parana, Sao Francisco.

Until relatively recently, water, like air, was considered one of the free gifts of nature, only in areas of artificial irrigation it always had a high price. Recently, attitudes towards land water resources have changed.

Over the last century, the world's consumption of fresh water has doubled, and the planet's water resources cannot meet such a rapid increase in human needs. According to the World Commission on Water, today every person needs 40 (20 to 50) liters of water daily for drinking, cooking and personal hygiene.

However, about a billion people in 28 countries around the world do not have access to as many vital resources. More than 40% of the world's population (about 2.5 billion people) lives in areas experiencing moderate or severe water stress.

This number is expected to rise to 5.5 billion by 2025, accounting for two-thirds of the world's population.

The overwhelming majority of fresh water is, as it were, conserved in the glaciers of Antarctica, Greenland, in the ice of the Arctic, in mountain glaciers and forms a kind of “emergency reserve” that is not yet available for use.

Different countries differ greatly in their freshwater reserves. Below is a ranking of countries with the largest freshwater resources in the world. However, this ranking is based on absolute indicators and does not coincide with per capita indicators.

10. Myanmar

Resources – 1080 cubic meters. km

Per capita- 23.3 thousand cubic meters. m

The rivers of Myanmar - Burma are subject to the country's monsoon climate. They originate in the mountains, but are fed not by glaciers, but by precipitation.

More than 80% of the annual river nutrition comes from rain. In winter, rivers become shallow and some of them, especially in central Burma, dry up.

There are few lakes in Myanmar; the largest of them is the tectonic Lake Indoji in the north of the country with an area of ​​210 square meters. km.

Despite fairly high absolute indicators, residents of some areas of Myanmar suffer from a lack of fresh water.

Resources – 1320 cubic meters. km

Per capita– 60.3 thousand cubic meters. m

Nearly half of Venezuela's thousand-plus rivers flow from the Andes and Guiana Plateau into the Orinoco, Latin America's third largest river. Its basin covers an area of ​​about 1 million square meters. km. The Orinoco drainage basin covers approximately four-fifths of Venezuela's territory.

Resources– 2085 cubic meters km

Per capita - 2.2 thousand cubic meters m

India has a large number of water resources: rivers, glaciers, seas and oceans. The most significant rivers are: Ganges, Indus, Brahmaputra, Godavari, Krishna, Narbada, Mahanadi, Kaveri. Many of them are important as sources of irrigation.

Eternal snow and glaciers in India cover about 40 thousand square meters. km of territory.

However, given the huge population in India, the availability of fresh water per capita is quite low.

Resources – 2360 cubic meters. km

Per capita– 19.6 thousand cubic meters. m

Bangladesh is one of the countries with the highest population density in the world. This is largely due to the extraordinary fertility of the Ganges River delta and regular floods caused by monsoon rains. However, overpopulation and poverty have become the real problem of Bangladesh.

There are many rivers flowing through Bangladesh, and large rivers can flood for weeks. Bangladesh has 58 transboundary rivers and issues arising in the use of water resources are very sensitive in discussions with India.

However, despite the relatively high level of water resource availability, the country faces a problem: Bangladesh's water resources are often subject to arsenic poisoning due to its high levels in the soil. Up to 77 million people are exposed to arsenic poisoning through drinking contaminated water.

Resources – 2480 cubic meters. km

Per capita– 2.4 thousand cubic meters m

The United States occupies a vast territory with many rivers and lakes.

However, despite the fact that the United States has such fresh water resources, this does not save California from the worst drought in history.

In addition, given the high population of the country, the availability of fresh water per capita is not that high.

Resources – 2530 cubic meters. km

Per capita– 12.2 thousand cubic meters. m

The special topography of the territories of Indonesia, combined with a favorable climate, at one time contributed to the formation of a dense river network in these lands.

In the territories of Indonesia, quite a large amount of precipitation falls all year round, because of this the rivers are always full and play a significant role in the irrigation system.

Almost all of them flow from the Maoke Mountains north into the Pacific Ocean.

Resources – 2800 cubic meters. km

Per capita– 2.3 thousand cubic meters. m

China has 5-6% of the world's water reserves. But China is the most populous country in the world, and water on its territory is distributed extremely unevenly.

The south of the country has fought and is still fighting floods for thousands of years, building and building dams to save crops and people’s lives.

The north of the country and central regions are suffering from water shortages.

3. Canada

Resources – 2900 cubic meters. km

Per capita– 98.5 thousand cubic meters. m

Canada has 7% of the world's renewable freshwater resources and less than 1% of the world's total population. Accordingly, per capita security in Canada is one of the highest in the world.

Most of Canada's rivers belong to the Atlantic and Arctic oceans; significantly fewer rivers flow into the Pacific Ocean.

Canada is one of the richest countries in the world with lakes. On the border with the United States are the Great Lakes (Superior, Huron, Erie, Ontario), connected by small rivers into a huge basin with an area of ​​more than 240 thousand square meters. km.

Less significant lakes lie on the territory of the Canadian Shield (Great Bear, Great Slave, Athabasca, Winnipeg, Winnipegosis), etc.

Resources– 4500 cubic meters km

Per capita – 30.5 thousand cubic meters. m

In terms of reserves, Russia accounts for more than 20% of the world's freshwater resources (excluding glaciers and groundwater). When calculating the volume of fresh water per resident of Russia, there is about 30 thousand cubic meters. m of river flow per year.

Russia is washed by the waters of 12 seas belonging to three oceans, as well as the inland Caspian Sea. On the territory of Russia there are over 2.5 million large and small rivers, more than 2 million lakes, hundreds of thousands of swamps and other water resources.

Resources – 6950 cubic meters. km

Per capita- 43.0 thousand cubic meters m

Brazil's water resources are represented by a huge number of rivers, the main of which is the Amazon (the largest river in the whole world).

Almost a third of this large country is occupied by the Amazon River basin, which includes the Amazon itself and more than two hundred of its tributaries.

This gigantic system contains one fifth of all the world's river waters.

The rivers and their tributaries flow slowly, often overflowing their banks during the rainy seasons and flooding vast areas of tropical forests.

The rivers of the Brazilian Plateau have significant hydroelectric potential. The largest lakes in the country are Mirim and Patos. Main rivers: Amazon, Madeira, Rio Negro, Parana, Sao Francisco.

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Being a native of Uzbekistan and having lived there for 41 years, apparently, I have a reverent attitude towards fresh water.