The father of African rivers, located in the northeast of Africa, is an international river. The Nile originates from the East African Plateau, Burundi Plateau, south of the equator. Its main stream flows through Burundi, Rwanda, Tanzania, Uganda, Sudan and Egypt, and finally flows into the Mediterranean Sea. With a total length of 6,670 kilometers, the main stream is the longest river in the world from the source of the Kagala River to the estuary. The tributaries also flow through Kenya, Ethiopia, parts of the Democratic Republic of the Congo, Eritrea and other countries. The basin covers an area of about 2.87 million square kilometers, accounting for more than one ninth of the African continent. The average annual runoff of the estuary is 8 1 100 million m3.
The word "Nile" first appeared more than 2000 years ago. There are two theories about its origin: one comes from the Latin "Nile", which means "impossible". Because the middle and lower reaches of the Nile have been inhabited for a long time, but because of the barrier of waterfalls, people in the middle and lower reaches think that they can't understand the source of this river, so they named it the Nile. The second is that the word "nilus" evolved from the name of the ancient Egyptian Pharaoh (king) Nyroos.
The Nile is formed by the confluence of three rivers: kagera river, White Nile and Blue Nile. The valley delta in the lower Nile is one of the earliest cradles of human civilization, where ancient Egypt was born. Up to now, 96% of Egypt's population and most of its agricultural production are concentrated here. Therefore, the Nile is regarded as the lifeline of Egypt. For thousands of years, the Nile River has flooded regularly from June to 10 every year. When the river reached its highest level in August, it flooded large fields on both sides of the river bank, and then people moved to high places to stay temporarily. After 10, the flood subsided, bringing fertile soil to the Nile. On these fertile land, people planted cotton, wheat, rice and jujube crops. A "green corridor" has been formed in the arid desert area. Egypt, an ancient civilization with a history of 5,000 years, has created splendid Egyptian culture here. Today, more than 90% of Egypt's population is distributed in the plains and deltas along the Nile. Egyptians call the Nile the mother of their lives.
The upper reaches of the Mueller River in Soltani are 1730km long, which are called kagera river, Victoria Nile and Albert Nile respectively from top to bottom. From Nimulai to Khartoum, the middle reaches of the Nile River are 65,438+930 km long, which is called the White Nile, among which Malakal is also called the Jebel River, and the largest tributary, the Blue Nile (B65,438+0 UC Nile), flows into the lower reaches of Khartoum. The White Nile meets the Blue Nile, which is called the Nile and belongs to the lower reaches, with a length of about 3000km. The Nile River crosses the Sahara desert and enters the estuary delta north of Cairo, where it divides into two tributaries and flows into the Mediterranean Sea.
The Nile, the mother of Egypt
The Nile River originates from the south of the equator, and on the plateau in eastern Africa, it meanders and flows from south to north. The Nile runs through northeast Africa, flows through Tanzania, Rwanda, Burundi, Uganda, Ethiopia, Sudan and Egypt, and finally flows into the Mediterranean Sea. With a total length of 6,740 kilometers, it is the longest river in Africa and the longest river in the world, with a drainage area of 2.8 million square kilometers, equivalent to110 on the African continent.
There are two sources of the Nile, one of which originated in the mountainous area of tropical Central Africa at 262 1 m, and is called the White Nile. The White Nile flows through huge lakes such as Lake Victoria and Lake Keoga, passes through the jungles of Uganda, and goes north via Sudan. Another source of the Nile is the Ethiopian plateau at an altitude of 2000 meters. It's called the Blue Nile. The Blue Nile is 680 kilometers long. It passes through Lake Tana, and then turns sharply, forming a current. This is the second largest waterfall in Africa-Tissett Falls. The roaring Blue Nile rushes into the Sudan Plain and meets the calm White Nile, which is the Nile we are familiar with.
As early as more than 6000 years ago, the ancestors of the Egyptians thrived on both sides of the Nile. There is an Egyptian proverb, such as "Egypt is the Nile, and the Nile is the mother of Egypt". The Nile is indeed the source of life for the Egyptian people. It accumulated a lot of wealth for the coastal people and created the ancient Egyptian civilization. There are more than 70 pyramids, large and small, along the Nile River, just like a voluminous "history book", which contains the mystery of human civilization. More than 6,700 kilometers of the Nile created pyramids, created ancient Egypt, and created a miracle of mankind.
The Nile runs through the northeast of the African continent, flows through Burundi, Rwanda, Tanzania, Uganda, Ethiopia, Sudan and Egypt, crosses the largest Sahara desert in the world, and finally empties into the Mediterranean Sea. The basin covers an area of about 3.35 million square kilometers, accounting for one ninth of the African continent, with a total length of 6,650 kilometers and an average annual flow of 3 100 cubic meters per second, making it the longest river in the world. Nile-Arabic means "big river". "Nile, Nile, longer than Tianhe" is a proverb that Sudanese people praise the Nile.
There is a long section of the Nile flowing through the desert, where the river water is only lost and not replenished. Because the upstream source of the river is a tropical and rainy area, where the flow is huge, although a large amount of runoff is lost along the desert due to evaporation and leakage, the Nile can still maintain a long-flowing river. A river like the Nile, which is not formed by local runoff but simply flows through, is called a guest river. The local climatic conditions have no positive influence on the formation of these "guest rivers", only negative influence.
Near the intersection of latitude and longitude on the left is Cairo.
The lowest Nile divides into many tributaries, which flow into the Mediterranean, and all tributaries flow on the delta plain. The delta covers an area of about 24,000 square kilometers with flat terrain and criss-crossing rivers and canals. It is the cradle of ancient Egyptian culture and the political, economic and cultural center of modern Egypt.
The Nile River near Dandara, Egypt
The upper reaches of the Nile River are kagera river, which originates from Burundi in the East African Plateau and flows into Lake Victoria in the lower reaches. The lake flows into Lake Keoha through Owen Falls, which is called Victoria Nile after leaving the lake, and then flows into Lake Abbott through Kabarega Falls. The lake flows from the northern end and is called Abbott Nile. Since Nimule, it has been named White Nile. The White Nile flows northward along the slope of the East African Plateau. The valley is deep and narrow with many steep beaches and waterfalls. From Bor to the north, the White Nile flows into the shallow swamp basin, with slow flow, and a large number of aquatic plants mainly papyrus grow in the river. After flowing out of the basin, the White Nile flows northward, and successively joins the Sobat River, the Blue Nile River and the atbara river, with no tributaries below. The banks of the White Nile are flat, with bedrock occasionally exposed. The intersection of the White Nile and the Blue Nile is surrounded by the Gizla Plain. The river below the confluence is called the Nile. The Nile flows through the sedimentary rock area north of Khartoum. This valley is a shallow canyon with a flat bottom. The valley near Wadi Halfa is only 20 1 m wide, so the valley from here to Aswan is very narrow. Below Aswan, the valley widens and extends to about 16km at Naja hammadi. The river is close to the east coast, and the valley plains are mostly in Hexi. There are six waterfalls between Kasimu and Aswan, which are all caused by the basement crystalline rocks that form the plateau on the east side of the valley and extend westward into the valley. The valley walls on both sides are asymmetrical, with the east wall high and steep and the west wall low and gentle.
The White Nile originated in the rainy equatorial region, with abundant and stable water. However, after flowing out of the plateau into the basin, because the terrain is extremely flat and the water flow is extremely slow, the plants in the water also delay the progress of the water flow. In the dry areas at low latitudes, it evaporates strongly under the irradiation of sunlight, thus wasting a huge amount of water, and very little water can flow downstream. The annual average flow at the junction of the White Nile and the Blue Nile is 890 cubic meters per second, which is about half of that of the Blue Nile. The water in the lower Nile mainly comes from Sobat River, Blue Nile and atbara river, among which Blue Nile is the most important. Sobat River, a tributary of the White Nile, began to rise in May, and the highest water level appeared in June 5438+065438+ 10. At this time, the water level of Sobat River is higher than that of White Nile, which helps the latter to flow backward, thus enhancing the evaporation of water in the upper reaches of White Nile. The Blue Nile originates from Lake Tana in the Ethiopian Plateau, and its upper reaches are located in rainy areas in tropical mountainous areas, where it is rich in water resources. Due to the strong seasonal precipitation, the river flow changes greatly during the year. The amount of water in spring is limited, and it began to rise in June, and then rose rapidly and continuously, reaching a peak in early September. In the meantime, it will also make the White Nile flow backwards. The water level dropped from June 1 1 to February 1, followed by the dry season. The minimum flow in dry season is less than 100 cubic meter per second, which is about one sixtieth of the maximum flow in flood season. Atbara river also originated in the Ethiopian Plateau. Because it is located in the north, the rainfall is concentrated, and its drainage area is small, so the flow changes greatly. In winter, the river bed becomes a series of small lakes.
The flood in the main stream of the Nile reached Khartoum in June and reached its highest level in September. The maximum flood peak appeared in Cairo in June+10, 5438. 60% of the total water of the Nile comes from the Blue Nile, 32% from the White Nile and 8% from atbara river. During the flood, Blue Nile accounted for 68%, atbara river accounted for 22%, and White Nile accounted for 10%. In dry season, the White Nile accounts for 83%, and the Blue Nile accounts for 17%.
The Nile Valley is divided into seven regions: East African Lake Plateau, Mountain River Region, White Nile Region, Blue Nile Region, atbara river Region, Nile Region North of Khartoum and Nile Delta. 1862 On July 28th, British explorer John Henning speke discovered the "source" of the Nile in Lake Victoria. At that time, it was calculated that the total length of the river was 5588 kilometers. Later, it was found that the farthest source was the birthplace of kagera river in the East African Lake area. The North River flows into Lake Victoria, the largest lake in Africa, from the west through Tanzania, Rwanda and Uganda. The main stream of the Nile originates from this lake, which is called Victoria Nile. The river passes through Lake Keoga and Lake Albert, and it is called Albert Nile after flowing out. When it flows into the Sobat River, it is called the White Nile. Another Blue Nile, which originated in the highlands of central Ethiopia, joins the White Nile in Khartoum, Sudan, and then receives the last major tributary, atbara river, north of Dammeyer, and is called the Nile. From here, the Nile flows in an S-shape around the Nile landscape in Aswin to the northwest, and flows into Nasser Reservoir after passing through three waterfalls. After leaving the reservoir and entering the Nile Delta via the Egyptian capital, the river divides into several tributaries and finally flows into the eastern end of the Mediterranean.
On the left is the satellite image of the Nile. The green sector on the upper left is the Nile Delta, the long dark blue part in the middle is the Red Sea, and the winding line on the left side of the Red Sea is the Nile. There is an irregular wide section in the middle and upper part of the river in the picture, which is Nasser Reservoir, where the famous Aswan Dam is located.
The Nile is characterized by frequent flooding. In northern Sudan, it usually starts to rise in May and reaches the highest level in August. After that, the water level gradually decreased, and the water level was lower from 1 to May. Although floods occur regularly, the amount of water and the time of high tide vary greatly. The reason for this phenomenon is the Blue Nile and atbara river, whose water source comes from seasonal rainstorm on Ethiopian plateau. More than 80% of the Nile's water is provided by the Ethiopian plateau, and the rest comes from the lakes in the East African plateau. When the flood comes, it will flood the farmland on both sides, and when the flood recedes, it will leave a thick layer of river mud and form fertile soil. Four or five thousand years ago, Egyptians knew how to master the flood law and make use of the fertile land on both sides of the strait. For a long time, the Nile valley is full of cotton fields and fragrant rice flowers. Between the Sahara desert and the Arabian desert, the winding Nile is like a green corridor, full of infinite vitality.
This is a set of satellite images of the Nile before and after the flood season. April and August 2000 and May and August 20001year. This picture clearly shows that the river widened during the flood season.
Also translated as Amazon River; Spanish is Rio Amazon.
The largest river in South America, with the largest flow and the widest basin in the world. It is about 6,400 kilometers (4,000 miles) from the birthplace of the Kaiali-Apurimac river system in Peru, which is slightly shorter than the Nile. Its westernmost source is the towering Andes less than 160 km (100 mile) from the Pacific Ocean, and its mouth is in the Atlantic Ocean.
Amazon River is located in the north of South America, with the widest drainage area and the largest flow in the world. Originating from the eastern slope of Cordillera in the Andes of Peru, there are two sources: one is the Maranon River, which is usually regarded as the positive source of the Amazon River, and it originated in the high mountain area of the Andes of Peru; The other is the Ukaj-Ali River, whose source is called the Appuhn Mark River. After crossing the towering mountains, the maranhao River and the Wu Kaiali River meet near Nota, Peru. The main tributary of the Amazon River winds through seven countries in South America. The Amazon River from Iquitos, Peru to Manaus, Brazil is called Solimos River, and the section from the mouth of the Negro River to the Atlantic Ocean is called Amazon River. The Amazon River flows eastward through northern Brazil and empties into the Atlantic Ocean near Marajo Island.
The vast Amazon river basin is the largest lowland in Latin America, with an area of about 6 million square kilometers (2.3 million square miles), almost twice that of any other major river basin in the world. The widest point of the Amazon river basin is about 2776 kilometers (1725 miles) from north to south. Including most of Brazil and Peru, parts of Colombia, Ecuador and Bolivia, and a small part of Venezuela, about two-thirds of the main stream and most of the river basins are in Brazil. It is estimated that the flow of the Amazon River accounts for 65,438+0/5 of the total flow of the earth's surface, and the average flow of the estuary is about 65,438+075,000 cubic meters per second (6,654,38+080,000 cubic feet per second), which is more than 65,438+00 times that of the Mississippi River. A large amount of fresh water makes it as far away as possible.
Central and northern Andes and Amazon basin
The Amazon basin is not an infinite swamp. Although a large area of lowlands is flooded every year, most of the land is hilly "terra firme", which far exceeds the flood level. There is a vast tropical rain forest in the basin, which is the largest treasure house of biological resources in the world.
The first European to explore the Amazon was Spanish soldier orellana. It is said that when he reported a fierce battle with tribal women warriors, he compared them to the Amazon in Greek mythology, so he named the river Amazon. Although Amazon is used to referring to the whole river, according to the nomenclature of Peru and Brazil, it is only applicable to some river sections. In Peru, the upstream of the main stream flowing to Iquitos is called the Maranon River, and the one flowing from Iquitos to the Atlantic Ocean is called the Amazon River. In Brazil, from Iquitos to the mouth of the Negro River is called Solimos River, and from the Negro River to the mouth is called Amazon River.
Amazon boa constrictor, Brazil, in the northern part of the Amazon River basin.
The source of the Madeira River in southern Bolivia (about 20 south latitude), the source of the Poyut River in Cuenca, Ecuador (79° 3L west longitude) in the west, and the Bay of Marajo in Brazil (about 48 west longitude) in the east. The whole basin spans 25 latitude and longitude is 3130'. If the source of the Amazon River is the maranhao River, its total length is 6299km, and if the source is the Kaiali River, its total length is 6436km, ranking second in the world after the Nile. The average annual discharge of the estuary is 65,438+750,000 m3/s, the average annual runoff is 6,930 billion m3, the average annual runoff depth is 1200mm, the suspended sediment concentration is 0.22kg/m3, and the sediment discharge is 900 million t. In wet years, the river near Manaus in the middle reaches is 5km wide, the downstream is 20km wide and the estuary is 80km wide. The estuary is trumpet-shaped and 240 kilometers wide. The average water depth of the downstream channel is 20-50m, the maximum water depth is 100m, and the annual variation of water level is 9m. The annual average flow of Iquitos in the upper reaches is 20420-28200m3/s, and the average ratio of the Amazon River drops to 0.035m/km from Iquitos to Haikou.
The Amazon River is the second longest river in the world (about 6,400 kilometers) after the Nile. In northern South America. It is estimated that about 20-25% of all water flowing on the earth's surface is in the Amazon River. The estuary is 240 kilometers wide, and the flow in flood season reaches 654.38+0.8 million cubic meters per second, which is 654.38+00 times that of Mississippi River. The displacement is so large that the sea water becomes weak within the range of 160 km from the shore. There are more than 1000 known tributaries, of which 7 tributaries are more than 1600 km long. 20 of them exceed 1000 km.
It is formed by the confluence of Kaiali River and Maranyon River, which originated in the Andes of Peru, and flows eastward through northern Brazil to the Atlantic Ocean near Marajo Island. The total length is 6437 kilometers (from the source of the Kaiali River). There are more than 20 tributaries whose length exceeds 1000 km. The basin covers an area of 6.22 million square kilometers, accounting for about 35% of the South American continent, including most or part of the territories of Brazil, Bolivia, Peru, Colombia, Ecuador, Venezuela and other countries. Most areas in the basin belong to tropical rain forest climate, with annual rainfall exceeding 2,000 mm and abundant water all the year round. The average annual discharge of the estuary is 220,000 m2/s, and the flood season discharge exceeds 280,000 m2/s. It is the largest river with the widest basin area in the world. In Shangyuan area, the mountains are high and the valleys are deep, the slopes are steep and the water flows rapidly, with an average gradient of about 5.2‰. After entering the plain, the slope is small. The average velocity in the middle and lower reaches is 0.7-1.7m/s. The depth of this river is very wide. Most rivers in Brazil are more than 45 meters deep, and the water depth near Manaus is 99 meters. The lower reaches of the river are 20-80 kilometers wide, the estuary is trumpet-shaped and 240 kilometers wide, and shoal sandbars are listed. Tides can rush to Obidos, 960 kilometers above the estuary. More than 5,000 kilometers of the main stream can be navigable all the year round, and ships with a draft of 5-6 meters can travel back 3,700 kilometers from the estuary to Iquitos, Peru; The navigable river length of the whole water system is 30,000 kilometers (normal water level). Hydraulic resources are also quite rich, but they have not been fully developed.
The fertile silt deposited in the Amazon River nourishes an area of 65,000 square kilometers, and its basin area is about 7.05 million square kilometers, almost twice that of any other big river basin in the world. The famous Amazon rainforest grows in the Amazon River basin. It is also the largest plain in the world (covering an area of 5.6 million square kilometers). The plain is low and flat, mostly below150m above sea level, so there are many rivers and lakes here. Rainy, humid and continuous high temperature are its remarkable climatic characteristics. There are the richest and most diverse biological resources in the world, with millions of species.
The Amazon River is the largest river in South America and the largest river in the world. The Amazon River rises in the Andes in southern Peru and flows eastward. Along the way, it received 1000 tributaries, with a total length of 6,400 kilometers, and finally merged into the Atlantic Ocean. The Amazon river basin covers an area of 7.05 million square kilometers, accounting for about 40% of the total area of South America. The amount of water injected into the Atlantic Ocean every year is about 6,600 cubic kilometers, which is equivalent to 1/6 of the total amount of water injected into the ocean by rivers in the world.
The upper reaches of the Amazon River are about 2,500 kilometers long and divided into upper and lower sections. The upper section is about 1000 km, with a drop of 5000 meters. The mountains are high and deep, and the slopes are steep and flowing rapidly, forming a series of rapids and waterfalls. Downstream, two huge tributaries flow into the section between the two estuaries of the Amazon River. Because they enter the Amazon plain, the flow rate is slow and the meander is developed, and the end river is about 2000 meters wide.
The middle reaches of the Amazon River flow through Peru, Colombia and Brazil, with a total length of about 2,200 kilometers. In northern Brazil, the Amazon River is 45 meters deep and 3000 meters wide, and its flow rate is slow. Islands and continents crisscross in the river, and rivers are distributed in a network. The floodplain on both sides of the river is 30 ~ 100 km wide, with low terrain, dense lakeside and poor drainage. On both sides of the river, there are many shipping tributaries on the Amazon River near Gurupa, Pará, Brazil, all of which originate from the eastern slope of the Andes and are distributed in a feather shape. At the end of the middle reaches, the river channel is 1 1km wide and 99m deep.
The downstream reaches 1600 km, sometimes the water depth is wide, the terraces on both banks are clear, the terrain is low and flat, and the floodplain is dotted with lakes, sometimes the water surface is tight and the water flow is accelerated. The mouth of the sea is 330 kilometers wide, and the tides in the Atlantic Ocean can go up downstream, reaching as far as 1600 kilometers. The Amazon river system spans the north and south of the equator. It is hot and rainy all the year round, and it is rich in species, with more than 2,000 kinds of freshwater fish. There are also manatees, freshwater dolphins, crocodiles, giant water snakes and other aquatic animals. Most areas in the basin are covered with dense tropical rain forests, with a wide variety of plants and rich mineral resources.
However, the Amazon River is the most famous freshwater ornamental fish producing area in the world. Its rich and beautiful freshwater tropical ornamental fish have always touched the hearts of ornamental fish lovers and biologists all over the world.
The Amazon River is the pride of Latin American people. Flowing through Peru, Brazil, Bolivia, Ecuador, Colombia, Venezuela and other countries, it nourishes 8 million square kilometers of vast land and breeds the world's largest tropical rain forest, making the Amazon River basin the most mysterious "kingdom of life" in the world.
The Amazon River is more than 6,000 kilometers long and has thousands of tributaries. Together with the main stream, it forms an Amazon river network with a total length of more than 60,000 kilometers, with a basin area of about 8 million square kilometers, most of which are in Brazil.
Due to the rain near the equator, the Amazon water is abundant all the year round. The annual average flow of the mouth of the Amazon River is 220,000 cubic meters per second, which is the widest and largest river in the world. Brazilians proudly call it "river and sea". The height difference between the source of the Amazon River and the estuary is not big, and it is located in the equatorial rainy area. The river bed is deep, wide and flat, and the flow rate is very slow, which is suitable for shipping. Manaus Port is an important port of Amazon River.
There is also a natural wonder of the Amazon River-tidal bore, which can be compared with the tidal bore of Qiantang River in China. After crossing the vast South American continent, Amazon flows into the Atlantic Ocean near Marajo Island in Brazil. The mouth of the Amazon River is a huge trumpet. After the tide enters this trumpet mouth, it is continuously squeezed and lifted into a wall-standing tidal head, which can be traced back to 600 ~ 1000 km. Generally, the height of tidal head is1~ 2m, and it can reach 5m at high tide.
Brazilians call the Amazon tide "Bobo Roca", and tourists rush to go at high tide. Every high tide, the sound of the waves is deafening, and the sound travels for miles and is magnificent.
The Amazon River, with a total length of 6,440 kilometers, ranks second among the rivers in the world, second only to the Nile River, which is 6,695 kilometers long. The Amazon River injects 65,438+065,438+06,000 cubic meters of water into the Atlantic Ocean every second, which is about three times more than the Pisa River, ten times more than the Mississippi River and sixty times more than the Nile River, accounting for one-fifth of the total flow of rivers into the sea in the world. Abundant water and surging water power rushed into the Atlantic Ocean 160 km from the fresh water in the estuary. Among the tributaries, seven are longer than 1600 km; The longest is the Madeira River, which is more than 3,200 kilometers long.
The Amazon basin has the largest number of plant species in the world. Many trees are more than 60 meters high, covering the sky, so the ground of dry land forest is bare, with only a layer of rotten branches and leaves. The situation of waterlogged forests is completely different. Shrubs and trees have plate-like roots to help them survive. The crown is layered from high to low, and each layer is full of vitality. Pueraria lobata, orchids and bromeliads scrambled to cling to the high branches, where monkeys, sloths, hummingbirds, macaws, butterflies and countless bats lived.
In the Amazon River, caiman, freshwater turtle, manatee, freshwater dolphin and other aquatic mammals live. Jaguars, slender-waisted cats, tapirs, tapirs, capybara and armadillos live on land. There are more than 2,500 species of fish and 1600 species of birds. The Amazon python is the largest snake in the world today. It can reach ten meters in length and weigh more than 225 kilograms, which is as thick as the trunk of an adult man. But generally speaking, the length of boa constrictors is less than five and a half meters. Pythons are naturally fond of water and usually inhabit mudflats or shallow waters, preying on waterfowl, turtles, capybara, tapirs and so on. Sometimes they even swallow the caiman, which is two and a half meters long. The boa constrictor will wrap the Cayman tightly until it suffocates, then swallow it whole, and then stop eating for several weeks. Although adult pythons are terrible carnivores, young pythons are only 760 mm long at birth. Small pythons are oviparous, sometimes up to 70 at a time. Many young snakes were eaten by caimans. When the survivors grew up, they took turns eating caiman.
Some Amazon rainforests have been turned into protected areas, such as the Amazon National Park on the banks of the Taparros River in West Asia, covering an area of nearly 10,000 square kilometers. However, if the current deforestation rate is not slowed down, Amazon, a vast forest that accounts for two-thirds of the global forest area, will disappear in 2 1 century.
It is almost as difficult to imagine the magnificence of the Amazon River as to understand infinity. The Amazon River has 15000 tributaries, which are distributed in a large area of South America, and the basin area is almost as large as that of Australia. The mainstream river is so deep that half of the whole river can accommodate a huge ship. Ocean-going ships can sail upstream from the Atlantic Ocean through the estuary to Iquitos, Peru. The navigable river is wide, so you can't see both sides at the same time.
This river spans South America and originates in the Andes of Peru. Water flows out of the lake where glaciers meet, surging and scouring a brick canyon on the eastern hillside. Because a lot of sediment rushed out, the river was turbid, like coffee with a lot of milk, so it was called Baishui River. There are also some tributaries that flow through the swamp and rush out of humus. The water is dark and black, called Heishui River. As the terrain becomes gentle, the river slows down and flows to the vast Amazon basin below the mountain.
Since the middle of19th century, brave adventurers have entered the tropical rain forest of South America with the help of the Amazon River and its numerous tributaries. But although scientific explorers have been drifting on these rivers for more than 100 years, the life contained in the Amazon River is still unknown to the world.
Some scientists began to explore the depth of the Amazon River. They cast nets on the river, hoping to know the situation in the water. With the catch, the Amazon River, the longest tropical river on earth, gradually unveiled its mystery. Scientists have seen creatures they have never seen before, including transparent catfish and electric fish that eat the same kind of tails.
John, a ichthyologist at the University of Arizona, USA? Dr. lundberg said: "We sailed about 4,000 kilometers on the Amazon River and its tributaries and found completely different fish." Richard, honorary professor of ichthyology at the University of Miami, USA? Dr Robbins thinks that lundberg's research work is groundbreaking. He persuaded the National Science Foundation to fund Dr. lundberg's fishing expedition in the Amazon River. Professor Robbins said that even if the rugged riverbed would make the expedition lose all its fishing nets, it would be worthwhile if it could successfully catch a net of fish. He said, "No one knows what this river looks like. This will be a major breakthrough. "
Just like the Amazon rainforest, the Amazon River is home to all kinds of life, which makes South America have more fish species than any continent in the world. It is estimated that up to now, there are at least 2,000 species of freshwater fish in the Amazon River and its tributaries, twice as many as those in the United States, Canada and Mexico combined. William, a ichthyologist at the University of Michigan Animal Museum? l？ Dr. Fink said: "There are many kinds of fish there, and how it all happened is an interesting question. Deep-water fish are very special, and it is very challenging to study them. You are entering a strange and interesting world. " So far, scientists in the United States and Brazil have caught 125000 fish, belonging to 240 species, and the species of fish are increasing. Scientists found that the Amazon River is a dark world, where two kinds of fish live: electric fish and catfish.
The Amazon river has a high mud content, and people's sight can only reach tens of centimeters underwater, and it is dark below 6 meters. Researchers say this can explain why two kinds of fish can live in the dark river bottom without light. Electric fish can swim around to catch food without vision. It relies on the electrical officer to generate an electric field around the body to judge the position and find prey. Catfish can also feel the current. In addition, their bodies are covered with taste buds, and they use other senses instead of vision. The most incredible thing that Dr. lundberg and his colleagues found about electric fish is that there are two kinds of electric fish in the Amazon River that eat the tails of other electric fish. When the researchers examined the fish, they saw that their bellies were stuffed with electric fish tails. Dr lundberg said that this kind of electric fish not only ate the tails of other kinds of electric fish, but also spared the tails of the same kind. Electric fish has the ability to quickly regenerate all parts of the body, so that its food source is fully guaranteed.