Longest Rivers in the world
- The Amazon River is the largest river in the world in terms of volume and water. A meander is a bend in a river. A youthful river is a river with a steep gradient that flows quickly and has very few tributaries. A mature river is a river with a less steep gradient and flows more slowly than youthful rivers. An old river is a river with a low gradient and low erosive energy. The Rhine River is one of the longest and most important rivers in Europe. The Ganges River is worshipped by Hindus as a goddess.
• The Yellow River is also called the “Mother of China.”
Rivers are large natural streams of water that flow into other water bodies. They are formed in watershed areas, which are bounded by hilltops or ridges. As rain falls and snow melts on the hillsides, the water runs downhill forming a river channel.
The size of a river depends on the amount of rainfall and snowfall in the watershed areas.
Rising from south of the equator in Uganda and winding through north-east Africa all the way to the Mediterranean Sea, it is not just Earth’s longest river (though some have contested it’s beaten by the Amazon), but indisputably one of the most historic and diverse.
Understandably considered to be the ‘father of African rivers the River Nile is quite simply awe-inspiring.
The Blue Nile begins at Lake Tana, Ethiopia, and is its secondary source, flowing into the White Nile near Khartoum.
The Nile is formed from three principal sources: the White Nile, Blue Nile and Atbara. The White Nile begins at Lake Victoria, Uganda, and is the most southerly source.
Lastly the Atbara River, which begins around 50 kilometres (30 miles) north of Lake Tana, is the third and smallest source, joining the other two bigger waterways at the eponymous Sudanese city of Atbara.
Combined, these three primary sources create the River Nile, which today is naturally split into seven distinct regions ranging from the Lake Plateau of eastern Africa down to the vast Nile Delta that spans north of Cairo.
These areas are home to diverse peoples and cultures, exotic flora and fauna, as well as a variety of notable features ranging from fi erce rapids, to towering waterfalls and lush swamps. While the Nile flows through many countries including Uganda, Sudan and Ethiopia, the country it is most affi liated with is Egypt, the most northerly and the last it passes on its course to the Mediterranean.
Also Read : Largest forest in south America
Most sources list the Amazon as 4,080 mi long (6,580 km), making it second to the NILE in length. However, there is some debate about the length of the Amazon versus Nile depending on the actual starting point of the source. According to recent discoveries, the Amazon is 4,195 miles (6,712 km) long if the course follows the Apurimac branch (rather than the Urubamba branch) of the Ucayali to a point 17,200 ft (5,242 m) above sea level, making it 50 mi (80 km) longer than the Nile.
The northern half of the South American continent is shaped like a shallow dish. More than 1,000 tribu- taries, seven of which are more than 1,000 mi (1,613 km) long, flow through nine South American countries (Brazil, BOLIVIA, PERU, ECUADOR, COLOMBIA, VENEZUELA, GUYANA, SURINAME, and FRENCH GUIANA) that con- tribute waters to this dish. Beyond the riverbanks there are broad, swampy floodplains covered with lush, pe- riodically flooded forests.
The Ucayali and Maranon rivers, both of which rise in the permanent snows and glaciers of the high Andes Mountains, flow along roughly par- allel courses to the north before joining near Iquitos, Peru. Beyond Iquitos the river turns abruptly eastward, flowing along a very gentle gradient (approximately 1.25 in or 3.2 cm per mile) more or less paralleling the equator as it meanders over lowland plains. At Man- aus, approximately 1,000 mi (1,610 km) upstream from the coast, the elevation is only 100 ft (30 m) higher than Belem, which is an ocean port.
THE RAINFOREST The Amazon
rainforest, also known as Amazonia, is the largest tropical rainforest in the world, covering more than half of Brazil. It is also one of the world’s greatest natural resources, containing the largest single reserve of biological organisms in the world.
No one really knows exactly how many different species in- habit the area, but scientists estimate there are between 800,000 and 5 million, amounting to 15 to 30 percent of all the species in the world. Because its vegetation continuously recycles carbon dioxide into oxygen, it is often referred to as the “Lungs of our Planet.” The Amazon Rainforest consists of four layers or communities.
They take advantage of the wind by developing winged seeds that are blown to other parts of the forest. Trunks can be up to 16 ft (4.9 m) around and braced by massive buttress roots. Some of the animals find everything they need to survive in the emergent layer and never leave it.
Each layer has unique ecosystems, plants, and animals adapted to that system. The emer- gent layer is the tallest layer, where trees can be as tall as 200 ft (61 m) and rise well above the canopy. Here they are exposed to fluctuation of temperature, wind, and rainfall. The leaves are small and covered with a thick waxy surface to hold water.
- The Yangtze Asia’s longest river, flowing across eastern China from the Tibetan Plateau to the East China Sea; China’s most commercially important river
Known in China as the Chang Jiang—“Long River”— the Yangtze is the longest river in Asia and the third longest in the world, after the Nile and the Amazon. From its glacier-fed source in the Tanggula Mountains on the Tibetan Plateau, to its mouth in the East China Sea, it flows 3,900 miles (6,300 km).
Since 2006, the river’s middle course has been regulated by the world’s largest hydroelectric dam, the Three Gorges Dam, which has created a reservoir 370 miles (600km) long.
The catchment area of the Yangtze covers one-fifth of the area of China and is home to one-third of the country’s population. Epic journey On its journey across eastern China, the Yangtze flows through steep valleys, towering gorges, lake-strewn plains, and farmland, before forming a delta, where the megacity of Shanghai lies.
The Grand Cana the longest human-made waterway on Earth at 1,100 miles (1,700km)—links the lower section of the Yangtze to the Yellow River and Beijing to the north.
GOLD DUST RIVER
In its upper course, the river passes through the mountainous Yunnan Province. Here the Yangtze is known as the Jinsha Jiang,
The Mississippi River’s source is Lake Itasca in northern Minnesota, which it leaves as a stream just 10 ft (3m) wide. The Mississippi’s western tributaries, including those of the Missouri, drain the Great Plains, while those to the east drain the Appalachian Plateau.
The Mississippi–Missouri river system is the largest watershed in North America, draining more than 40 percent of the contiguous U.S. (all of the country except for Alaska and Hawaii).
Great River In combination, the Mississippi–Missouri stretches 3,710 miles (5,970 km), making it the fourth longest river in the world after the Nile, Amazon, and Yangtze.
Also known as the Big Muddy, the silt- laden Missouri discharges into the clearer Mississippi just north of St Louis in Missouri.
However, it is only after its confluence with the Ohio River—the Mississippi’s largest tributary by volume—at Cairo, Illinois, that the river takes on the full grandeur that led Algonquian-speaking inhabitants to name it Misi-ziibi—“Great River.”
The Yellow River
The most silt-laden river on Earth, the Yellow River takes its name from its coloration by the fine, windblown sediment, known as loess, that it carries along its lower course.
It is the second longest river in China, after the Yangtze, and one of the longest in the world.
After rising high on the Tibetan Plateau, the Yellow River follows an arching route eastward across the northern plains of China to the Yellow Sea, a journey of 3,393 miles (5,460 km).
Cradle to grave Known as both China’s Mother River and the Cradle of Chinese Civilization, the Yellow River historically sustained one of the country’s most fertile and productive regions.
However, the river basin is extremely prone to flooding, and a series of devastating floods has also earned the river the names the Ungovernable and China’s Sorrow .
As a result, much of the lower course of the Yellow River has been ramparted by levees and many of its tributaries have been dammed to control its flow.
The Ob–Irtysh river
Freezing and floods Measuring a total of 3,460 miles (5,568 km) from the source of the Irtysh to the mouth of the Ob, the river system is the longest in Siberia. Its catchment area is similar in size to the huge Mississippi–Missouri basin .
system is a combination of two major Asian rivers that have their sources on different sides of the Altai Mountains and flow north, through the Siberian lowlands, to the Arctic Ocean.
The Ob–Irtysh empties through the Gulf of Ob, the world’s longest estuary.
In its lower reaches, the river becomes braided across a vast, swampy plain that is subject to seasonal freezing and floods.
The congo is the second longest river of Africa. It starts from the south-west of Lake Tanganyika and flows into the Atlantic Ocean. The Zaire basin is one of the wettest regions of the Earth and is covered with dense impenetrable jungle.
The river and its network of tributaries are not navigable because of rapids and waterfalls caused by the descent from the plateau to the coast.
- The Lena has one of the largest basins in the world, draining one-fifth of Russia’s territory.
One of the three great Siberian rivers, along with the Ob–Irtysh and Yenisei, the Lena flows 2,700 miles (4,400 km) from its source in the Baikal Mountains, just west of Lake Baikal (see pp.238–39), across Siberia to its mouth in the Laptev Sea (an arm of the Arctic Ocean).
In its lower reaches, it is free of ice for only 4–5 months each year, following seasonal flooding. At its mouth, the river forms the largest delta in the Arctic and the second largest on Earth. Spanning 170 miles (280 km) and pushing out 70 miles (120 km) into the ocean, it comprises lakes, channels, sandbars, and islands, with extensive peat bogs.
In winter, it is a harsh wilderness, but in spring it supports millions of migratory birds.
At its mouth, in the South China Sea, it forms a delta just south of Ho Chi Minh City. With a length of about 2,700 miles (4,350 km), the Mekong is the longest river in Southeast Asia.
Like the Yellow River and the Yangtze, the Mekong has its source on the Tibetan Plateau. It runs in a southeast direction through western China, Myanmar, Laos, Thailand, Cambodia, and Vietnam, crossing some national borders and forming others.
The very long river basin includes many climatic zones and a diverse range of habitats including upland plateaus, forests, savannas, grasslands, wetlands, and mangroves. As a result, it is an area of extremely high biodiversity.
The Niger River is the principal river of West Africa, extending about 4,180 km.
This river is the chief river of West Africa. It rises from the Fouta Djllon Mountain quite close to the sea but flows north and then turns south again to form a wide arc. Finally it joins the Gulf of Guinea on the Atlantic Ocean.
One of the greatest Asian rivers, the Indus is about 1,980 miles (3,180 km) long, and its catchment basin drains an area of more than 425,000 square miles (1.1 million square km).
From its source near Lake Manasarovar on the Tibetan Plateau, the Indus flows northwest through the disputed territory of Jammu and Kashmir, turns southwest to enter Pakistan, and passes through a series of huge canyons near the Nanga Parbat Massif on its journey across the Himalayas.
Emerging from the mountains as a fast-flowing river, the Indus descends onto the Punjab Plain, where it is joined by some of its major tributaries and begins to move slowly across a vast floodplain. During the monsoon season, the Indus can grow to a couple of miles wide in places.
As it approaches the Arabian Sea, the river branches into the many distributaries that form the Indus River Delta.