The rivers are great depositories of water and they have sustained civilizations since advent of time. When they flow in their full bloom it is a sight for the God's to watch. The energy they ooze while flowing from the mountains into the seas is simply difficult to imagine. If they support life, then during monsoons they can take it back also. If interfered with they can hit back with immense fury and cause untold damages to both life and property. No doubt that in many cultures rivers are respected and even worshiped.
Five great rivers of the world are presented below in no order of preference :
Amazon River
The Amazon river originates in Lago Villafro in the Andes mountains, Peru and passes through Ecuador, Brazil and Colombia, in South America. It flows from west to east and finally discharges into the Atlantic Ocean. It is believed to be the second largest river in the world after river Nile. However many studies have shown that it could be larger than Nile also. Its length is estimated to be anywhere up to 6,800 kms but not less than 6,400 kms.
Its source is in the Andes mountains at an elevation of 5,170 meters and its mouth is the Atlantic Ocean at ground level. Over 1,100 tributaries flow into it from both sides, 17 of which are more than 1,500 kms long.The Amazon River width varies from 1.6 km to 10 kms but can widen to 48 kms during monsoon season. Its mouth at the Atlantic Ocean is about 80 kms wide. Such gigantic dimensions often make people refer to it as River Sea.
The quantity of water released by Amazon into Atlantic Ocean is so enormous that an area of 26,00,000 square kms of the Ocean is covered by the lighter river waters. The river is estimated to discharge at the rate of 3,00,000 cubic meter per second during monsoon and around 2,00,000 cubic meters per second in normal times. Amazon River discharges nearly 20% of the earth's fresh water into the sea.
The river has a drainage basin of around 70,50,000 square kms the largest in the world and accounts for nearly 20% or 1/5th of the world's total fresh water flows into the sea and covers nearly 40% of South America. It thus makes it a very important river in S. America and the world. The Amazon rain forest covers the areas of nine countries: Brazil, Peru, Ecuador, Venezuela, Bolivia, Colombia, Gyuana, Suriname and French Guiana.
The Amazon River surroundings are extensively forested and support a large variety of flora and fauna, many of which are unique to this area. More than 2,000 variety of fish are found in the Amazon Basin, including the deadly meat eating piranha fish. In the Amazon rain forest area more than one third of the known species of the world exist. The famous snake Anaconda. longest in the world, is native to this region. Large size dolphins are also found.
An interesting feature was discovered and made public in 2011. The discovery was made by an Indian scientist Valiya Hamza, who showed that below the Amazon River flows a parallel underground river, named Hamza river in his honour. It is the longest underground river in the world and its length is about 6,000 kms at a depth of 4 kms. As compared to the width variation of Amazon between 1.6 km to 100 kms in monsoon the Hamza has a width variation of 200 kms to 400 kms and it flows at a speed of only a millimeter per second compared to five meters per second speed of Amazon River.
The Amazon River is truly a gigantic river of mammoth proportions.
Nile River
The Nile River is recognized as the longest river in the world. Its waters are shared by eleven African countries like Egypt, Congo,Tanzania, Rawanda, Uganda, Sudan, Ethiopia, Kenya, Eriteria, Burundi and South Sudan. It flows in the north eastern region of Africa and it ends in a large delta that discharges into the Mediterranian Sea. It is 6.650 kms in length. It has an average width of 2.8 km and average discharge of 2,830 cubic meter per second.
The source of the river is usually considered to be Lake Victoria, but it is itself fed by larger rivers Like River Kagera, and the farthest source is thus not exactly still established. The Nile River has two main tributaries flowing into it known as the White Nile and the Blue Nile. The larger White Nile originates in either Rwanda or Burundi and the Blue Nile originates in lake Tana in Ethiopia. Both these rivers meet at Khartoum,the capital of Sudan.
The Nile River drains an area of 32,54,555 square kms about 10% of Africa. It is closely associated with Egypt through the ages. All major cties of Egypt are by its side and because of it, Egyptians are able to live in the Saharan desert. The building of Aswan Dam in Egypt has resulted in control of the flow of Nile and has brought a change in agriculture practices. The river was used as a major source of transportation and is in use for it today also.
Some of the important cities on it are Jinja, Juba, Khartoum and Cairo. The great contribution of River Nile is the fact that it flows towards North Africa through desert whch would be otherwise be uninhabitable but for the waters it brings. It has been doing so from eternity and the Egyptian civilisation flourished on its banks centuries ago. The Pyramids of the Pharoes got built because River Nile flowed by in the adjoining deserts.
Yangtze River
The Yangtze River is Asia's longest and the world's third longest river. It entirely flows within China. It originates in the Tibet plateau in Quinghai and flows across southwest, central and eastern China. Its mouth is at the East China Sea at Shanghai. It drains nearly one-fifth of China's area and nearly 33% of China's population is living in its basin. It is 6,418 kms in length.
It is also seen as acting as a dividing line between North China and South China ,whose climate, culture, economics etc vary differentlly from each other.
It's source is located in the glaciers of the west of the Geladandong mountains in Tibet at an elevation of 5,042 meters. Its basin is spread in an area of 18,08,500 square kms. It has one of the biggest river discharge volumes in the world at an average of 30,166 cubic meter per second peaking to 1,10,000 cubic meter per second in wet season and falling to 2,000 cubic meter per second in lean season. Its river basin is 18,00,000 square kms.
Some of the well known cities along its banks are Wuhan, Zhenjiang, Nanjing, Jingzhou, Nantong and Shanghai. It is estimated that it contributes nearly 20 % of Chinese GDP. The river is a busy waterway transporting more than 800 million tons of cargo annually. It also flows through the most beautiful and scenic Three Gorges area which attracts increasing tourist traffic every year. Curiously, the first bridge across the river was built in 1957. Now hundreds of crossings and couple of tunnels have been built across the river.
Two dams have been built on the river. The Three Gorges Dam and the Ghezhouba Dam for generation of hydel power and regulation of water flow for agricultural purposes. The former is the largest hydro electric power station in the world. Due to rapid industrialization in China, the river has suffered from industrial pollution, heavy silting, agricultural runoffs and loss of its drainage areas, leading to heavy flooding resulting in considerable loss of property and life.
Historically, battles have been fought by the British, Americana and French with the Chinese Kings to get the right to navigate on the Yangtze River for commerce purposes. In one such fight in 1843 the Chinese were forced to cede Hong Kong to Queen Victoria and it remained with the British till 1997.
Alongwith another of China's great river, the Yellow River, it forms the cradle of the great Chinese Civilization.
Mississippi River
The Mississippi River, meaning Great River, flows entirely within the Central part of the United States. It originates in Lake Itasca in Minnesota the North at an elevation of 450 meters, runs through Central region of America into the Gulf of Mexico down south.Together with its major tributary, Missouri River, the combined Mississippi- Missouri River is the third (?) or fourth longest river in the world, with a length of 5,970 kms. Here we shall discuss the Mississippi River whose length is 3,770 kms.
The mighty Missouri River is one of its tributaries and their confluence takes place at St. Louis, Missouri. From its origin till here, it is known as the Upper Mississippi River. In between there are 43 dams which regulate its flow and generate power and spread irrigation. From St Louise till its meeting with another of its tributary, the Ohio River at Cairo, Illinois it is known as the Middle Mississippi. From here till Gulf of Mexico it is known as the Lower Mississippi. Further tributaries drain into the Mississippi river like White River ,Big Black River, Yazoo river and Red River during its course ae the Lower Mississippi.
The Mississippi River forms the fourth largest drainage basin in the world covering 32,20,000 square kms area which includes 32 US states and two provinces of Canada. It discharges at the rate between 7,000 to 20,000 cubic meters per second equivalent to only around 8% of the Mighty Amazon River flow.
The first brdge across the river was built in 1855 and the first railroad bridge was buit in 1856.Today a large number of bridges some of great engineering feats are built on the Mississippi River. Some of the cities situated on its banks are Minnesota, Wisconsin, Iowa, Illinois, Kentucky, Tennessee, Louisiana, Arkansas and Missouri.
Together the Mississippi and Missouri Rivers form a great waterway sytem and their basin covers around 40% of the US and also supports its economy in a big way.
Ganga River
The Ganga River flows within India and Bangladesh. It originates in the Himalayas in Uttrakhand at an elevation of 3,892 meters and flows southward and then east into Bangladesh where it meets the Bay of Bengal. It is the largest river in India with a length of 2,525 kms and the second largest river in the world for water discharge, ranging from 2,000 to 70,000 cu. meter per second with an average of 12,500 cu. meter per second. It covers a basin of 10,80,000 square kms.
Its main source is the Gangotri Glacier amongst other adjoining glaciers and the melted snows of peaks like Nanda Devi, Kedarnath etc. The major cities on its banks are Haridwar, Allahabad, Kanpur, Varanasi, Rishikesh, Bhagalpur and Kolkatta. Some of its major tributories are Yamuna, Ramganga, Gomti, Son, Koshi, Ghaghara and Mahananda rivers. It flows through the States of Uttrakhand, UP, Bihar, Jharkhand and West Bengal.
The Ganga River begins at the confluence of Bhagirathi and Alaknanda. Alaknanda is formed by the waters of the melted snows of the peaks like Nanada Devi and Bhagirathi begins at the foot of the Gangotri Glacier at Gaumukh.
The Ganga flows for about 250 kms in the narrow Himalayan Valley and emerges from the mountains at Rishikesh. It then enters the Gangetic Plain in Haridwar. From here it also starts its southeastern journey through north India. The Ganga joins the Yamuna at Sangam near Allahabad and then starts flowing towards Malda in West Begal. It enters into Bagladesh where it is known by the name of Padma and later on as the Meghna before it enters into the Meghna Estuary and empties into the Bay of Bengal.
The Ganges delta is the largest in the world and is formed by the sediment laden flows of both the Ganga and the Brahamaputra rivers. It size is about 59,000 square kms. The discharge from the combined Ganga and Brahamaputra is only next to that from Amazon and Congo Rivers.
Ganga River has a tremendous religious significance for Hindus and is revered as mother by them. A bath in the Ganga is supposed to wash away the sins of the bather. Hindu mythology is full of stories of Ganga and Shiva the God whose abode are the Himalayan mountains. Ancient visitors from Greece and China mention the Ganga repeatedly in their writings and the important role it played in the culture of ancient Indians.
The Ganges delta is very fertile and contributes to agriculture produce significantly. It is also being increasingly used for generating hydroelectric power. However due to the variety of industries on its banks and their discharge into it have made Ganga a very polluted river. It is a dead river at many places. It supports the breeding of large variety of fish and other aquatic species including dolphins. It is a big provider of water to agriculture around it.
However it also floods the Gangetic Plain causing destruction during the monsoon season. It is a great holy river which is embedded deeply in Indian culture and this makes it one of the Great Rivers of the world.