In hydrology, discharge refers to the rate of fluid flowing in a given unit of time. It is also known as volume velocity or volume flow rate. River discharge is measured in cubic feet per second or meters cubic per second.
A drainage basin refers to the region where precipitation accumulates and finally drains off into a collective outlet like a river. The drainage basin may include runoff water on the surface, and even snowmelt, including streams in the surrounding area that drain into a shared outlet. It also includes groundwater which is underneath the surface of the earth. The fastest moving rivers or rivers with the highest discharge include the following:
The Amazon River
The Amazon River is found in the continent of South America and is the largest river in the world regarding discharge by volume. It is one of the longest rivers in the world covering a distance of 4,132 miles. The source of the Amazon River was initially thought to be Apurimac River until in 2014 when it was adjusted that the source of the Amazon River is in cordillera Rumi Cruz at the source of Mantaro River in Peru. The Amazon River discharges 7,380,765 cubic feet per second of water, and it represents 20% of the world's riverine discharge into the ocean. The Amazon basin is now the largest water drainage basin in the world covering an area of 2,720,000 square miles. The Amazon River begins its journey from the Andes in Peru and traverses through Bolivia, Colombia, Ecuador, and Brazil before draining into the Atlantic Ocean.
The Congo River is Africa’s second longest river and the world’s second-largest by discharge volume. The Congo River is also the world's deepest river with a depth reaching 720 feet deep at its deepest point. The river covers a distance of 2,920 miles long making it the world’s 9th longest river, and it is the only river that crosses the equator twice. The Congo basin covers an area of 1,500,000 square miles which is approximately about 13% of Africa’s landmass. The Congo River has an average discharge of 1,454,964 cubic feet per second. The source of Congo River is in the mountains and islands of East African rift valley and the Lake Mweru and Lake Tanganyika. The river runs in the Democratic Republic of the Congo and drains into the Atlantic Ocean.
Ganges – Brahmaputra – Meghna
The Ganges, Brahmaputra, and Meghna rivers are located in Eurasia and have a combined length of 3,371 miles. The Ganges River flows through Bangladesh and India covering a distance of 1,569 miles. The river originates in the Himalayas, and the farthest point is thought to be in the state of Uttarakhand in India, where it flows to the south-east passing through the Ganges plains in the northern part of India before draining to the Bay of Bengal. Brahmaputra River flows through China, India, and Bangladesh uncovers. It originates in the part of the Himalayas in Tibet and into Pradesh in India and finally to Bangladesh and drains into the Bay of Bengal. Meghna River is wholly in Bangladesh and forms the largest delta in the world fanning out into the Bay of Bengal. The three rivers have a drainage area covering 668,472 square miles and have an average discharge flow approximately 1,346,513 cubic feet per second and finally discharge into the Bay of Bengal.
Significance Of Rivers
Rivers plays a vital role in the water cycle and serve as a channel to drain the water on the surface of the earth. Rivers also transport water nutrients to different parts of the world. It is thought that rivers in general drain approximately 75% of the surface of the earth. Rivers are also a habitat for different species and are therefore a source of food for different organisms. Rivers also can serve as travel routes and may be used for recreation, commerce, and exploration. Water in the rivers is a significant resource and can provide a soured of hydropower among other economic activities.