The Napo River () is a

tributary A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...

to the Amazon River that rises in

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

on the flanks of the east

Andean The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long and wide (widest between 18°S ...

volcano A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most oft ...

es of

Antisana Antisana is a stratovolcano of the northern Andes, in Ecuador. It is the fourth highest volcano in Ecuador, at , and is located SE of the capital city of Quito. Antisana presents one of the most challenging technical climbs in the Ecuadorian An ...

, Sincholagua and

Cotopaxi Cotopaxi () is an active stratovolcano in the Andes Mountains, located near Latacunga city of Cotopaxi Province, about south of Quito, and northeast of the city of Latacunga, Ecuador. It is the second highest summit in Ecuador (after Chim ...

. The total length is . The river drains an area of ca 103,000 km². The mean annual discharge at Mazán .

Geography

Before it reaches the plains it receives a great number of small streams from impenetrable, saturated and much broken mountainous districts, where the dense and varied vegetation seems to fight for every piece of ground. From the north it is joined by the

Coca River The Coca River is a river in eastern Ecuador. It is a tributary of the Napo River. The two rivers join in the city of Puerto Francisco de Orellana Puerto Francisco de Orellana (), also known as El Coca (), is the capital of province of Orell ...

, having its sources in the gorges of

Cayambe volcano Cayambe or Volcán Cayambe is a volcano in Ecuador, in the Cordillera Central, a range of the Ecuadorian Andes. It is located in Pichincha Province, some northeast of Quito. It is the third-highest mountain in Ecuador, at an elevation of above ...

on the

equator The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...

, and also a powerful river, the Aguarico having its headwaters between Cayambe and the

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

frontier. From the west, it receives a secondary tributary, the

Curaray The Curaray River (also called the Ewenguno River or Rio Curaray) is a river in eastern Ecuador and Peru. It is a tributary of the Napo River, which is part of the Amazon basin. The land along the river is home to several indigenous people groups, ...

, from the

slopes, between Cotopaxi and the

Tungurahua volcano Tungurahua (; from Quichua ''tunguri'' (throat) and ''rahua'' (fire), "Throat of Fire")) is an active stratovolcano located in the Cordillera Oriental of Ecuador. The volcano gives its name to the province of Tungurahua. Volcanic activity rest ...

. From its Coca branch to the mouth of the Curaray the Napo is full of snags and shelving sandbanks and throws out numerous canoes among jungle-tangled islands, which in the

wet season The wet season (sometimes called the rainy season or monsoon season) is the time of year when most of a region's average annual rainfall occurs. Generally, the season lasts at least one month. The term ''green season'' is also sometimes used a ...

are flooded, giving the river an immense width. From the Coca to the Amazon it runs through a forested plain where not a hill is visible from the river - its uniformly level banks being only interrupted by

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

s and

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

s. From the Amazon the Napo is navigable for river craft up to its Curaray branch, a distance of about , and perhaps a bit further; thence, by painful canoe navigation, its upper waters may be ascended as far as ''Santa Rosa'', the usual point of embarkation for any venturesome traveller who descends from the

Quito Quito (; ), officially San Francisco de Quito, is the capital city, capital and second-largest city of Ecuador, with an estimated population of 2.8 million in its metropolitan area. It is also the capital of the province of Pichincha Province, P ...

tableland. The Coca river may be penetrated as far up as its middle course, where it is jammed between two mountain walls, in a deep canyon, along which it dashes over high falls and numerous reefs. This is the stream made famous by the expedition of the Spanish

conquistador Conquistadors (, ) or conquistadores (; ; ) were Spanish Empire, Spanish and Portuguese Empire, Portuguese colonizers who explored, traded with and colonized parts of the Americas, Africa, Oceania and Asia during the Age of Discovery. Sailing ...

Gonzalo Pizarro Gonzalo Pizarro y Alonso (; 1510 – 10 April 1548) was a Spanish conquistador. He was the younger paternal half brother of Francisco Pizarro, who led the Spanish conquest of the Inca Empire. Pizarro was the illegitimate son of Gonzalo Pizarro y ...

. Hydrometric stations on the Napo River:

Discharge

Napo River at Bellavista average (Q), dominante (Q_d) discharge (m³/s) and

sediment load {{page numbers needed, date=November 2020 Stream load is a geologic term referring to the solid matter carried by a stream (Strahler and Strahler, 2006). Erosion and bed shear stress continually remove mineral material from the bed and banks of ...

(S – million ton/year). Period from 1991/09–2009/08: Napo River at Bellavista average, minimum and maximum discharge (m³/s). Period from 2009/09 to 2023/08: Minimum 498.6 m³/s (2016/02); Maximum: 15,820 m³/s (2015/07); Napo River at Bellavista average, maximum, minimum and multiannual average (normal) discharge (m³/s) and anomaly (%):

Tributaries

List of the major tributaries of the Napo River (from the mouth upwards): ^*Period: 1971–2000

References

{{Authority control Tributaries of the Amazon River Rivers of Ecuador Rivers of Peru International rivers of South America Rivers of the Department of Loreto Geography of Napo Province Geography of Orellana Province Geography of Sucumbíos Province Upper Amazon

Geography

Discharge

Tributaries

See also

References