thumb|[[Meeting of Waters. Confluence of the Solimões (whitewater) and the Rio Negro (blackwater) near Manaus.]]
thumb|The Congo River allegory by [[Thomas Vinçotte.]]
Rivers are natural drainage channels. They collect runoff from precipitation and groundwater and discharge it into oceans or lakes. The main watercourse is determined by its water volume, length, or highest source. River size is determined by three factors: discharge, length, and drainage basin.
Discharge measurements
The global annual runoff into the oceans (38,500–44,200 km<sup>3</sup>/year) is dominated by runoff into the South Atlantic from eastern South America, into the western Pacific from east Asia, and into the Indian Ocean from India, and southeast Asia. Depending on the estimate, the Amazon alone accounts for 15–18% of the annual freshwater runoff into the oceans.
<gallery mode="packed" widths="300" heights="200" style="text-align:left">
File:Rivers of the world by discharge volume.png|Circle represents total global river discharge of 38,500 km³/year
Total_global_runoff_rate_by_continent_and_oceans.jpg|Total global runoff rate by continent and oceans
Riverfunoffoceans.jpg|Largest primary rivers by runoff
</gallery>
Water discharge may be expressed as mean annual discharge (denoted MQ), or as annual discharge (denoted Q). The units for measuring mean annual discharge (MQ) are m³/sec, and can be measured over a period of one or more years. The annual discharge (Q) is measured in units of km³/year. For large rivers, these values difficult to measure (see ADCP), and they also vary considerably from year to year. The very large variation between low and high flow is often not apparent from the average runoff volume.
The discharge values shown in the tables below are mean annual discharge (units m/sec). To convert to annual discharge (units km/year) multiply by 0.031536.
List of rivers
{| class="wikitable"
|- bgcolor="#CCCCCC"
!colspan="6" align="center"|Continent color key
|-
|bgcolor="#CCCCFF"|Africa
|bgcolor="#FFCBCB"|Asia
|bgcolor="#CCFF66"|Oceania
|bgcolor="#FFCCFF"|Europe
|bgcolor="#CCFFFF"|North America
|bgcolor="#FFEBAD"|South America
|}
{| class="wikitable"
|- bgcolor="#CCCCCC"
!colspan="5" align="center"|Ocean color key
|-
|bgcolor="#E0FFFF"|Atlantic Ocean
|bgcolor="#E6E6FA"|Pacific Ocean
|bgcolor="#F0FFF0"|Indian Ocean
|bgcolor="#FFF0F5"|Arctic Ocean
|bgcolor="#FFF8DC"|Endorheic
|}
{| class="sortable col1right col4right col5right col6right" style="border: 1px solid #999; background-color:#ffffff;font-size:90%;"
|- bgcolor="#BDBBD7" style="color:#000080;text-align:center;font-size:105%;"
! rowspan="2" | No
! colspan="2" | River name
! rowspan="2" | Average<br />discharge<br />(m³/s)
! rowspan="2" | Length<br />(km)
! rowspan="2" | Outflow
! rowspan="2" | Notes, references
|- bgcolor="#BDBBD7" style="color:#000080;text-align: center;font-size:105%;"
!Primary
!Tributary
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD"|SA1|| Amazon
||| || || ||bgcolor="#E0FFFF" |Atlantic Ocean||
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF2|| Congo
| || || || || bgcolor="#E0FFFF" |Atlantic Ocean ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB"|AS4||Yangtze
| || || ||||bgcolor="#E6E6FA" |East China Sea||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF"|NA8||Mississippi
| || |||| || bgcolor="#E0FFFF" |Gulf of Mexico||
|- bgcolor="#EFEFEF"
|bgcolor="#FFCBCB"|AS9||Yenisei
| || || || || bgcolor="#FFF0F5" |Yenisei Gulf||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD"|SA10||Paraná
| || || || || bgcolor="#E0FFFF" |Río de la Plata||
|-bgcolor="#EFEFEF"
|bgcolor="#FFCBCB"|AS11|| Lena
| || || || ||bgcolor="#FFF0F5"|Laptev Sea||
|-bgcolor="#EFEFEF"
|bgcolor="#FFCBCB"|AS14||Mekong
| || || || ||bgcolor="#E6E6FA"|South China Sea||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB"|AS15|| Ganges
| || || || || bgcolor="#F0FFF0" |Padma, Bay of Bengal||
|-bgcolor="#EFEFEF"
|bgcolor="#FFCBCB"|AS17||Ob
| || || || ||bgcolor="#FFF0F5"|Gulf of Ob||
|-bgcolor="#EFEFEF"
|bgcolor="#FFCBCB"|AS21||Amur
| || || || ||bgcolor="#E6E6FA"|Strait of Tartary||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD"| SA22|| Tocantins
| || || || || bgcolor="#E0FFFF" |Rio Para ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS24|| Pearl River
| || || || || bgcolor="#E6E6FA" |South China Sea ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF25||
|Kasai|| || || || bgcolor="#E0FFFF" |Congo ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA26||Mackenzie
| || || || || bgcolor="#FFF0F5" |Beaufort Sea||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA27||
|Beni|| || || || bgcolor="#E0FFFF" |Madeira ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA28
|
|Xingu || || || || bgcolor="#E0FFFF" |Amazon ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA30||
|Putumayo|| || || || bgcolor="#E0FFFF" |Solimões ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA32||
|Ohio|| || || || bgcolor="#E0FFFF" |Mississippi ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA33||Magdalena
| || || || || bgcolor="#E0FFFF" |Caribbean Sea||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" | SA34||
|Mamoré|| || || || bgcolor="#E0FFFF" |Madeira||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA37|| Uruguay
| || || || || bgcolor="#E0FFFF" |Río de la Plata ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA39||
|Napo|| || || || bgcolor="#E0FFFF" |Amazon ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS40|| Salween
| || || || || bgcolor="#F0FFF0" |Andaman Sea ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFF66" |OC41|| Fly
| || || || || bgcolor="#E6E6FA" |Gulf of Papua||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCCFF" |EU42|| Danube
| || || || || bgcolor="#E0FFFF" |Black Sea||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA43||
|Araguaia|| || || || bgcolor="#E0FFFF" |Tocantins ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA46||
|Juruá|| || || || bgcolor="#E0FFFF" |Solimões ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA49
|
|Meta || || || || bgcolor="#E0FFFF" |Orinoco ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS51||
|Aldan || || || || bgcolor="#FFF0F5" |Lena ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA53
|
|Rio Branco|| || || || bgcolor="#E0FFFF" |Rio Negro ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA55
|
|Javary|| || || || bgcolor="#E0FFFF" |Solimões ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFF66" |OC57||Mamberamo
| || || || || bgcolor="#E6E6FA" |Pacific Ocean||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFF66" |OC58||Sepik
| || || || || bgcolor="#E6E6FA" |Bismarck Sea||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA59||
|Caroní || || || || bgcolor="#E0FFFF" |Orinoco ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA67||
|Paraguay|| || || || bgcolor="#E0FFFF" |Paraná ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA70
|
|Vaupés || || || || bgcolor="#E0FFFF" |Rio Negro ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS72|| Mahakam
| || || || 980 || bgcolor="#E6E6FA" |Makassar Strait||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS73||
|Lower Tunguska|| || || || bgcolor="#FFF0F5" |Yenisei ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCCFF" |EU76||
|Kama|| || || || bgcolor="#FFF8DC" |Volga ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA81|| Fraser|| || || || || bgcolor="#E6E6FA" |Strait of Georgia||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA82||
|Teles Pires|| || || || bgcolor="#E0FFFF" |Tapajós ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA83
|
|Huallaga || || || || bgcolor="#E0FFFF" |Marañón ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCCFF" |EU86|| Northern Dvina
| || || || || bgcolor="#FFF0F5" |White Sea||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA88||
|Caura || || || || bgcolor="#E0FFFF" |Orinoco ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS96|| Khatanga
| || || || || bgcolor="#FFF0F5" |Khatanga Gulf||
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF99|| Nile
| || || || || bgcolor="#E0FFFF" |Mediterranean Sea||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS100|| Musi
| || || || 759 || bgcolor="#E6E6FA" |South China Sea ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA101||
|Tigre || || || || bgcolor="#E0FFFF" |Marañón ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS106||
|Irtysh|| || || || bgcolor="#FFF0F5" |Ob ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS112
|
|Gan || || || || bgcolor="#E6E6FA" |Lake Poyang ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA115||
|Missouri|| || || || bgcolor="#E0FFFF" |Mississippi ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA116
|
|Guaporé || || || || bgcolor="#E0FFFF" |Mamoré||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS119
|
|Mali Hka|| || || || bgcolor="#F0FFF0" |Irrawaddy ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA121||San Juan
| || || || 399 || bgcolor="#E6E6FA" |Pacific Ocean ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS124||
|Songhua || || || || bgcolor="#E6E6FA" |Amur ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA142||Jacuí
| || || || 800 || bgcolor="#E0FFFF" |Lagoa dos Patos||
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF150||
|Aruwimi || || || || bgcolor="#E0FFFF" |Congo ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA153||
|Ventuari|| || || || bgcolor="#E0FFFF" |Orinoco ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA156||
|Tennessee || || || || bgcolor="#E0FFFF" |Ohio ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS157
|
|Lohit || || || || bgcolor="#F0FFF0" |Brahmaputra ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS161||
|Olyokma|| || || || bgcolor="#FFF0F5" |Lena ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF164
|
|Lomami || || || || bgcolor="#E0FFFF" |Congo ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFF66" |OC168|| Kikori
| || || || 445 || bgcolor="#E6E6FA" |Gulf of Papua ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS175
||Indigirka
| ||
||
||
| bgcolor="#FFF0F5" |East Siberian Sea
|
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA177||
|Caguán || || || 596|| bgcolor="#E0FFFF" |Caquetá ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA184||
|Iguaçu|| || || || bgcolor="#E0FFFF" |Paraná ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS190
||Great Tenasserim
| ||
||
||616
| bgcolor="#F0FFF0" |Andaman Sea
|
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA192||
|Snake|| || || || bgcolor="#E6E6FA" |Columbia||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCCFF" |EU199
||Dnieper
| ||
||
||
| bgcolor="#E0FFFF" |Black Sea
|
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS200||
|Wu|| || || || bgcolor="#E6E6FA" |Yangtze ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF210||
|Blue Nile|| || || || bgcolor="#E0FFFF" |Nile||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA217
||Koksoak
| ||
||
||588
| bgcolor="#FFF0F5" |Ungava Bay
|
|- bgcolor="#EFEFEF"
| bgcolor="#FFCCFF" |EU220
||Po
| ||
||
||652
| bgcolor="#E0FFFF" |Adriatic Sea
||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA221||
|Dos Marmelos|| || || 560|| bgcolor="#E0FFFF" |Madeira ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCCFF" |EU227||
|Usa || || || 565|| bgcolor="#FFF0F5" |Pechora||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA229||
|Vichada|| || || || bgcolor="#E0FFFF" |Orinoco ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA232
||Grijalva
| ||
||
||
| bgcolor="#E0FFFF" |Usumacinta
|
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA235
||Patía
| ||
||
||430
| bgcolor="#E6E6FA" |Pacific Ocean
|
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA241||Albany
| ||
||
||832
| bgcolor="#FFF0F5" |James Bay
|
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF244
||Betsiboka|| ||
||
||531
| bgcolor="#F0FFF0" |Mozambique Channel
|
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA245||
|Mazaruni|| || || 560|| bgcolor="#E0FFFF" |Cuyuní ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA265
|
|Takutu|| || || 371|| bgcolor="#E0FFFF" |Rio Branco ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA286||
|Casanare|| || || 415|| bgcolor="#E0FFFF" |Meta ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA305||
|Ibicuí|| || || 673|| bgcolor="#E0FFFF" |Uruguay ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA379
|
|Maués Açu|| || || || bgcolor="#E0FFFF" |Paraná do Urariá ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS425||
|Indaw Chaung|| || || 308|| bgcolor="#F0FFF0" |Irrawaddy ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS445
|
|Tuba || || || || bgcolor="#FFF0F5" |Yenisei ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFCBCB" |AS476
|
|Gyaing|| || || 250|| bgcolor="#F0FFF0" |Salween ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA498
|
| Río Grande o Guapay || || || || bgcolor="#E0FFFF" |Mamoré ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF517
|
|Alima|| || || || bgcolor="#E0FFFF" |Congo ||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA529
|
|Mapuera|| || || || bgcolor="#E0FFFF" |Trombetas ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF534
| Konkouré|| ||
||
||
| bgcolor="#E0FFFF" |Baie de Sangareya
|
|- bgcolor="#EFEFEF"
| bgcolor="#FFCCFF" |EU537
|Daugava|| ||
||
||
| bgcolor="#E0FFFF" |Gulf of Riga
|
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA546
|
|Río Blanco|| || || || bgcolor="#E0FFFF" |Guaporé ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCCCFF" |AF586
|
|Kotto|| || || || bgcolor="#E0FFFF" |Ubangi ||
|- bgcolor="#EFEFEF"
| bgcolor="#CCFFFF" |NA592
|Pánuco|| ||
||
||
| bgcolor="#E0FFFF" |Gulf of Mexico
|
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA607
|
|Perené|| || || || bgcolor="#E0FFFF" |Tambo||
|- bgcolor="#EFEFEF"
| bgcolor="#FFEBAD" |SA614
|
|Samiria|| || || || bgcolor="#E0FFFF" |Marañón ||