Asia’s vital rivers

The headwaters of 10 major rivers originate near some of Earth’s highest points. Known as the world’s “third pole,” the land of Mount Everest and other peaks holds the largest concentration of perennial ice outside of the polar regions. Along with snow and rain from the mountains, this ice helps supply the river basins below that support the water, food, and energy needs of almost two billion people.

Published june 16, 2020

Yellow

Tarim

Amu Darya

Yangtze

Indus

Mekong

Ganges-

Brahmaputra

Irrawaddy

Salween

Snow, ice, and rain

power the rivers

Downstream populations rely heavily on mountain water. Meltwater helps regulate

the seasonal pattern of river flows and boost water supply outside of the monsoon season, but climate change may weaken this buffering role. Meltwater dependence is highest in the Indus Basin.

River flow composition in the upper basins

BASE

RAINFALL

SNOWMELT

GLACIER MELT

40.6%

of flow

INDUS

Surface area of upstream basin:

163,514 square miles

15.9%

BRAHMAPUTRA

142,665

11.5%

8.3%

0.9%

GANGES

64,904

MEKONG

39,344

SALWEEN

29,344

† Flow released from groundwater

Shrinking glaciers

Many of the region’s glaciers have been losing mass since the mid-1800s, and the rate of ice loss is increasing. They shed 19 gigatons of ice each year from 2000 to 2018, with glaciers in the Brahmaputra, Indus, and Ganges Basins seeing the greatest declines.

Agriculture at the ‘third pole’

Regional and global food supplies depend on water from these mountains. The river basins produce 34 percent of the world’s rice (half of which is grown in the Yangtze Basin) and 17 percent of the world’s sugarcane. Both are highly water-intensive crops.

SUGARCANE

Global production, 2018

2,077 million tons

CORN

1,233

All basins

17%

10%

POTATO

28%

23%

403

WHEAT

786

34%

RICE

742

‘Towers’ release

stores of water

Mountains act as natural water towers by

storing and providing freshwater

downstream. Each tower’s importance is

ranked by determining how much water it

can supply relative to downstream

availability and demand; some areas, for

example, have more rainfall, which can

lessen their dependence on meltwater. But

this source is vulnerable to climatic and

economic changes.

10 million people

living in river

basin, 2015

The water tower index examines supply from glacier melt, snowmelt, rain, and surface water against downstream environmental, industrial, household, and irrigation demands.

Amu Darya

Human activities have dramatically altered natural ecosystems in the Amu Darya Basin. Extensive water diversions for irrigation from the Amu Darya and the Syr Darya contributed to the shrinking and collapse of the Aral Sea.

Supply

High

Low

Demand

Amu Darya

* includes reservoirs

Indus

The Indus Basin contains the world's largest contiguous irrigation system, one critically important to food security and water supply. But increasing demands and climate change threaten the future availability of water.

Indus

Ganges-Brahmaputra

Sacred to Hindus, the Ganges River merges with the Brahmaputra and Meghna Rivers before flowing into the Bay of Bengal. The densely populated delta is particularly susceptible to sea-level rise and coastal storms.

Ganges-

Brahmaputra

Irrawaddy

The Irrawaddy River Basin is the largest in Myanmar and home to six major cities. The Chinese-financed Myitsone Dam project-

approved in the 2000s and halted in

2011- remains very controversial.

Irrawaddy

Salween

The 1,700-mile Salween River remains largely free-flowing: The basin is one of the least modified in Southeast Asia. About 18 million people from more than 15 ethnic groups rely on the river basin for their livelihoods.

Salween

Mekong

Cooperation is a challenge along the Mekong River, which winds through six countries. It's the world's second most biodiverse river and supports the largest inland fishery. Dam construction is disrupting migratory fish routes.

Mekong

Yangtze

Asia's longest river flows through the Three Gorges Dam, the world's largest hydroelectric plant. The South-North Water Diversion Project could divert up to 1.7 trillion cubic feet of water a year to the Yellow River when finished.

Yangtze

Yellow

Known as the cradle of Chinese civilization, the Yellow River Basin is a key breadbasket. Demand for water outstrips supply, which diminishes discharge to the ocean. This deficit likely will be exacerbated by climate change.

Yellow

Tarim

The Tarim flows through Xinjiang, an increasingly significant cotton-growing region. The Tarim Basin produced 15 percent of the global cotton supply in 2018. Intensive agriculture is straining the basin's water resources.

Tarim

Supplement to National Geographic, July 2020

This poster was supported by Rolex, which is partnering with the National Geographic Society to shine light on the challenges facing the Earth's critical life-support systems through science, exploration, and storytelling.

Editors: Matthew W. Chwastyk, Jason Treat, and Martin Gamache

Research: Irene Berman-Vaporis and Taryn Salinas; Edward Benfield

Cartography: Eric Knight

Text: Eve Conant

Map Edit: Scott Zillmer

Design: Elaine Bradley

Sources: Arthur Lutz and Walter Immerzeel, Utrecht University; David Molden, Arun Shrestha, and Birendra Bajracharya, International Centre for Integrated Mountain Development; David Shean, University of Washington; Hester Biemans, Wageningen Environmental Reasearch; Christian Siderius, Uncharted Waters Reasearch; Stephen Darby, University of Southampton; Til Feike, Julius Kühn-Institut; Vanessa Lamb, University of Melbourne; Darrin Magee, Hobart and William Smith Colleges; Robert Nicholls, University of East Anglia; NASA, GFSAD Croplands; Landscan 2018 high-resolution population data; European Commission's Global Surface Water Explorer

MT. EVEREST

29,035 ft

8,850 m

Urban area

River basin

boundary

Cropland

Scale varies in this perspective.

Snow, ice, and rain power the rivers

Downstream populations rely heavily on mountain water. Meltwater helps regulate the seasonal pattern of river flows and boost water supply outside of the monsoon season, but climate change may weaken this buffering role. Meltwater dependence is highest in the Indus Basin.

River flow composition in the upper basins

BASE

RAINFALL

SNOWMELT

GLACIER MELT

11.5%

40.6%

8.3%

0.9%

15.9%

of flow

GANGES

64,904

MEKONG

39,344

SALWEEN

29,344

INDUS

Surface area of upstream basin:

163,514 square miles

BRAHMAPUTRA

142,665

† Flow released from groundwater

Shrinking glaciers

Many of the region’s glaciers have been losing mass since the mid-1800s, and the rate of ice loss is increasing. They shed 19 gigatons of ice each year from 2000 to 2018, with glaciers in the Brahmaputra, Indus, and Ganges Basins seeing the greatest declines.

Kaidu

Kaidu

Kashgar

Kashgar

Aksu

Aksu

Vakhsh

Vakhsh

Yarkant

Yarkant

Qarqan

Qarqan

Upper Yellow

Upper Yellow

Zarafshon

Zarafshon

Keriya

Keriya

Tongtian-Yangtze

Tongtian-Yangtze

Sherabod

Sherabod

Hotan

Hotan

Shyok

Shyok

Gilgit

Gilgit

Nu-Salween

Nu-Salween

Kunaṟ

Kunaṟ

Upper Indus

Upper Indus

Yarlung

Zangbo

Yarlung

Zangbo

Lohit

Lohit

Chenab

Chenab

MT. EVEREST

29,035 ft

8,850 m

MT. EVEREST

29,035 ft

8,850 m

Ganges

Ganges

Upper

Irrawaddy

Upper

Irrawaddy

Subansirī

Subansirī

Brahmaputra

Brahmaputra

GlacierS

by subbasin

Gain

.43

.13

0

0

5,000

feet

meters

500

1.8

.55

50

Loss

TOTAL

Glaciated Area

Square miles

MASS BALANCE

Change in water

equivalent per year,

2000-2018

Scale varies in this perspective.

Agriculture at the ‘third pole’

Regional and global food supplies depend on water from these mountains. The river basins produce 34 percent of the world’s rice (half of which is grown in the Yangtze Basin) and 17 percent of the world’s sugarcane. Both are highly water-intensive crops.

SUGARCANE

Global production, 2018

2,077 million tons

CORN

1,233

All basins

17%

10%

POTATO

28%

23%

403

WHEAT

786

34%

RICE

742

‘Towers’ release stores of water

Mountains act as natural water towers by storing and providing freshwater downstream. Each tower’s importance is ranked by determining how much water it can supply relative to downstream availability and demand; some areas, for example, have more rainfall, which can lessen their dependence on meltwater. But this source is vulnerable to climatic and economic changes.

10 million people

living in river

basin, 2015

The water tower index examines supply from glacier melt, snowmelt, rain, and surface water against downstream environmental, industrial, household, and irrigation demands.

Amu Darya

Human activities have dramatically altered natural ecosystems in the Amu Darya Basin. Extensive water diversions for irrigation from the Amu Darya and the Syr Darya contributed to the shrinking and collapse of the Aral Sea.

* includes reservoirs

Supply

Amu Darya

High

Low

Demand

Indus

The Indus Basin contains the world's largest contiguous irrigation system, one critically important to food security and water supply. But increasing demands and climate change threaten the future availability of water.

Indus

Tarim

The Tarim flows through Xinjiang, an increasingly significant cotton-growing region. The Tarim Basin produced 15 percent of the global cotton supply in 2018. Intensive agriculture is straining the basin's water resources.

Tarim

Ganges-Brahmaputra

Sacred to Hindus, the Ganges River merges with the Brahmaputra and Meghna Rivers before flowing into the Bay of Bengal. The densely populated delta is particularly susceptible to sea-level rise and coastal storms.

Ganges-Brahmaputra

Salween

The 1,700-mile Salween River remains largely free-flowing: The basin is one of the least modified in Southeast Asia. About 18 million people from more than 15 ethnic groups rely on the river basin for their livelihoods.

Salween

Yangtze

Asia's longest river flows through the Three Gorges Dam, the world's largest hydroelectric plant. The South-North Water Diversion Project could divert up to 1.7 trillion cubic feet of water a year to the Yellow River when finished.

Yangtze

Irrawaddy

The Irrawaddy River Basin is the largest in Myanmar and home to six major cities. The Chinese-financed Myitsone Dam project-approved in the 2000s and halted in 2011- remains very controversial.

Irrawaddy

Mekong

Cooperation is a challenge along the Mekong River, which winds through six countries. It's the world's second most biodiverse river and supports the largest inland fishery. Dam construction is disrupting migratory fish routes.

Mekong

Yellow

Known as the cradle of Chinese civilization, the Yellow River Basin is a key breadbasket. Demand for water outstrips supply, which diminishes discharge to the ocean. This deficit likely will be exacerbated by climate change.

Yellow

Supplement to National Geographic, July 2020

This poster was supported by Rolex, which is partnering with the National Geographic Society to shine light on the challenges facing the Earth's critical life-support systems through science, exploration, and storytelling.

Editors: Matthew W. Chwastyk, Jason Treat, and Martin Gamache

Research: Irene Berman-Vaporis and Taryn Salinas; Edward Benfield

Cartography: Eric Knight

Text: Eve Conant

Map Edit: Scott Zillmer

Design: Elaine Bradley

Sources: Arthur Lutz and Walter Immerzeel, Utrecht University; David Molden, Arun Shrestha, and Birendra Bajracharya, International Centre for Integrated Mountain Development; David Shean, University of Washington; Hester Biemans, Wageningen Environmental Reasearch; Christian Siderius, Uncharted Waters Reasearch; Stephen Darby, University of Southampton; Til Feike, Julius Kühn-Institut; Vanessa Lamb, University of Melbourne; Darrin Magee, Hobart and William Smith Colleges; Robert Nicholls, University of East Anglia; NASA, GFSAD Croplands; Landscan 2018 high-resolution population data; European Commission's Global Surface Water Explorer

MT. EVEREST

29,035 ft

8,850 m

Urban area

River basin

boundary

Cropland

Scale varies in this perspective.

Snow, ice, and rain power the rivers

Downstream populations rely heavily on mountain water. Meltwater helps regulate the seasonal pattern of river flows and boost water supply outside of the monsoon season, but climate change may weaken this buffering role. Meltwater dependence is highest in the Indus Basin.

River flow composition in the upper basins

BASE

RAINFALL

SNOWMELT

GLACIER MELT

40.6%

11.5%

15.9%

0.9%

8.3%

of flow

INDUS

Surface area of upstream basin:

163,514 square miles

BRAHMAPUTRA

142,665

GANGES

64,904

MEKONG

39,344

SALWEEN

29,344

† Flow released from groundwater

Shrinking glaciers

Many of the region’s glaciers have been losing mass since the mid-1800s, and the rate of ice loss is increasing. They shed 19 gigatons of ice each year from 2000 to 2018, with glaciers in the Brahmaputra, Indus, and Ganges Basins seeing the greatest declines.

Kaidu

Kaidu

Aksu

Aksu

Kashgar

Kashgar

Qarqan

Qarqan

Vakhsh

Vakhsh

Keriya

Keriya

Yarkant

Yarkant

Upper Yellow

Upper Yellow

Zarafshon

Zarafshon

Tongtian-Yangtze

Tongtian-Yangtze

Hotan

Hotan

Nu-Salween

Nu-Salween

Sherabod

Sherabod

Shyok

Shyok

Gilgit

Gilgit

Upper Indus

Upper Indus

Kunaṟ

Kunaṟ

Yarlung

Zangbo

Yarlung

Zangbo

Lohit

Lohit

MT. EVEREST

29,035 ft

8,850 m

Chenab

Chenab

Upper

Irrawaddy

Upper

Irrawaddy

Ganges

Ganges

Subansirī

Subansirī

Brahmaputra

Brahmaputra

Gain

GlacierS

by subbasin

.43

.13

0

0

5,000

feet

meters

500

1.8

.55

50

Loss

TOTAL

Glaciated Area

Square miles

MASS BALANCE

Change in water

equivalent per year,

2000-2018

Scale varies in this perspective.

Agriculture at the ‘third pole’

Regional and global food supplies depend on water from these mountains. The river basins produce 34 percent of the world’s rice (half of which is grown in the Yangtze Basin) and 17 percent of the world’s sugarcane. Both are highly water-intensive crops.

SUGARCANE

Global production, 2018

2,077 million tons

CORN

1,233

All basins

17%

10%

POTATO

28%

23%

403

WHEAT

786

34%

RICE

742

‘Towers’ release stores of water

Mountains act as natural water towers by storing and providing freshwater downstream. Each tower’s importance is ranked by determining how much water it can supply relative to downstream availability and demand; some areas, for example, have more rainfall, which can lessen their dependence on meltwater. But this source is vulnerable to climatic and economic changes.

10 million people

living in river

basin, 2015

The water tower index examines supply from glacier melt, snowmelt, rain, and surface water against downstream environmental, industrial, household, and irrigation demands.

Amu Darya

Human activities have dramatically altered natural ecosystems in the Amu Darya Basin. Extensive water diversions for irrigation from the Amu Darya and the Syr Darya contributed to the shrinking and collapse of the Aral Sea.

* includes reservoirs

Supply

Amu Darya

High

Low

Demand

Indus

The Indus Basin contains the world's largest contiguous irrigation system, one critically important to food security and water supply. But increasing demands and climate change threaten the future availability of water.

Indus

Tarim

The Tarim flows through Xinjiang, an increasingly significant cotton-growing region. The Tarim Basin produced 15 percent of the global cotton supply in 2018. Intensive agriculture is straining the basin's water resources.

Tarim

Ganges-Brahmaputra

Sacred to Hindus, the Ganges River merges with the Brahmaputra and Meghna Rivers before flowing into the Bay of Bengal. The densely populated delta is particularly susceptible to sea-level rise and coastal storms.

Ganges-Brahmaputra

Salween

The 1,700-mile Salween River remains largely free-flowing: The basin is one of the least modified in Southeast Asia. About 18 million people from more than 15 ethnic groups rely on the river basin for their livelihoods.

Salween

Yangtze

Asia's longest river flows through the Three Gorges Dam, the world's largest hydroelectric plant. The South-North Water Diversion Project could divert up to 1.7 trillion cubic feet of water a year to the Yellow River when finished.

Yangtze

Irrawaddy

The Irrawaddy River Basin is the largest in Myanmar and home to six major cities. The Chinese-financed Myitsone Dam project-approved in the 2000s and halted in 2011- remains very controversial.

Irrawaddy

Mekong

Cooperation is a challenge along the Mekong River, which winds through six countries. It's the world's second most biodiverse river and supports the largest inland fishery. Dam construction is disrupting migratory fish routes.

Mekong

Yellow

Known as the cradle of Chinese civilization, the Yellow River Basin is a key breadbasket. Demand for water outstrips supply, which diminishes discharge to the ocean. This deficit likely will be exacerbated by climate change.

Yellow

Supplement to National Geographic, July 2020

This poster was supported by Rolex, which is partnering with the National Geographic Society to shine light on the challenges facing the Earth's critical life-support systems through science, exploration, and storytelling.

Editors: Matthew W. Chwastyk, Jason Treat, and Martin Gamache

Research: Irene Berman-Vaporis and Taryn Salinas; Edward Benfield

Cartography: Eric Knight

Text: Eve Conant

Map Edit: Scott Zillmer

Design: Elaine Bradley

Sources: Arthur Lutz and Walter Immerzeel, Utrecht University; David Molden, Arun Shrestha, and Birendra Bajracharya, International Centre for Integrated Mountain Development; David Shean, University of Washington; Hester Biemans, Wageningen Environmental Reasearch; Christian Siderius, Uncharted Waters Reasearch; Stephen Darby, University of Southampton; Til Feike, Julius Kühn-Institut; Vanessa Lamb, University of Melbourne; Darrin Magee, Hobart and William Smith Colleges; Robert Nicholls, University of East Anglia; NASA, GFSAD Croplands; Landscan 2018 high-resolution population data; European Commission's Global Surface Water Explorer

MT. EVEREST

29,035 ft

8,850 m

Urban area

River basin

boundary

Cropland

Scale varies in this perspective.

Snow, ice, and rain power the rivers

Downstream populations rely heavily on mountain water. Meltwater helps regulate the seasonal pattern of river flows and boost water supply outside of the monsoon season, but climate change may weaken this buffering role. Meltwater dependence is highest in the Indus Basin.

River flow composition in the upper basins

BASE

RAINFALL

SNOWMELT

GLACIER MELT

40.6%

11.5%

15.9%

0.9%

8.3%

of flow

INDUS

Surface area of upstream basin:

163,514 square miles

BRAHMAPUTRA

142,665

GANGES

64,904

MEKONG

39,344

SALWEEN

29,344

† Flow released from groundwater

Shrinking glaciers

Many of the region’s glaciers have been losing mass since the mid-1800s, and the rate of ice loss is increasing. They shed 19 gigatons of ice each year from 2000 to 2018, with glaciers in the Brahmaputra, Indus, and Ganges Basins seeing the greatest declines.

Kaidu

Aksu

Kashgar

Vakhsh

Qarqan

Yarkant

Upper Yellow

Keriya

Zarafshon

Amu Darya

Tongtian-Yangtze

Sherabod

Hotan

Nu-Salween

Gilgit

Shyok

Upper

Indus

Kunaṟ

Yarlung Zangbo

Lohit

Chenab

MT. EVEREST

29,035 ft

8,850 m

Ganges

Subansirī

Upper

Irrawaddy

Brahmaputra

GlacierS

by subbasin

Gain

.43

.13

0

0

5,000

feet

meters

500

1.8

.55

50

Loss

TOTAL

Glaciated Area

Square miles

MASS BALANCE

Change in water

equivalent per year,

2000-2018

Scale varies in this perspective.

Agriculture at the ‘third pole’

Regional and global food supplies depend on water from these mountains. The river basins produce 34 percent of the world’s rice (half of which is grown in the Yangtze Basin) and 17 percent of the world’s sugarcane. Both are highly water-intensive crops.

SUGARCANE

Global production, 2018

2,077 million tons

CORN

1,233

All basins

17%

10%

POTATO

28%

23%

403

WHEAT

786

34%

RICE

742

‘Towers’ release stores of water

Mountains act as natural water towers by storing and providing freshwater downstream. Each tower’s importance is ranked by determining how much water it can supply relative to downstream availability and demand; some areas, for example, have more rainfall, which can lessen their dependence on meltwater. But this source is vulnerable to climatic and economic changes.

10 million people

living in river

basin, 2015

The water tower index examines supply from glacier melt, snowmelt, rain, and surface water against downstream environmental, industrial, household,

and irrigation demands.

Amu Darya

Amu Darya

Human activities have dramatically altered natural ecosystems in the Amu Darya Basin. Extensive water diversions for irrigation from the Amu Darya and the Syr Darya contributed to the shrinking and collapse of the Aral Sea.

Supply

index

High

Low

Demand

index

* includes reservoirs

Indus

The Indus Basin contains the world's largest contiguous irrigation system, one critically important to food security and water supply. But increasing demands and climate change threaten the future availability of water.

Indus

Tarim

The Tarim flows through Xinjiang, an increasingly significant cotton-growing region. The Tarim Basin produced 15 percent of the global cotton supply in 2018. Intensive agriculture is straining the basin's water resources.

Tarim

Ganges-Brahmaputra

Sacred to Hindus, the Ganges River merges with the Brahmaputra and Meghna Rivers before flowing into the Bay of Bengal. The densely populated delta is particularly susceptible to sea-level rise and coastal storms.

Ganges-Brahmaputra

Salween

The 1,700-mile Salween River remains largely free-flowing: The basin is one of the least modified in Southeast Asia. About 18 million people from more than 15 ethnic groups rely on the river basin for their livelihoods.

Salween

Yangtze

Yangtze

Asia’s longest river flows through the Three Gorges Dam, the world’s largest hydroelectric plant. The South-North Water Diversion Project could divert up to 1.7 trillion cubic feet of water a year to the Yellow River when finished.

Irrawaddy

The Irrawaddy River Basin is the largest

in Myanmar and home to six major cities. The Chinese-financed Myitsone Dam project—approved in the 2000s and halted in 2011—remains very controversial.

Irrawaddy

Mekong

Cooperation is a challenge along the Mekong River, which winds through six countries. It's the world's second most biodiverse river and supports the largest inland fishery. Dam construction is disrupting migratory fish routes.

Mekong

Yellow

Known as the cradle of Chinese civilization, the Yellow River Basin is a key breadbasket. Demand for water outstrips supply, which diminishes discharge to the ocean. This deficit likely will be exacerbated by climate change.

Yellow

Supplement to National Geographic, July 2020

This poster was supported by Rolex, which is partnering with the National Geographic Society to shine light on the challenges facing the Earth's critical life-support systems through science, exploration, and storytelling.

Editors: Matthew W. Chwastyk, Jason Treat, and Martin Gamache

Research: Irene Berman-Vaporis and Taryn Salinas; Edward Benfield

Cartography: Eric Knight

Text: Eve Conant

Map Edit: Scott Zillmer

Design: Elaine Bradley

Sources: Arthur Lutz and Walter Immerzeel, Utrecht University; David Molden, Arun Shrestha, and Birendra Bajracharya, International Centre for Integrated Mountain Development; David Shean, University of Washington; Hester Biemans, Wageningen Environmental Reasearch; Christian Siderius, Uncharted Waters Reasearch; Stephen Darby, University of Southampton; Til Feike, Julius Kühn-Institut; Vanessa Lamb, University of Melbourne; Darrin Magee, Hobart and William Smith Colleges; Robert Nicholls, University of East Anglia; NASA, GFSAD Croplands; Landscan 2018 high-resolution population data; European Commission's Global Surface Water Explorer