Watersheds Around

The World

Nathan ChenStuart Guan

What is a watershed?• An area

of land that separates water flow to different rivers, basins, or seas

Major Watersheds

North and Central America

South America

Africa

Europe

Asia and Oceania

North and

Central America

• 847,620 sq. km –23%Yukon

• 1,706,388 sq. km –7%Mackenzie

• 239,245 sq. km –0%Thelon

• 248,016 sq. km –7%Fraser

• 1,093,141 sq. km –21%Nelson

• 657,501 sq. km –22%Columbia

• 78,757 sq. km –26%Sacramento

• 3,202,185 sq. km –52%Mississippi

• 703,148 sq. km –43%Colorado

• 1,049,636 sq. km –31%Saint Lawrence

• 78,672 sq. km –14%Susquehanna

• 41,906 sq. km –9%Hudson

• 138,139 sq. km –25%Alabama and Tombigbee

• 137,098 sq. km –81%Brazos

• 607,955 sq. km –52%Rio Grande

• 136,694 sq. km –52%Rio Grande de Santiago

• 79,162 sq. km –16%Yaqui

• 117,095 sq. km - 29%Balsas

• 78,720 sq. km - 37%San Pedro & Usamacinta

Loss of Original Forest Cover

Mississippi Basin• Watershed encompasses 40%

of the U.S.• The Mississippi River is the

largest and longest in terms of discharge (Average 17,330 m3/sec)

• World’s second largest basin• Greatest concern today is “The

Dead Zone”• The problem is nutrient load

generated less oxygen• Possible solutions include

improved farm management and restoration of forest and wetlands removing the excess nutrients.

South America

Magdalena – 10,191

Orinoco – 90,482

Amazon – 273,767

Tocantins – 103,383

Parnaiba – 7,729

Sao Francisco – 8,261

Parana – 8,025

Uruguay – 32,731

Lake Titicaca and Salar de Uyuni – 15,980

Rio Colorado – 3,196

Chubut – 171,362

Water Supply per Person (m3/person/year)

Amazon Basin• Contains 1/5 of the

worlds fresh water• Flows 12 times faster

than Mississippi River• Tropical Rain Forest

supplies over half of the planet’s oxygen

• High point in the watershed (the peak of Yerupajá)[6,635 m]

• Water flows from Pacific Ocean forming the Andes to the Atlantic Ocean

• Outstanding Animal life > 5,000 species

Africa

Ou

ed

Dra

a –

1

0S

en

eg

al –

10

Nig

er

– 31

Lake

Chad

–

11

Nile

– 4

6

Volt

a –

43

Con

go –

15

Ora

ng

e –

10

Jub

ba –

12

Sh

ab

alle

–

29

Og

oou

e –

2

Cu

an

za –

23

Ru

fiji

– 2

1

Zam

bezi

–

18

Oka

van

go –

2

Lim

pop

o –

3

2M

on

goky

–

18

Man

ia –

25

Lake

Turk

ana –

61

Average Population Density (people per sq. km)

Turkana Basin• Northern Kenya and Southern

Ethiopia• Lake Turkana supports the wildlife

and locals• Ineffective drainage becoming an

arid scrubland• Increased evolutionary plant life of

C4 plants• Most sensitive area to temperature

and influx of weather• No transboundary agreement with

the other larger basin nearby stressing Lake Turkana

• Area – the cradle of mankind

Europe

1 – Duero

2 – Kizilirmak

29 – Guadalquivir31 – Kemijoki,

Glomma-Laagen, and Eboro

33 - North Dvina

39 – Seine, Tagus

40 - Lake Ladoga, Garonne

41 – Dalalven

43 – Loire

44 – Oder

47 – Po, Kura-Araks

48 – Ural, Weser

49 – Don

50 - West Dvina, Dnieper

51 - Elbe

57 – Nistru

58 – Rhone

59 – Vistula

60 - Rhine-Maas

88 – Volga

92 - Tigris & Euphrates

Number of Fish Species

Tigris & Euphrates Basin• Monstrous fish weighing as

much as 300 lbs• Economic life dependent on

the rivers and the oil revenues of Iraq

• Lots of desiccated marshland and soil nutrient depletion

• Lack of international agreement Turkey’s dams reduced water flow into Iraq

• Tensions run high on water management

• GAP project (22 dams and 19 hydropower plant) split

Asia and Oceania

0%• Pechora, Yenisey, Lena, Indigirka, Kolyma,

Kapuas, Mahakam, Fly, Sepik

0%-1%• Ob, Tarim,

Amur, Salween

1%-5%• Lake Balkhash, Yalu Jiang, Brahmaputra, Mekong, Irrawaddy,

Red River, Burdekin-Belyando, Dawson, Murray-Darling

5%-10%

• Syr Darya, Amu Darya, Pearl River, Yangtze, Yellow River

10%-15%

• Tapti, Godavari

15%-20% • Mahanadi, Krishna

20%-25%

• Indus, Ganges, Narmada

Percent Irrigated Cropland

Yangtze Basin

• Area = 1.81 million sq. km

• Food staple of China – Rice for 1.3 billion people

• Fertile soil highly favorable to agriculture

• Contributes to > half of China’s crop production (2/3) is rice

• Severe droughts and irregular rainfall result in crop loss

• Solution - modern irrigation projects like the Three Gorges Project

Web Sources•  http://www.unep.org/pdf/UNEP_GEAS_JUNE_2013.pdf• http://news.mongabay.com/2006/1024-amazon.html• http://news.nationalgeographic.com/news/2007/06/070619-amazon-river.html• http://global.britannica.com/EBchecked/topic/18722/Amazon-River• http://multimedia.wri.org/watersheds_2003/index.html• http://www.waterencyclopedia.com/Mi-Oc/Mississippi-River-Basin.html• http://www.academia.edu/7277108/Variations_in_water_level_for_Lake_Turkan

a_in_the_past_8500_years_near_Mt._Porr_Kenya_and_the_transition_from_the_African_Humid_Period_to_Holocene_aridity._Quaternary_Science_Reviews_97_84-101

• http://www.futuredirections.org.au/publications/food-and-water-crises/678-water-shortage-crisis-escalating-in-the-tigris-euphrates-basin.html

• http://www.britannica.com/EBchecked/topic/651857/Yangtze-River/48044/People

• http://www.eoearth.org/view/article/173855/