South AsiaSouth Asia

U N I T

FPO88

554 U n i t 8

U n i t 8 555

WHY IT’S IMPORTANT—

Many of the countries of South Asia

have earned their independence rela-

tively recently, but they have their roots

in very ancient civilizations.The rich cul-

ture, minerals, and spices of the area

have attracted foreign invaders for hun-

dreds of years. Since the subcontinent

shook off the cloak of British colonial

rule in the 20th century, political and reli-

gious rivalries within the region have

threatened its peace and stability.The

governments of South Asia are strug-

gling to overcome their differences and

increase the region’s role in trade and

technological development.

To learn more about South Asia

and its impact on your world, view

the World Regions video “South Asia.”

Monk in front of dome of Buddhist shrine, Nepal

World Regions Video

NGS ONLINEwww.nationalgeographic.com/education

Like a giant pointed tooth, South Asia juts out of the Asian continentand into the salty waters of the Arabian Sea, the Indian Ocean, andthe Bay of Bengal.Towering mountains separate this region fromthe rest of Asia.The greatest of these are the mountains of the

Himalaya, which include Mount Everest—the tallest peak on Earth.South of the Himalaya, the land descends to fertile lowlands that

are watered by the Indus, Brahmaputra, and Ganges River systems. SouthAsia’s southern tip is outlined by the Eastern andWestern Ghats, ranges of low mountains that frame an arid tableland called the Deccan Plateau.

From snowy highlands to sun-scorched deserts,South Asia has a variety of climate zones.The climate is greatly affected by monsoons—seasonal winds thatbring cycles of wet and dry weather to the region.

What Makes South Asia a Region?

1 Bright bridles and nose ringsadorn a camel in the Thar, orGreat Indian, Desert. Straddlingnorthwestern India and easternPakistan, the desert lies beyondthe reach of heavy monsoonrains. Camels are a traditionalmeans of transportation in thisarid part of South Asia.

3

1

2

U N I TREGIONAL ATLAS8

556 U n i t 8

Water swirls down a street in Delhi during India’s wetmonsoon season. Each year as summer approaches, windpatterns shift and moist air fromthe Indian Ocean sweeps overthe subcontinent. Once therains begin, they may continuefor 60 days or more.

Up to their knees in greenshoots, a farmer and his cow pause in a paddy inBangladesh. The rich soil of the Ganges River delta spreadsacross much of Bangladesh,helping to make this tiny coun-try one of the world’s leadingproducers of rice.

Whitewashed walls echo thebrilliance of snow-coveredpeaks in Namche Bazaar, a Sherpa village in Nepal.Sherpas are a people who livemainly among the mountainsof the Himalaya, where theyhave won fame as guides onclimbing expeditions.

2 3 4

4

U n i t 8 557

U N I TREGIONAL ATLAS

Population Giant

Red powder coats the face of an Indian boy during thefestival of Ganesh Chaturthi.The festival celebrates the birthof Ganesh, an elephant-headedHindu god. Hinduism is themost widespread religion inSouth Asia today.

12

3

8

558 U n i t 8

Over the centuries, the fertile floodplains of the Indusand Ganges Rivers have attracted many immigrants andinvaders to South Asia, giving the region great diversityin peoples, languages, customs, and religious beliefs.

Hinduism and Buddhism both originated in South Asia, whereas Islam arrived fromthe west.The British brought colonialrule,which lasted for nearly two centuries.The region won its independence in the mid-1900s, but not without political,religious, and economic upheaval.

South Asia remains culturally rich, butits burgeoning population—over one bil-lion in India alone—struggles with a lowstandard of living. Subsistence farmingand labor-intensive traditional industriesform the basis of the region’s economy.

Mirrored in still water, the TajMahal stands serenely outsidethe city of Agra, in northernIndia. The Taj Mahal was built inthe 1600s by a Muslim ruler asa tomb for his favorite wife.Constructed of white marble,the building is decorated withverses from the Quran, the holybook of Islam.

Filled to overflowing, a gailypainted city bus takes on passengers in a crowded street in Dhaka, the capital ofBangladesh. With a populationof about 134 million, Bangladeshis one of the most denselypopulated countries in theworld—and also one of thepoorest and least developed.

Tender tea leaves are pluckedby hand on a plantation in Sri Lanka, formerly calledCeylon. A legacy of British colonial rule, plantations producemuch of the famous Ceylon teathat is a major product of thisisland nation. Sri Lanka gainedits independence from Britainin 1948.

2 3 4

4

South Asia

PHYSICAL

N

Mt. Everest29,035 ft.(8,850 m)

K2 (Godwin Austen)28,250 ft.(8,611 m)

EA

ST

ER

N

G HA T S

WE

ST

ER

NG

HA

TS

D E C C A N

P L A T E A U

HI

MA

LA Y A

HINDU KUSH

Great IndianDesert

Dondra Head

CapeComorin

Lakshadweep

AndamanIslands

NicobarIslands

Rann ofKutch

KathiawarPeninsula

CentralMakranRange

SulaimanRange

KhyberPass

Vindhya Range

Satpura Range

KarakoramRange

GA

NG E S

P L A I NChota Nagpur

Plateau

MizoHills

Nag

aHill

s

Khasi Hills

Arav

alli

Ra

nge

Ma l a b

a rC

o a s t

Coro

man

delC

oast

.R

sudnI

Ganges R.

Narmada R.

BrahmaputraR.

Ganges RiverDelta

Godavari R.

Krishna R.

Sutlej R.

Yamuna R.

Ghaghara R.

Cha

mba

l R.

Mahanadi R.

Arabian

SeaBay of

Bengal

Palk Strait

TROPIC OF CANCER

60°E

30°N

20°N

10°N

70°E 80°E

90°E

I N D I A

PAKISTAN

BANGLADESH

BHUTANN E P A L

SRI LANKAMALDIVES

E A S T

A S I AC E N T R A L

A S I A

Lambert Azimuthal Equal-Area projection400

4000

0

mi.

km

Elevation Profile

0 mi.

0 km 500

500

Sea level

2,000 m

4,000 m

6,000 m

8,000 m

6,562 ft

13,123 ft

19,685 ft

26,247 ft

BRAHMAPUTRA RIVER

INDUSRIVER

GREATINDIANDESERT GANGES

PLAIN

MT. EVEREST

HIMALAYA

U N I TREGIONAL ATLAS8

560 U n i t 8

POLITICAL60°E

30°N

20°N

10°N

70°E 80°E 90°E

TROPIC OF CANCER

Arabian

Sea

Bay of

Bengal

.R

sudnI

.RsegnaG

Sutlej R.

Godavari R.

K rishna R.

.RadamraN

.RartupamharB

EA

ST

ER

N

G

HA

TS

WE

ST

ER

NG

HA

TS

DECCANPLATEAU

GANGES PLAIN

HI

M

AL

AY

A

HINDU KUSH

GREAT

IND

IAN

DESERT

Lakshadweep

Islamabad

Lahore

Ludhiana

KathmanduLucknow

Pune

New DelhiDelhi

Jaipur

Faisalabad

Chittagong

Bangalore

Mumbai(Bombay)

Thimphu

Kanpur

Karachi

Ahmadabad

Hyderabad

Chennai(Madras)

Kolkata(Calcutta)

Dhaka

Colombo

Indore Bhopal

Surat Nagpur

Khulna

Male

AndamanIslands

NicobarIslands

Ind.

Ind.

Ind.

I N D I A

PAKISTAN

BANGLADESH

BHUTAN

SRILANKA

MALDIVES

NEPAL

C E N T R A L

A S I AE A S T

A S I A

Lambert Azimuthal Equal-Area projection400

4000

0

mi.

km

N

U n i t 8 561

National capitalMajor city

1. Which capital city in South Asia do youthink has the highest elevation?

2. What rivers join to form the Ganges River delta?

StudyMAP

POPULATION DENSITY60°E

30°N

20°N

10°N

70°E 80°E

90°E

TROPIC OF CANCER

Indian Ocean

Arabian

Sea

Bay of

Bengal

NicobarIslands

AndamanIslandsLakshadw

eep

Ind.

Ind.

Ind

.

Dhaka

Colombo

Cochin

Chittagong

Patna

Mumbai(Bombay)

Bangalore Chennai(Madras)

Kolkata(Calcutta)

Jaffna

Hyderabad

Pune

Delhi

Karachi

Lahore

KanpurLucknow

Islamabad

Quetta

ThimphuKathmandu

IndoreBhopal

Multan

Vadodara

Nagpur

Ahmadabad

Jaipur Agra

Mysore

Kozhikode(Calicut)

Peshawar

Khulna

Rawalpindi

C E N T R A L

A S I AE A S T

A S I A

Lambert Azimuthal Equal-Area projection400

4000

0

mi.

km

N

South Asia

U N I TREGIONAL ATLAS8

562 U n i t 8

Cities(Statistics reflect metropolitan areas.)

Per sq. mi.Per sq. kmOver 100

50–100

25–50

1–25

Under 1

Uninhabited

Over 250

125–250

60–125

2–60

Under 2

Uninhabited

Over 5,000,000

2,000,000–5,000,000

1,000,000–2,000,000

250,000–1,000,000

Under 250,000

ECONOMIC ACTIVITY

60°E

30°N

20°N

10°N

70°E 80°E 90°E

TROPIC OF CANCER

Arabian

Sea

Bay of

Bengal

Dhaka

Colombo

Karachi

Chittagong

Mumbai(Bombay)

BangaloreChennai(Madras)

Hyderabad

Pune

Kolkata (Calcutta)

Delhi

Lahore

Rawalpindi

Kanpur

Lucknow

Patna

AndamanIslands

Lakshadweep

Nicobar Is.

Tea

Tea

Cotton

Coconuts

Coconuts

Rice

Cotton

Cotton

Cattle

Cattle

Cattle

Wheat

Sheep

Corn

Cotton

WheatWheat

Sheep

Sheep

GoatsRice

Jute

Jute

Barley

Rice

Rice

Rice

Rubber

Pearls

I N D I A

PAKISTAN

BANGLADESH

BHUTAN

SRI LANKAMALDIVES

NEPAL

C E N T R A L

A S I AE A S T

A S I A

Lambert Azimuthal Equal-Area projection400

4000

0

mi.

km

N

U n i t 8 563

Resources

Petroleum

Natural gas

Coal

Uranium

Iron ore

Chromite

Gemstones

Copper

Land UseCommercial farmingSubsistence farmingNomadic herdingHunting and gatheringForestsManufacturing and tradeCommercial fishingLittle or no activity

1. What is the predominant land usein South Asia?

2. In which areas of South Asia is population density the highest?

StudyMAP

Taka

Ngultrum

Rupee

ConstitutionalMonarchy

Republic

Federal Republic

133,500,0002,401 per sq. mi.927 per sq. km

55,598 sq. mi.143,998 sq. km

900,00050 per sq. mi.19 per sq. km

1,033,000,000814 per sq. mi.314 per sq. km

18,147 sq. mi.47,001 sq. km

1,269,340 sq. mi.3,287,606 sq. km

Bengali

Gems & Jewelry

Dzonkha, Local Languages

MaldivianRufiyaa Republic

300,0002,495 per sq. mi.963 per sq. km

116 sq. mi.300 sq. km

Maldivian Divehi,English

Hindi, English,Local Languages

Machinery

Fuels

Clothing

MachineryFish

NepaleseRupee

PakistanRupee

Sri LankaRupee

Constitutional Monarchy

Federal Republic

Republic

23,500,000413 per sq. mi.159 per sq. km

19,500,000771 per sq. mi.298 per sq. km

56,826 sq. mi.147,179 sq. km

25,332 sq. mi.65,610 sq. km

Sinhalese, Tamil, English

Nepali

145,000,000472 per sq. mi.182 per sq. km

307,375 sq. mi.796,101 sq. km

Urdu, English,Punjabi, Sindhi Cotton

Machinery

Petroleum

Clothing

Textiles

INDIA

New Delhi

BANGLADESH

Dhaka

BHUTAN

Thimphu

MALDIVES

Male

PAKISTANIslamabad

Colombo

NEPAL

Kathmandu

SRI LANKA

Cardamom

Crude Oil

PetroleumProducts

charge card

123456789

COUNTRY *

AND CAPITAL

FLAG AND

LANGUAGE

POPULATION

AND DENSITYLANDMASS

MAJOR

EXPORT

MAJOR

IMPORTCURRENCY GOVERNMENT

COUNTRY PROFILES

* COUNTRIES AND FLAGS NOT DRAWN TO SCALE

FOR AN ONLINE UPDATE OF THIS INFORMATION, VISIT GEOGRAPHY.GLENCOE.COM AND CLICK ON “TEXTBOOK UPDATES.”

▲

Boarding school students in Nepalganj, Nepal, study a computer.

South Asia

U N I TREGIONAL ATLAS8

564 U n i t 8

U n i t 8 565

There are few things more comfortable than a pair of well-wornblue jeans. Denim—that soft, strong cotton fabric with the richblue color—has become an integral part of modern life. But“indigo-dyed” textiles are nothing new—they were being

produced in India many centuries ago. In fact, the word indigo comes from the name “India”!

South Asia has been a world center of textile production for thousands of years. As long ago as 2700 B.C.,people in the Indus River valley were cultivating cotton plants and weavingcotton fibers into cloth. AncientIndian artisans elevated spinningand weaving to art forms.Theywere among the first in theworld to master techniques fordyeing cotton and other typesof fabric. Using extracts frommore than 300 different nativeplants, along with other naturalsubstances, the artisans createdbeautiful, brilliant fabric dyes.The dark blue dye known as indigo, for example, came from the indigo plant.

Indian textile makers pioneeredanother important technique—making dyes

TEXTILES ▲ Freshly printed fabric dryingin Jodhpur, India

�

GLOBALCONNECTION

SOUTH ASIA AND THE UNITED STATES

U N I TREGIONAL ATLAS8

566 U n i t 8

permanent, or “colorfast,” so they would not wash out.The colorfastnessof Indian fabrics, combined with their vivid colors and intricate wovenand printed patterns, made these fabrics highly prized in Europe,Asia, andother regions. By the 1700s, India was the greatest exporter of textiles theworld had ever known.

In England, printed Indian fabrics known as calico and chintz became wildly popularfor both fashions and furnishings. Eventually, such fabrics made their way to theAmerican colonies. So precious were these imported textiles that scraps of calico and

chintz were saved and made into patchwork quilts—a thrifty gesture that wouldeventually become an American craft tradition.

Fabrics and patterns that originated in South Asia are now made in other places.However, India is still one of the world’s leading producers of cotton, and thetextile industry remains India’s most important industry. India’s eastern neighbor,Bangladesh, also has a thriving garment industry. Check the labels in your cottonclothes—chances are some were made in South Asian countries.

▲ Colorful dyes for sale on a street stand in Bangalore, India

Indian woman spinning cotton thread▲

U n i t 8 567

GeoJournalAs you read this chapter, use your journal torecord the geographic features of the coun-tries of South Asia. Use descriptive terms tocontrast the mountains, deserts, plains, andrivers of South Asia.

Chapter Overview Visit the Glencoe WorldGeography Web site at tx.geography.glencoe.comand click on Chapter Overviews—Chapter 23 to preview information about the physicalgeography of the region.

The Land

A Geographic ViewIndia by TrainThe valleys and these hillsides [in the north of India] are open to thedistant plains, and so the traveleron the toy train has a view thatseems almost unnatural, it is sodramatic. At Sonada it is likestanding at the heights of agigantic outdoor amphitheaterand looking down and seeing the plains and the rivers, roads and crops printed upon it and flattened by the yellow heat.

—Paul Theroux, “By Rail Across the Indian Subcontinent,”National Geographic, June 1984

Novelist Paul Theroux described the varied anddramatic landscapes he saw while traveling South Asia by train. Inthis section you will explore the physical geography of South Asia—its majestic mountains, mighty rivers, and fertile plains.

A Separate LandThe seven countries that make up South Asia are separated from

the rest of Asia by mountains. As a result, South Asia is called asubcontinent, a large, distinct landmass that is joined to a continent.In geologic terms South Asia contains some of the oldest and some ofthe youngest landforms on Earth.

Most of South Asia forms a peninsula of about 1.7 million square miles(4.4 million sq. km) touched by three bodies of water—the Arabian Seato the west, the Indian Ocean to the south, and the Bay of Bengal to theeast. The region also includes many small islands and the large islandcountry of Sri Lanka, which lies off India’s southern tip.

Guide to ReadingConsider What You KnowMount Everest in the Himalaya is theworld’s highest peak. You may oftenread or hear reports of climbers on Mount Everest and the difficultiesthey face. What features of highmountain ranges do you think con-tribute to the climbers’ hardships?

Read to Find Out• What landforms exist in

South Asia?

• What are the three great river systems on which life in SouthAsia depends?

• How do the peoples of South Asia use the region’s naturalresources?

Terms to Know• subcontinent

• alluvial plain

• mica

Places to Locate• Himalaya

• Ganges Plain

• Vindhya Range

• Deccan Plateau

• Indus River

• Brahmaputra River

• Ganges River

C h a p t e r 2 3 569

Buddhist monastery in Bhutan

Train passing through Himalayan foothills

Other Northern LandformsThe Himalaya meet the Karakoram Mountains

in the northernmost part of South Asia. Fartherwest, the Hindu Kush range completes the chain.Together, they create a high wall of mountainsbetween the subcontinent and the rest of Asia. In thepast, invaders from the north could only enter theregion through a few narrow crossing places, suchas the famous Khyber Pass between Pakistan andAfghanistan. The Himalaya also protected Nepaland Bhutan from outside influence until the 1900s.

At the foot of the Himalaya ranges, wide fer-tile plains are watered by the region’s greatrivers—the Indus, the Ganges (GAN•JEEZ), andthe Brahmaputra. One-tenth of the world’s peoplelive in this crowded northern area referred to asthe Ganges Plain (or Indo-Gangetic Plain). In thenortheast of India lies the Chota Nogpur Plateau,a high tableland of forests.

Culture

Central LandformsThe collision between the Indian subcontinent

and Asia also pushed up a mountain range in cen-tral India. Not as tall as the Himalaya, the VindhyaRange divides India into northern and southernregions. This physical division separates the twodistinct cultures that have developed in India. Thecuisine, architecture, and religious practices of thepeoples of northern and southern India differmarkedly, as you will read in the next chapter.

Southern LandformsThe southern regions of South Asia contrast with

those of the north. At the base of the subcontinent,two chains of eroded mountains—the Eastern

South Asia is about half the size of thecontinentalUnited States.

Fierce winds blow Buddhist prayer flags in Nepal.

A Land of Great VarietySouth Asia reveals a varied landscape. In the far

north, some of the world’s highest mountain rangesraise sharp, icy peaks above terraced foothills, highdesert plateaus, and rich valleys. The older southernlands include eroded mountains and flat plateaus.

The HimalayaAccording to the theory of continental drift,

about 60 million years ago the Indian subcontinentwas part of the same large landmass as Africa.After the subcontinent broke away, it collided withthe southern edge of Asia. The force of this colli-sion thrust up new mountain ranges, theHimalaya. These ranges spread more than 1,000miles (1,609 km) across the northern edge of thepeninsula and are hundreds of miles wide. MountEverest, the world’s highest peak, rises to 29,035feet (8,850 m) above sea level in the Himalaya. Ateenager describes climbing in the Himalaya:

“ . . . I’m standing alone on a portion ofthe summit. . . . On very clear days likethis, some from Everest have claimed tosee the curvature of the earth ; otherssay they can see the Indian Ocean, hun-dreds of miles away. . . . [I]t makes mefeel very small. . . .”Mark Phetzer, Within Reach:

My Everest Story, 1998

C h a p t e r 2 3 571

Ghats and Western Ghats—form a triangle ofrugged hills. Between them lies the DeccanPlateau. This plateau was part of the landmassfrom which the subcontinent broke away and ishundreds of millions of years old. Once coveredwith lava, the Deccan Plateau today has rich, blacksoil. The Western Ghats, however, prevent yearlyrainy winds from reaching the plateau, leaving itarid, or extremely dry. The Karnataka Plateausouth of the Deccan Plateau receives these rainsinstead, so hills there are lush and green. Spices

growing on plantations in this area scent the air,and wild elephants move through the foliage ofthe plateau’s dense rain forests.

Sri Lanka (SREE LAHN•kuh) is a teardrop-shaped island that broke away from the originalIndian landmass. Maldives (MAWL•DEEVZ), thesouthernmost country in South Asia, is a chainof tiny coral atolls and volcanic outcroppings.Although Maldives covers 38,000 square miles(98,420 sq. km) of ocean, its land area totals only115 square miles (298 sq. km).

ArabianSea

Bay ofBengal

I n d i a n O c e a n

Ganges R. Brahmaputra

R.

Sutlej R.

Narmada R.

Krishna R.

Godavari R .

Indus

R.

Mt. Everest29,035 ft.(8,850 m)

K2 (Godwin Austen)28,250 ft.(8,611 m)

I N D I A

PAKISTAN

BANGLADESH

BHUTAN

SRI LANKA

MALDIVES

NEPAL

H

I

M

A

LA

YA

Kashmir

Ganges Plain

Chota Nagpur

Plateau

GREAT INDIAN

DESERT

Deccan

Plateau

WE

ST

ER

NG

HA

TS

EA

ST

ER

N

GH

A

TS

Andaman

Islands

Lakshadweep

Nicobar

Islands

HIN

DU

KU

SH

Khyber

Pass

VINDHYA RANGE

Karnataka

Plateau

10°N

20°N

30°N

40°N

70°E 80°E 90°E 100°E

TROPIC OF CANCER

Lambert AzimuthalEqual-Area projection

400

4000 mi.

0 km

N

MAP STUDY

South Asia: Physical-Political

Find NGS online map resources @www.nationalgeographic.com/maps

National boundaryMountain peak

Feet10,000

5,0002,0001,000

0

MetersElevations

3,0001,500

600300

0

1. Interpreting Maps Whatranges extend along thecoast of southern India?

2. Applying GeographySkills Why does most ofSouth Asia’s population liveon the northern plains?

Major River SystemsRivers are the key to life in South Asia. From

sources high in the Himalaya, three major riversystems—the Indus, the Brahmaputra, and theGanges—fan out across the northern part of theIndian subcontinent. All three rivers carry fertilesoil from mountain slopes onto their floodplainsas the rivers swell with seasonal rains.

Indus and Brahmaputra RiversThe Indus River flows mainly through Pakistan,

watering orchards of peaches and apples beforeemptying into the Arabian Sea. It also serves as animportant transportation route. Historically, theIndus River valley is known as the cradle ofancient India, which, with Mesopotamia andEgypt, was one of the world’s earliest civilizations.

The Brahmaputra River flows east through theHimalaya and then west into India and Bangladesh.There it joins the Ganges—to form a delta beforeemptying into the Bay of Bengal. The Brahmaputrais a major inland waterway. Ships can navigate theriver from the the Bay of Bengal as far inland asDibrugarh in the Indian state of Assam, about 800miles (about 1,290 km) from the sea. The Brahma-

putra also provides Bangladesh with 50 percent ofits power through hydroelectricity.

Ganges RiverThe Ganges River flows east from the

Himalaya. It is the most important river of SouthAsia, drawing waters from a basin covering about400,000 square miles (about 1 million sq. km). Fedby water from snowcapped peaks, the Gangesretains its size throughout the year, even during thehot, dry season from April to June. During thesummer monsoon period, heavy rains can causedevastating floods along the Ganges. Named forthe Hindu goddess Ganga, the Ganges is reveredby Hindus, who consider its waters to be sacred.

The land area through which the Ganges flowsis known as the Ganges Plain. Almost all of theplain has been cleared of grasslands and forests tomake way for crops, such as rice, sesame, sugar-cane, jute, and beans. As India’s most agriculturallyproductive area, the Ganges Plain is the world’slongest alluvial plain, an area of fertile soildeposited by river flood waters. The Ganges Plainalso is India’s most densely populated area.

The Holy River The GangesRiver is important to fishing, commerce, and agriculture. Millions of Hindus visitthe river for ritual bathing (inset).

Human-Environment Interaction What crops are grown on the Ganges Plain?

C h a p t e r 2 3 573

Natural ResourcesSouth Asia has a variety of natural resources.

Dependent on these resources for their livelihood,South Asia’s large populations and the fragilenature of some of their environments are ongoingchallenges.

WaterThe rivers of South Asia provide alluvial soil,

drinking water, transportation, and hydroelectricpower to the region’s large, growing population.They also provide fish for local use and export.

Water resource management challenges SouthAsia because rivers cross national boundaries. Still,countries in the region sometimes work togetheron various projects. For example, India funded theChhukha Hydel hydroelectric project in Bhutan. Inreturn, India receives some of the energy gener-ated there. Countries in the region also build damsto provide hydroelectric power and to open up

new farmlands by ensuring consistent levels ofwater for irrigation. Mountainous Nepal, with itsmany waterfalls, has the potential for creatinglarge amounts of hydroelectricity.

Such massive projects, however, often have draw-backs as well as benefits. Dam projects in India meetwith resistance when they threaten to flood existingsettlements. In Pakistan one of the largest dams inthe world, the Tarbela Dam, will soon be unusable,choked with built-up silt from the Indus River.

Energy ResourcesPetroleum reserves are known to lie along

India’s northwest coast, near the Ganges Delta,and in northern Pakistan. Offshore exploration inthe Arabian Sea may eventually yield oil. Overall,though, South Asia depends on imported oil.

Waterfalls in Nepal Twin waterfalls in the Annapurna region of Nepal cut through the sheer rock face of a Himalayan peak.

Human-Environment Interaction How might waterfalls benefit Nepal’s economy?

Student Web Activity Visit the Glencoe World GeographyWeb site at tx.geography.glencoe.com and click on Student WebActivities—Chapter 23 for an activity on the formation of theHimalaya and attempts to reach the summit of Mount Everest.

Checking for Understanding1. Define subcontinent, alluvial

plain, mica.

2. Main Ideas On a table like theone below show examples of thephysical features and naturalresources of South Asia.

Critical Thinking3. Making Comparisons How does the

landscape of the Himalaya differfrom that of the Deccan Plateau?How do these differences affectpeople’s lives?

4. Identifying Cause and Effect Whyare population densities so highon the Ganges Plain?

5. Problem Solving How would youaddress the problem of overcut-ting trees in Nepal? How doesyour solution affect the timberindustry?

Analyzing Maps6. Region Study the physical-political

map on page 571. What areas ofSouth Asia would you expect tobe most agriculturally productive?Why?

Country Physical Features Natural Resources

574 U n i t 8

7. Managing Resources Thinkabout the physical geogra-phy of South Asia. Create asketch map highlightingpotential sites of conflict overwater management amongthe countries of South Asia.

Applying Geography

erosion. To preserve the fragile Himalayan environ-ment, the government of Nepal is implementingconservation plans.

Timber resources also include India’s prized san-dalwood. Rain forests in southwest India yield saland teak woods for export. To protect its rain forests,Sri Lanka since 1977 has banned timber exports.

Natural gas fields are found in southernPakistan, in India’s Ganges Delta, and inBangladesh. India has a major uraniumdeposit north of the Eastern Ghats. MostSouth Asians, however, rely on energyfrom hydroelectricity, fuel wood, and coal.

MineralsSouth Asia’s mineral resources are

rich, diverse, and widespread. India is aleading exporter of iron ore, and sup-plies 90 percent of the world’s mica, alayered rock used in making electricalequipment. Deposits of manganese,chromite, and gypsum still await devel-opment. Nepal produces mica and smallamounts of copper. Sri Lanka is one ofthe world’s largest producers of graphite,the material used for the “lead” in pen-cils. Sri Lanka’s other major mineralresources include sapphires, rubies, andabout 40 other varieties of precious andsemiprecious stones.

TimberTimber is important to South Asia. The forests of

Nepal and Bhutan contain conifers, including silverfir, and hardwoods such as oak, magnolia, beech,and birch. Severe overcutting threatens Nepal’stimber, however, and could result in massive soil

Timber Plantation In Bhutan, 90 percent of the workforce makesits living in agriculture and forestry.

Human-Environment Interaction How does overcuttingimpact the environment?

C h a p t e r 2 3 575

Guide to ReadingConsider What You KnowThe countries of South Asia often are affected by natural disasters ofsome kind. For example, in 1998Bangladesh suffered the effects of a terrible flood. What problemscan flooding cause?

Read to Find Out• What are the five major climate

regions of South Asia?

• How do seasonal weather pat-terns present challenges to theregion’s economy?

• How do elevation and rainfallaffect South Asia’s vegetation?

Terms to Know• monsoon

• cyclone

Places to Locate• Bay of Bengal

• Great Indian Desert

Climate andVegetation

A Geographic ViewThe Breath of LifeThe eagle soared even higher in theupdraft as I picked my way alongthe dark rocks beside the ArabianSea. The winds shifted withpromise, deepening the resonanceof the surf, muffling even the crowsthat cackled and lurched along the seawalls. The water grewchoppy, and the black thorns of fishermen’s sails scratchedthe horizon. Surely the time [of the monsoon] was at hand.

—Priit J. Vesilind, “Monsoons: Life Breath of Half the World,” National Geographic, December 1984

Journalist Priit Vesilind captures in words the ten-sion of waiting for South Asia’s seasonal rains. The region, with itshot climates, comes alive when the rain-bearing winds sweep in.

South Asia’s ClimatesSouth Asia’s climate and vegetation regions are a study in con-

trasts. Much of the subcontinent lies south of the Tropic of Cancer andhas tropical climates with diverse vegetation. In the north and thewest, however, the climate varies widely, from the highlands of theHimalaya to the deserts around the Indus River, where little vegeta-tion grows.

Tropical and Subtropical ClimatesTropical rain forest climates, with a variety of vegetation, are located

along the western coast of India, near the Ganges Delta in Bangladesh,

Rain-swollen Mahandi River, India

Lucknow

Kolkata(Calcutta)

Lucknow

Dhaka

Karachi

Mumbai(Bombay)

Chennai(Madras)

Kanpur

Hyderabad

Colombo

Rawalpindi

Delhi

Chittagong

80°E70°E60°E

30°N

20°N

10°N

90°E

Lahore

Pune

Bangalore

TROPIC OF CANCER

Indian Ocean

ArabianSea

Bay ofBengal

Two-PointEquidistant projection

400

4000 mi.

0 km

N80°E70°E60°E

30°N

20°N

10°N

90°E

TROPICOF CANCER

INDIaN OCEaN

ArabianSea

Bay ofBengal

Rawalpindi

Lahore

Delhi

Karachi KanpurLucknow

Mumbai(Bombay)

Pune

Hyderabad

Bangalore

Chennai(Madras)

Kolkata(Calcutta)

Colombo

Dhaka

Chittagong

Two-Point Equidistant projection

400

4000 mi.

0 km

N

576 U n i t 8

and in southern Sri Lanka. In the path of seasonalrains from the southwest, South Asia’s rain forestsabsorb great quantities of moisture. The rain forestsin western Sri Lanka, in southwest India, and inareas north of the Bay of Bengal have ebony trees,lush vines, and orchids. Tropical coniferous anddeciduous trees surround the rain forests near theWestern Ghats. In hot, damp Bangladesh, tropicalforests of bamboo, mango, and palm trees thrive.The Sundarbans, a swampy area in southwesternBangladesh, has the world’s largest protected man-grove forest.

A tropical savanna climate surrounds the centralIndian steppe and also is found in eastern Sri Lanka.The grasslands and tropical-moist deciduous forestsof the savanna experience wet and dry seasons.In Sri Lanka dry evergreen forests and moist

deciduous forests give way to drier grasslands athigher elevations.

A band of humid subtropical climate extendsacross Nepal, Bhutan, Bangladesh, and the north-eastern part of India. Temperate mixed forests stretchacross the borders of these countries in this area.

Highlands ClimatesThe coldest climate region of South Asia lies along

its northern edge. In the Himalayan highlands andKarakoram peaks, snow never disappears. At thehighest elevations, little vegetation can survive. Far-ther down these slopes, however, the climate turnsmilder and more temperate. In the upper area of thismore temperate zone, coniferous and hardwoodtrees flourish. Grasslands and stands of bamboocover the lower Himalayan foothills.

South Asia: Climate Region South Asia: Natural Vegetation

Find NGS online map resources @ www.nationalgeographic.com/maps

2. Applying Geography Skills How is vegetationrelated to climate in the northern part of South Asia?

MAP STUDY

Tropical forest Temperate grassland

Desert scrub and Highlands (vegetationdesert waste varies with elevation)

Tropical rain forestTropical savanna

SteppeDesert

Tropical

Dry

Humid subtropical

Highlands (climatevaries with elevation)

Mid-Latitude

1. Interpreting Maps Where are tropical rain forest climates located in South Asia?

Averag

e Mo

nth

ly Precipitatio

n

Ave

rag

e M

on

thly

Tem

per

atu

re

MonthsMonthsDNOSAJJMAMFJDNOSAJJMAMFJ 0/0

20/51In./Cm

0/–18

100/38°F/°C

8/20

12/30

16/41

4/10

60/16

40/4

20/–7

80/27

Averag

e Mo

nth

ly Precipitatio

n

Ave

rag

e M

on

thly

Tem

per

atu

re

0/0

20/51In./Cm

0/–18

100/38°F/°C

8/20

12/30

16/41

4/10

60/16

40/4

20/–7

80/27

UNITED STATES

ALASKA

INDIA

New Delhi, India 29° N, 77° E714 ft (218 m) above sea level

Houston, Texas, U.S.30° N, 95° W40 ft (12 m) above sea level

Source: National Climatic Data Center and Carbon Dioxide Information Analysis Center

C h a p t e r 2 3 577

Dry ClimatesAlong the lower Indus River, a desert climate

keeps the land arid and windswept. The GreatIndian Desert (Thar Desert) lies to the east of theIndus. The vegetation here is desert scrub, low,thorny trees, and grasses. Livestock graze in someareas, and irrigation makes it possible to growwheat near the Indus River. Much of this area,however, remains wasteland.

Surrounding this desert, except on the coast, isa steppe. Few trees grow in this semiarid grassland.

In northwestern India annual rainfall averages lessthan 20 inches (51 cm). Another steppe area runsthrough the center of the Deccan Plateau between theEastern and Western Ghats. The Ghats block rainfallhere, making the area relatively arid. Dry, deciduousforests cover vast stretches of India’s interior.

MonsoonsMuch of South Asia experiences three distinct

seasons—hot (from late February to June), wet(from June or July until September), and cool (from

GRAPH STUDY

Comparing Climate Regions: India and the United States

1. Interpreting Climographs What is the aver-age December temperature and precipitation in each city?

2. Applying Geography Skills How might climate affect patterns of settlement and population distribution in the northern part of India? In the south central United States?

TROPIC OF CANCER

N

Two-Point Equidistant projection400

4000

0

mi.

km

TROPIC OF CANCER

N

Two-Point Equidistant projection400

4000

0

mi.

km

578 U n i t 8

Winter winds

Summer winds

Monsoons

The same fields in west central India before (topright) and after (bottom right) the arrival of the monsoon rains reveal a stunning contrast betweenthe dry and wet seasons.

Find NGS online map resources @ www.nationalgeographic.com/maps

South Asia: Monsoons

MAP STUDY

1. Interpreting Maps From what direction do thewinter monsoon winds come? What kind ofweather do they bring?

2. Applying Geography Skills Describe the impactof the summer monsoon winds on South Asia.

C h a p t e r 2 3 579

Economics

Natural DisastersBoth the high temperatures of the hot season

and the heavy rains of the wet season are mixedblessings in South Asia. High temperatures allowfarmers to produce crops, including the rice thatmany in Bangladesh and India depend on, year-round as long as water supplies are good. Theextreme heat can result in evaporation and dried-out, nutrient-poor soils, however.

The monsoon winds also have benefits and draw-backs. Rainfall waters crops, but areas outside thepath of the monsoon, such as the Deccan Plateauand western Pakistan, may receive little or no rain-fall during the year. When the people ofBangladesh are planting rice, and those on theGanges Plain are planting their winter crops, otherareas are scorched by drought.

Too much rain also can be a problem. In the low-lying delta country of Bangladesh, monsoons maycause flooding that kills people and livestock,leaves thousands homeless, and ruins crops.

Another kind of weather catastrophe sometimesstrikes South Asia. A cyclone is a storm with highwinds and heavy rains. A 1999 cyclone struckOrissa, India, with winds of more than 160 milesper hour (257 km per hour) and waves over 20 feet(6 m) high. The storm killed nearly 10,000 peopleand caused more than $20 million in damages.

Checking for Understanding1. Define monsoon, cyclone.

2. Main Ideas On a chart like the onebelow, fill in the names of differentareas of South Asia, and then writein the type of climate and vegeta-tion found in each area.

Critical Thinking3. Analyzing Information Analyze

the reaction of South Asia’s envi-ronment to the monsoons.

4. Decision Making Suppose thatyou wanted to establish a lumberbusiness in South Asia. Wherewould you locate it? Why?

5. Comparing and Contrasting Arethe effects of the very hot tem-peratures in much of South Asiamore positive or more negative?Explain.

Analyzing Maps6. Region Compare the maps of

South Asia’s climate and vegeta-tion on page 576. Explain how climate and vegetation arerelated in the region.

7. Visiting Sri Lanka Thinkabout the attractions of SriLanka’s climate and vegeta-tion. Write a descriptiveparagraph urging people to visit and enjoy Sri Lanka’snatural features.

Applying Geography Location Climate Vegetation

October to late February). These periods depend onseasonal winds called monsoons. During the coolseason, dry monsoon winds blow from the north andnortheast. In the hot season, warm temperatures heatthe air, which rises and triggers a change in winddirection. Moist ocean air then moves in from thesouth and southwest, bringing monsoon rains.

Monsoon RainsThe monsoon rains are heaviest in eastern South

Asia. When the rains sweep over the Ganges-Brahmaputra delta, the Himalaya block them frommoving north. As a result, the rains move west tothe Ganges Plain, bringing rainfall needed forcrops. It is no wonder, then, that people celebratethe monsoon rains, as an Indian writer describes:

“ Kulfi [a woman shopping] watched withunbelieving elation as the approachingsmell of rain spiked the air like a flower,as the clouds shifted in from the east. . . .Outside, she could hear the sound ofcheering from the bazaar. ‘Rain, rain,rain, rain.’ And in the streets, shewatched the children leap like frogs,unable to keep still in their excitement.”Kiran Desai, Hullabaloo in

the Guava Orchard, 1997

580 U n i t 8580 U n i t 8

The Glencoe Skillbuilder Interactive Workbook,

Level 2 provides instruction andpractice in key social studies skills.

Reading an Elevation ProfileIf you were planning a long-distance cycling expedition, you

might want to check elevations of places along your route. Elevation, the vertical distance above sea level of a place orlandform, can be shown in a number of ways. An elevation profile gives you elevation information in a visual form.

Learning the SkillAn elevation profile presents

visual information about the ele-vation of a particular area, route,or landform in a two-dimensionalway. The base of an elevation pro-file is sea level, the point fromwhich land elevation is measured.A vertical scale measures elevationabove sea level.

Reading an elevation profile issimilar to reading a line graph.The vertical scale corresponds tothe y-axis. In some elevation pro-files, a horizontal scale, corre-sponding to the x-axis, measuresthe length of the route, area, orlandform in miles or kilometers.The profile, or top edge of thelandscape shown, corresponds tothe line in a line graph. This lineshows elevation at specific points.Some elevation profiles provideinformation on more than oneroute, area, or landform, usingdifferent colors or patterns to dis-tinguish each profile.

Follow these steps to read anelevation profile:

• Look at the landscape profileas a whole. This will give youa general sense of the varia-tions in elevation shown.

• Find the highest and lowestpoints. Use the vertical scaleto find their elevations. Calcu-late the approximate differ-ence in elevation betweenthe highest and lowest points.

• Use your finger to trace theprofile. If your finger mustjump up and down to followthe profile, the area has dra-matic differences in elevation.

• If more than one area or land-form is profiled, follow theprocedure for each profile.Then use the information tocompare the profiled areas.

Practicing the SkillStudy the elevation profile

contrasting the Rocky Mountainswith the Himalaya. Then answerthese questions.

1. What is the highest peak inthe Rocky Mountains? Abouthow many feet above sealevel does it rise?

2. What is the approximate ele-vation of the highest peak inthe Himalaya?

3. What is the approximate difference in elevationbetween the highest point in the Rocky Mountains and

the highest point in theHimalaya?

4. Which range contains thegreater variation in elevation?

5. Which range stretches over agreater distance?

6. What does the elevation pro-file reveal about the relativeelevations of these mountainranges?

26,247 ft

19,685 ft

13,123 ft

6,562 ft

8,000 m

6,000 m

4,000 m

2,000 m

S e a l e v e l

Mt. Elbert

Mt. Everest

Rocky Mountains

Himalaya

0 mi. 200

0 km 200

Elevation Profiles:The Rockies and the Himalaya

Use a map to choose a bicycleroute across your state. Identifyseveral key points along your route,and check the elevations for eachone. Then create an elevation pro-file of your route. Note the highestand lowest points on your profile.Where would your bike ride be eas-iest? Most difficult?

C h a p t e r 2 3 581

Key Points• The landforms of South Asia include mountains,

plateaus, plains, and islands.

• South Asia has three great river systems—theIndus, Brahmaputra, and Ganges—and theworld’s longest alluvial plain.

• South Asia has few significant oil reserves, buthas substantial mineral deposits, including ironore and mica.

Organizing Your NotesCreate an outline using the for-mat below to help you organizeyour notes for this section.

Terms to Know• monsoon• cyclone

Key Points• South Asia has highlands, tropical, and desert

climates.

• The monsoon is a seasonal change in winddirection that brings heavy rainfall to much ofSouth Asia from June to September.

• South Asia’s vegetation is affected by elevation,rainfall, and human activity.

Organizing Your NotesUse a table like the one below tohelp you organize the notes youtook as you read this section.

Terms to Know• subcontinent• alluvial plain• mica

SECTION 1 The Land (pp. 569–574)

SECTION 2 Climate and Vegetation (pp. 575–579)

SUMMARY & STUDY GUIDE

South Asia’s LandI. A Separate Land

II. A Land of Great VarietyA. The HimalayaB. Other Northern Landforms

Climate Country Region Vegetation or Area

tropical ebony trees,rain forest lush vines,

orchids

Along the Ganges,Varanasi, India

2. Comparing and Contrasting What arethe advantages and disadvantages of themonsoons to South Asia?

3. Predicting Consequences Using a webdiagram like the one below, show the conse-quences to the people of South Asia of possi-ble weather conditions. Then choose oneconsequence and describe it in detail.

Reviewing Key TermsWrite the letter of the key term that best matcheseach definition below.

a. subcontinent d. monsoonsb. alluvial plain e. cyclonec. mica

1. seasonal winds

2. a storm with high winds and heavy rains

3. a layered mineral used to make electricalcomponents

4. a very large, distinct landmassthat is part of a continent

5. an area of rich, fertile soil foundalong a river

Reviewing FactsSECTION 1

1. Why might the region of SouthAsia be referred to as “a land ofgreat variety”?

2. How have the mountains of theVindhya Range affected the peo-ple of India?

3. Why is the management of waterresources important in SouthAsia?

SECTION 24. Where can you find a steppe cli-

mate region in South Asia?

5. When do the three seasons foundin much of South Asia occur, andhow would you describe each?

6. What factors enable South Asia’srain forests to thrive?

Critical Thinking1. Identifying Cause and Effect

In what way are the Himalayaresponsible for the richness of thesoil in the northern plains of theIndian subcontinent?

Locating PlacesSouth Asia: Physical-Political Geography

Match the letters on the map with the places and physical features of South Asia. Write your answers on a sheet of paper.

1. Arabian Sea2. Bay of Bengal3. Ganges River4. Deccan Plateau

5. Sri Lanka6. Himalaya7. Brahmaputra

River

8. Great Indian Desert

9. Pakistan10. Indus River

A

B

E

F

H

IJ

G

D

C

10°N

20°N

30°N

60°E 70°E 80°E 90°E 100°E

TROPIC OF CANCER

Two-Point Equidistant projection400

4000 mi.

0 km

N

ASSESSMENT & ACTIVITIES

582 U n i t 8

South Asia’s Weather

C h a p t e r X 583

Note that the question asks for thedifference in height between the twolocations. You can arrive at the answer

by subtracting.

Self-Check Quiz Visit the Glencoe WorldGeography Web site at tx.geography.glencoe.comand click on Self-Check Quizzes—Chapter 23 toprepare for the Chapter Test.

Using the Regional AtlasRefer to the Regional Atlas on pages 560–563.

1. Location What mountains form the bor-der between East Asia and South Asia?

2. Place Compare the political map with thepopulation density map. Where is the area oflowest average population density along theIndia-Pakistan border?

Thinking Like a GeographerAnalyze the effects of physical geographic patternson population in South Asia. What patterns favorhigh population density? Low population density?

Problem-Solving ActivityContemporary Issues Case Study Whennatural disasters strike populated areas, their impactis worse in areas of high population density. In agroup, research a recent natural disaster in SouthAsia, such as the 1999 cyclone in Orissa or the 1998flood in Bangladesh. Find out the causes of the dis-aster and how it affected the area’s population andnatural resources. What efforts were taken follow-ing the disaster? Then, focusing on one of theseefforts, present your group’s findings to the class.

GeoJournalDescriptive Writing Using your GeoJournal,write a description about the ways South Asianshave adapted to or modified their environment.Then compare human-environment interactionin South Asia with that in your state and localcommunity.

Technology ActivityUsing an Electronic Spreadsheet

Use a spreadsheet program to organize informa-tion about elevations in South Asia. List at least sixSouth Asian countries in the left column of a spread-sheet. Use a world atlas to find the highest point ineach country. Then list the heights in the second col-umn of the spreadsheet. Use the graphics feature ofthe program to make a bar graph to compareheights.

Study the elevation profile. Then choose thebest answer for the following multiple-choicequestions. If you have trouble answering thequestions, use the process of elimination to narrow your choices.

1. About how much higher is Mt. Everestthan the Indus River?

A 2,500 feet C 25,000 feetB 19,000 feet D 1,900 feet

C h a p t e r 2 3 583

0

5

10

15

20

25

30

2. Based on elevation, which locations on theprofile would be unsuited for farming?

F Ganges PlainG Great Indian DesertH Mt. Everest and the Great Indian DesertJ Mt. Everest

Read the question carefully. The phrasebased on elevation is important. TheGreat Indian Desert is unsuited to

farming, but not because of its elevation. Once youapply the standard asked for in the question, it is easy to eliminate wrong answers.

Elevation Profile

0 mi.

0 km 500

500

Sea level

2,000 m

4,000 m

6,000 m

8,000 m

6,532 ft

13,123 ft

19,685 ft

26,247 ft

BRAHMAPUTRA RIVER

INDUSRIVER

GREATINDIANDESERT GANGES

PLAIN

MT. EVEREST

HIMALAYA

Measuring the speedof a river or stream

is the first step in deter-mining the river’s flow—the volume of waterdischarged over a periodof time. Flow is calculatedby multiplying the veloc-ity, or speed, of a river(measured in feet ormeters per second) by thearea of the cross sectionof the river (a cuttingmade across, measured insquare feet or squaremeters). Further calcula-tions will yield the aver-age flow in cubic feet per second or in gallons perday. Why measure theflow of a river or stream?This information can help

water management engineers plan for emergenciessuch as drought or flooding.

Natural flow varies throughout the year, especiallyin South Asia, where seasonal weather patterns andhuman interaction with the environment affect thegreat river systems.

River and Stream SpeedMaterials

• Tape measure• Ball of string or twine• 4 wooden dowels or sticks• Several medium-sized oranges or large craft

sticks painted in bright colors• Stopwatch• Writing materials

ProceduresIn this activity, you will use a simple methodto measure the approximate speed (velocity)at which water moves in a stream.

1. Take all materials to a local stream that isno more than a few yards wide and is rela-tively free from vegetation and rocks.

2. Set up the measuring marks. Fix a dowelor stick in the ground, and tie one end ofthe string to it. Then toss the ball of stringto a student on the opposite bank of thestream. Have the second student pull thestring taut, tie it to another dowel fixed inthe ground, and cut the end of the string. This will be Mark 1.

3. Use the tape measure to determine a point10 feet (3 m) downstream from Mark 1.Insert another dowel at this point, andrepeat the process of stringing a line acrossthe stream, parallel to Mark 1. This will beMark 2. If the stream you are measuring isvery shallow or slow-moving, set the twolines only 5 (1.5 m) feet apart. If the stream is very fast, set the two lines 15 (4.6 m) feet apart.

584 U n i t 8

Flow calculations helppeople make effective use of river systems.

C h a p t e r 2 3 585

Scientists have used the AcousticDoppler Current Profiler (ADCP) to measure theflow of the Brahmaputra River in Bangladesh. TheBrahmaputra often has severe floods. The ADCPallows scientists to measure river flow safely andaccurately during flood conditions. The ADCPattaches to a boat and is connected to a computerthat computes the river’s flow, using data aboutdepth, current, and direction.

4. Position an observer at Mark 1. Position another observer with thestopwatch at Mark 2. Have a thirdstudent go to a point several feetupstream and toss an orange or apainted craft stick into the water.

5. When the object crosses under thestring at Mark 1, the first observerstationed there yells “Go!” and thesecond observer starts the stopwatch.When the object crosses under thestring at Mark 2, the second observerstops the stopwatch.

6. Record the time, in seconds, that ittook the object to pass from Mark 1 to Mark 2.

7. Repeat the process several times, record-ing the elapsed seconds. Calculate the aver-age elapsed time in seconds. Then divide thedistance in feet or meters between Mark 1and Mark 2 by the average elapsed time.The result is the average stream speed, measured in feet or meters per second.

8. Note the weather for the days precedingyour measurements. Did it rain, or werethe days sunny? Why might this informa-tion be important?

1. Did you expect to find a faster or slower

average stream speed, or were your findings

consistent with what you expected?

2. How much variation in elapsed time did you

observe when taking repeated measure-

ments at the same site?

3. If you were asked to measure the speed of

a river 100 yards (91 m) wide, how would

you adapt this activity?

4. Predicting Consequences How might your

measurement change if you dammed off the

right half of the stream in the 10-foot (3-m)

span you measured?

Lab Report

Flow calculations are used to helpdesign the irrigation systems thatmake South Asian desert lands ableto be farmed.

Find Out MoreContact a public works department for informa-tion on how flow calculations are used in yourarea (possibilities include environmental man-agement, flood control, recreational use, agricul-tural irrigation, and urban water resourcemanagement). Choose one of these uses toresearch. Share your findings with the class.