COMBINATIONSA GEOGRAPHIC “BIG IDEA”

WITH MANY CONSEQUENCES IN

SOUTH ASIA

Combinations of conditions can help us understandmany of the geographic features in South Asia,

including patterns of mountains, rainfall, river flow,British colonialism, cotton production, railroads,

trade, population, post-colonial partition,and modern territorial disputes.

The subcontinentof South Asia is

almost half as largeas Europe.

Like Europe, South Asiais basically a large peninsula.

It extends out from Eurasiainto the Indian Ocean, whereit separates the Arabian Sea

from the Bay of Bengal.

You could put about eight statesas big as Texas into South Asia,

but most of this regionis closer to the equator (and therefore hotter)

than South Texas.

Here is Texas,at the same scale

and proper latitude.

Geologically,South Asia

is a separatecrustal plate

(a moving piece of the earth’s outer “shell”)

In fact,it used to beconnected toAntarctica,Australia,

and Africa.

Geologically,South Asia

is a separatecrustal plate(a moving pieceof the earth’s outer “shell”)

Now, it is moving

northwardat a rateof about2 inchesper year.

That is very fast(for a geologic process).

It is fast enoughto push upthe highest

mountain rangein the world.

The Himalaya Mountainsaverage more that four miles high.

The highest peaks arealmost twice as high

as the tallest mountains in Colorado or California.

That is high enoughto block the jet stream,the west-to-east flow of air

high in the atmosphere.

The jet stream has to goaround the mountains.

This combination of conditions

jet stream + mountains

is responsible for triggeringthe famous Indian monsoon.

Definition: a monsoon is a seasonal reversal of wind direction that brings heavy rain in summer and very dry weather in winter

Here is how the monsoon works:

1. In winter, the continent is cold.

2. The jet stream is pushed to the south side of the mountains.

3. Air pressure is high, and

4. Winds blow toward the southwest, from the land to the ocean.

As a result, it rains or snowsonly on the offshore islandsand a few high mountains.

Most of the subcontinentis extremely dry.

NOTE:

The cold air is up north.

Remember, most of Indiais closer to the equator

than Texas, so India itself is really quite warm

as well as dry in “winter.”

Then:

1. In summer, the continent is warm.

2. The jet stream flows around the north side of the mountains.

3. Air pressure is low, and

4. Winds blow toward the northeast, from the ocean to the land.

As a result, heavy rainsfall on most of the land,especially on the hillsand high mountains.

Some places can getthirty feet of rain in mid-summer –twice as much as Atlanta, Boston,

Chicago, and Houston put together.

Here is another look at the winter mapof wind and rain, without all the explanations.

Here is another look at the summer map.

Note how this arearemains dry.

Where the jet stream(blowing from west to east)

“piles up” against the high mountains,

air is pushed downwardand makes a desert.

This combinationof conditions

makes this areaone of the hottest and driest deserts

in the world.

Satellites have recordedsurface temperaturesabove 155 degrees!

Hold that thoughtfor a few minutes.

The heavy summer rainscombine with the high mountainsto make some really big rivers.

And remember, since the rainscome in less than half the year,

these rivers tend to flood in summerand almost disappear in winter.

Did you notice over here,where several large rivers flow parallel to each other?

What could cause that?If your hypothesis is

that the crustal collisionmade these parallel

ranges of mountains,you are right.

Parallel ridges separated by deep canyonsmake travel very difficult in this region.

The combinationof a bone-dry desert,

the world’s highest mountains,and the parallel canyons

form a very effective“natural fence”

around South Asia.

With travel difficult,overland trade almost impossible,and even military action unlikely,

it is not surprisingthat South Asia developed

a kind of cultural independence.

This region hadits own religion – Hinduism –

and many unique cultural ideas,including the caste system,

and distinctive styles of art, music, cooking,

theater, and dance.

There is one big exceptionto this idea of cultural isolation.

The combination of peninsular shapeand seasonally reversing winds

made it possible for sailors to cross the Arabian Sea and Bay of Bengal(even way back in Roman times).

These traders carriedsilks and fine pottery from China,glass, cloth, and iron from Rome,

spices from Arabia and Indonesia, and gold and ivory from Africa.

At the time of the Islamic caliphs(say around the year 900)

their role as intermediariesin the trade between Europe and China

made Arabian and South Asian citiesamong the richest in the world.

Then Spain finally reconquered Gibraltar.

Europeans beganto sail around the world,

making colonies overseasand factories at home.

A different combinationof conditions gave

South Asia a new role.

Remember thatthe crustal plate

is moving northward.

As it crossed a hot spotdeep inside the earth,

volcanoes eruptedand spread lava

over a large area.

When combined witha long growing season

and monsoon rain,

these volcanicand floodplain soils

make excellent fieldsfor crops like cotton.

And England neededa lot of cotton

for its new factories.

With its powerful navy,England conquered

South Asia and madeit into a colony.

After a very long struggle (you can read about Gandhi and other resistance leaders

on the internet),

South Asia finallygained independence.

But there was a problem.

The clickable mini-atlashas three primary documents

that help explain the issue.

This old map(from the Imperial Gazetteer of India)

shows the areasof South Asia

where Hinduismwas the main religion.

Note that Hindusare less than

40 percentof the populationin several places.

Note that Hinduswere less than

40 percentof the populationin several places.

This old map(from the same

Imperial Gazetteer)

shows the areaswhere Islam wasthe main religion.

Islam and Hinduismwere the most importantreligions in the region,

but other religionswere locally important

in several areas.

The political leaderstried to solve the problem

of religious differencesby “partitioning” the area

into several separate countries.

Unfortunately,the resulting borders

do not pay much attentionto things like language

or the flow of water.

For example, every major river in the region starts in one country

and goes through anotheron its way to the ocean.

The area called Kashmiris the focus of one dispute

over how the land and watershould be divided.

Part of the borderis deliberately left off of this map –

a university colleague of mine,an well-known expert on South Asia,was barred from traveling in this areabecause he drew one of the borders

in the wrong place on one of his maps.

South Asia today is a regionthat has more than a billion people

(more than 4 times as many as the U.S.)

and a rapidly growing economy.

Unlike some other colonial regions,South Asia “inherited”

two valuable legacies - a superb railroad network

and strong technical universities.

As a result, South Asia todayhas become a prominent “player”

in several hi-tech industries,such as software design,

movie and music production,and computer-telecom help desks.

SummarySouth Asia has some important combinations of geographic conditions:

1. Monsoons and mountains combine to make large rivers.

2. Mountains and deserts combine to make transportation difficult, which in turn allowed the area to develop independently.

3. Volcanic soils and monsoons combine to make good cotton fields.

4. Cotton and military isolation combined to make South Asia a very desirable colony for England during the colonial era.

5. Post-colonial borders that divide the watersheds of major rivers make water management and pollution control difficult.

6. Deep religious differences between and within countries combine with nuclear weapons to create tensions.

7. Good engineering schools and English language ability combine to support hi-tech industries and call centers.

(Think Bollywood!)

QUESTIONSSECTION

The How does the sizeof South Asia compare

with Europe?

What do you calla landform that

sticks out into an ocean, like a large nose or thumb?

What are some consequencesof the fact that most of India

is closer to the equatorthan Texas?

Here is Texas,at the same scale

and proper latitude.

Geologically,South Asia

is a separatecrustal plate

(a moving piece of the earth’s outer “shell”)

We think of itas part of Asia,but what land

was connectedto it in the

geologic past?

Geologically,South Asia

is a separatecrustal plate(a moving pieceof the earth’s outer “shell”)

How fastis this partof the crust

moving?

What is the mainconsequence

of this “collision”between

crustal plates?

How do the Himalayas compare with the highest mountains

in the United States?

How can a mountain rangehelp cause the wind reversal

called the monsoon?

Definition: a monsoon is a seasonal reversal of wind direction that brings heavy rain in summer and very dry weather in winter

Describe the situation in winter:

1. air temperature?

2. position of the jet stream?

3. air pressure?

4. wind direction?

5. rainfall?

Describe the situation in summer:

1. air temperature?

2. position of the jet stream?

3. air pressure?

4. wind direction?

5. rainfall?

What happenswhere the jet stream

“piles up” against the high mountains?

What is the resultin this area when

the jet stream “collides”with the high mountains?

What happens in this areawhen the monsoon winds

hit the slopes of the Himalayas?

Why is it important to knowthat the summer monsoonlasts only half of the year?

What causes these riversto flow parallel to each other?

What is the main effect of that?

What is the consequenceof this combination

of a bone-dry desert,the world’s highest mountains,

and the parallel canyons?

Describe some of theunique cultural features

that developed as a result.

What is the big exceptionto the rule about cultural isolation

in South Asia?

What commodities were carried in each direction?

What were some consequencesof those trading links?

What happenedafter Spain finally

reconquered Gibraltar?

How did this affectSouth Asia?

How can the motionof the crustal platescause the formation

of a large bodyof rich volcanic soil?

Describe howthis volcanic soil

helped make Indiaa very valuable colony

for Great Britain?

Describe how Gandhiand other resistance leaders

finally helped Indiagain independence.

What is thesignificance

of this old mapshowing the areaswhere most peoplefollow Hinduism?

What is thesignificance

of this old mapshowing the areaswhere most people

follow Islam?

What is thesignificance

of this old mapshowing the areaswhere most peoplefollow Buddhism,

Jainism, or Sikhism?

What was the nameof the process of dividingSouth Asia into severalindependent countries?

What are some problemscaused by the fact

that the country borderswere drawn primarily

on the basis of religion?

Describe the natureof the dispute

over the regioncalled Kashmir.

How large is the populationof South Asia today, compared

to the United States?

Describe two valuable “legacies”that South Asia “inherited”from the British colonists.

What are some modern industriesthat are favored by this history?

What unique geopolitical problemfaces the people in the region

that is called South Asia?